RFC3816

From RFC-Wiki

Network Working Group J. Quittek Request for Comments: 3816 M. Stiemerling Category: Standards Track NEC

                                                      H. Hartenstein
                                             University of Karlsruhe
                                                           June 2004
 Definitions of Managed Objects for RObust Header Compression (ROHC)

Status of this Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2004).

Abstract

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes a set of managed objects that allow monitoring of running instances of RObust Header Compression (ROHC). The managed objects defined in this memo are grouped into three MIB modules. The ROHC-MIB module defines managed objects shared by all ROHC profiles, the ROHC-UNCOMPRESSED-MIB module defines managed objects specific to the ROHC uncompressed profile, the ROHC-RTP-MIB module defines managed objects specific to the ROHC RTP (Real-Time Transport Protocol) profile, the ROHC UDP (User Datagram Protocol) profile, the ROHC ESP (Encapsulating Security Payload) profile, and the ROHC LLA (Link Layer Assisted) profile.

Introduction

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes a set of managed objects that allow monitoring of running instances of robust header compression.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, RFC 2119 RFC2119.

The Internet-Standard Management Framework

For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 RFC3410.

Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB

module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 RFC2578, STD 58, RFC 2579 RFC2579 and STD 58, RFC 2580 RFC2580.

Overview

This section describes the basic model of RObust Header Compression (ROHC, RFC3095) used when developing the MIB modules for ROHC described in the following sections.

ROHC presents a framework for IP header compression that allows flexible adjustment of compression efficiency versus robustness against channel errors depending on the underlying channel characteristics.

ROHC introduces header compressors/decompressors at the end-points (interfaces) of (wireless) channels on which packets with compressed headers are transferred. ROHC exploits the temporal redundancy in successive packet headers of a packet flow by storing non-changing fields of the headers as well as reference values of predictably changing fields as context information. When the context information for a packet flow is also established at the decompressor, only delta-information and unpredictably changing header fields have to be sent over the channel.

This document specifies MIB modules in order to provide a means for managing ROHC implementations via SNMP and within the IETF management framework. The objects defined support configuration management, fault management and performance monitoring.

For configuration management implementation parameters (see Section 6.3 of RFC3095) and configuration parameters (including the ones specified in Section 5.1.1 of RFC3095 and in Section 5.1.1 of RFC3242) can be verified by using the MIB modules specified below.

For fault management compressor/decompressor state and mode can be checked.

For performance management a set of statistics is provided including the number of flows that have used ROHC, the current and long term compression ratio, the number of reinitializations and the number of packets sent or received with different header types.

Structure of the MIB modules

This section presents the structure of the MIB modules that are specified in Section 5. Basically, the MIB is structured according to the ROHC architecture described in RFC3759.

ROHC is an evolving technology. RFC3095 specifies the header compression framework and four profiles: uncompressed, RTP, UDP, and ESP (Real-Time Transport Protocol, User Datagram Protocol, Encapsulating Security Payload). RFC3242 specifies a profile with additional link layer assistance called LLA (Link Layer Assisted). A profile for compression of TCP (Transmission Control Protocol) flows is under development within the ROHC working group and SCTP (Stream Control Transmission Protocol) compression is being discussed as potential next candidate. Therefore, the managed objects defined below are structured into three MIB modules: the general ROHC-MIB module and the profile-specific ROHC-UNCOMPRESSED-MIB and ROHC-RTP- MIB modules. This flexible approach allows to support future profiles each by its own profile-specific module.

The ROHC-MIB module defines properties of information on ROHC instances, ROHC channels, ROHC profiles, and ROHC compressor and decompressor contexts. All managed objects in this module are assumed to be shared by all profiles.

The ROHC-UNCOMPRESSED-MIB module extends the ROHC-MIB by managed objects that are specific to the ROHC uncompressed profile 0x0000 defined in RFC3095. The ROHC-RTP-MIB module extends the ROHC-MIB by managed objects that are specific to the three profiles defined in RFC3095 (ROHC RTP profile 0x0001, ROHC UDP profile 0x0002, and ROHC ESP profile 0x0003), and to the ROHC LLA profile 0x0005 defined in RFC3242. An analysis of these profiles showed that they are tightly related and can share most of the managed objects in the ROHC-UNCOMPRESSED-MIB module. Therefore, a joint module for all of them was preferred to individual modules.

The number of managed objects in the ROHC-UNCOMPRESSED-MIB Module and the ROHC-RTP-MIB Module is rather small. They contain context state and context mode, and profile-specific context statistics. It is assumed that MIB modules for future profiles, such as TCP and SCTP, will be similarly small and easy to design.

The ROHC-MIB module

The ROHC-MIB module defines managed objects that are expected to be useful for all current and future ROHC profiles. Objects in the ROHC-MIB module are arranged into four tables: the rohcChannelTable, the rohcInstanceTable, the rohcProfileTable, and the rohcContextTable. The managed objects in the first three tables are rather static (except for provided statistics), while the objects in the rohcContextTable are more dynamic.

All tables are indexed by the IP interface number and by a numeric channel identifier. The channel identifier is used for channels to which compressors and decompressors are attached (called ROHC channels in RFC3759), as well as for dedicated feedback channels (called ROHC feedback channels in RFC3759). Compressor and decompressor instances are further indexed by their type (either compressor or decompressor). Contexts are indexed by the same index as their corresponding instance and their individual context identifier (CID).

rohcChannelTable

The rohcChannelTable lists all channels used by ROHC instances for transferring compressed packets and/or for giving feedback from the decompressor to the compressor. Listed channels are either ROHC channels or feedback channels as defined in RFC3759. The channels are listed per IP interface.

The information per channel in the rohcChannelTable includes

o the channel ID,

o the channel type, either 'notInUse', 'rohc', or

  'dedicatedFeedback',

o the channel for which feedback is provided by this channel (if

  applicable),

o a string for describing the channel, and

o the status of the channel being either 'enabled' or 'disabled'.

rohcInstanceTable

The rohcInstanceTable defines properties of ROHC compressor instances and ROHC decompressor instances.

As described in RFC3759, an instance is associated with exactly one channel and only one instance can be associated with the same channel. Therefore, the same index consisting of ifIndex and rohcChannelID could have been used for both tables. But when accessing the rohcInstanceTable (and the rohcContextTable that shares a part of its index with the rohcInstanceTable) there are many cases where either a compressor contexts or a decompressor contexts are of interest. Therefore, the rohcInstanceType indicating either a compressor or a decompressor was added to the table's index. This allows listing all compressors without accessing any decompressor.

Note that still the combination of ifIndex and rohcChannelID uniquely identifies an instance. It is always possible to directly identify and access the channel corresponding to a given instance.

The set of instance properties in the rochInstanceTable includes

o the vendor of the implementation, version number and description,

o the channels used for compressed packets and for feedback,

o implementation and configuration properties including clock

  resolution, maximum context identifier number (MAX_CID), the
  LARGE_CIDS flag, and the Maximum Reconstructed Reception Unit
  (MRRU),

o the storage time for contexts created by this instance,

o the status of the instance (operational or not).

Optionally, the rohcInstanceTable also contains instance statistics including

o the total number of compressed flows,

o the current number of compressed flows,

o the total number of packets passing this instance

o the total number of static Initialization and Refreshes (IRs)

  passing this instance

o the total number of dynamic Initialization and Refreshes (IR-DYNs)

  passing this instance, and

o the total compression ratio achieved on the channel.

Instances are listed per IP interface.

rohcProfileTable

The rohcProfileTable lists available profiles per instance including information on

o the profile number,

o the vendor and version number, and

o a string describing the profile.

o a flag indicating whether or not using this profile has been

  negotiated with the corresponding (de)compressor.

rohcContextTable

The rohcContextTable lists compressor contexts or decompressor contexts per instance and context identifier (CID). Each row of this table represents a context. If a new context is created, also a new row in this table is created. After expiration or termination of a context, the row will continue to exist until the context's storage time expires or until the CID is re-used. Then the row will be deleted.

For each context, the following attributes are listed:

o the type of context ('compressor' or 'decompressor'), also used as

  part of the table index,

o the CID,

o the state of the CID ('unused', 'active', 'expired', or

  'terminated'), also used as part of the table index,

o the used profile,

o in case of a decompressor: the decompressor depth, and

o the storage time.

Optionally, context statistics is provided including

o activation and deactivation time of the context,

o the number of packets sent or received, respectively,

o the numbers of IRs and IR-DYNs sent or received, respectively,

o the number of feedbacks sent or received, respectively,

o in case of a decompressor context: the numbers of decompressor

  failures and repairs,

o the total compression ratio of all packets passing this context,

o the total compression ratio of all packet headers compressed in

  this context,

o the mean compressed packet size of all packets passing this

  context,

o the mean header size of all compressed headers passing this

  context,

o the compression ratio of the last 16 packets passing this context,

o the compression ratio of the last 16 packet headers compressed in

  this context,

o the mean compressed packet size of the last 16 packets passing

  this context,

o the mean header size of the last 16 compressed headers passing

  this context.

The ROHC-UNCOMPRESSED-MIB module

The ROHC-UNCOMPRESSED-MIB module defines managed objects that are specific to ROHC uncompressed profile (0x0000) specified in RFC3095.

rohcUncmprContextTable

The rohcUncmprContextTable extends the rohcContextTable. It provides information on state and mode of the compressor for profile 0x0000. Optionally, it also provides a counter of ACK feedbacks sent or received by the context, respectively.

The ROHC-RTP-MIB module

The ROHC-RTP-MIB module defines managed objects that are specific to three profiles specified in RFC3095 (ROHC RTP profile 0x0001, ROHC UDP profile 0x0002, and ROHC ESP profile 0x0003) and to the ROHC LLA profile 0x0005 specified in RFC3242. The ROHC-RTP-MIB contains two tables, the rohcRtpContextTable and the rohcRtpPacketSizeTable.

rohcRtpContextTable

The rohcRtpContextTable extends the rohcContextTable. It provides information on context state and context mode for profiles 0x0001 - 0x0003 and 0x0005. For compressor contexts it optionally contains managed object containing the numbers of allowed and used packet sizes. As further option, counters of the numbers of ACKs, NACKs, and SNACKs in this context are specified.

rohcPacketSizeTable

The optional rohcPacketSizeTable lists per compressor context the allowed packet sizes for profiles ROHC RTP, ROHC UDP, ROHC ESP, or the preferred packet sizes for ROHC LLA, respectively. Allowed packet sizes are marked if they are used. For preferred packet sizes, it is indicated whether the preferred size applies to NHP only, to RHP only or to all packets.

Definitions

 ROHC-MIB DEFINITIONS ::= BEGIN
 IMPORTS
  MODULE-IDENTITY, OBJECT-TYPE,
  Unsigned32, Counter32, mib-2
      FROM SNMPv2-SMI                                -- RFC2578
  TEXTUAL-CONVENTION, TruthValue,
  TimeInterval, DateAndTime
      FROM SNMPv2-TC                                 -- RFC2579
  MODULE-COMPLIANCE, OBJECT-GROUP
      FROM SNMPv2-CONF                               -- RFC2580
  SnmpAdminString
      FROM SNMP-FRAMEWORK-MIB                        -- RFC3411
  ifIndex
      FROM IF-MIB;                                   -- RFC2863
 rohcMIB MODULE-IDENTITY
  LAST-UPDATED "200406030000Z"  -- June 3, 2004
  ORGANIZATION "IETF Robust Header Compression Working Group"
  CONTACT-INFO
     "WG charter:
        http://www.ietf.org/html.charters/rohc-charter.html
      Mailing Lists:
        General Discussion: [email protected]
        To Subscribe: [email protected]
        In Body: subscribe your_email_address
      Editor:
        Juergen Quittek
        NEC Europe Ltd.
        Network Laboratories
        Kurfuersten-Anlage 36
        69221 Heidelberg
        Germany
        Tel: +49 6221 90511-15
        EMail: [email protected]"
  DESCRIPTION
      "This MIB module defines a set of basic objects for
       monitoring and configuring robust header compression.
       The module covers information about running instances
       of ROHC (compressors or decompressors) at IP interfaces.
       Information about compressor contexts and decompressor
       contexts has different structure for different profiles.
       Therefore it is not provided by this MIB module, but by
       individual modules for different profiles.
       Copyright (C) The Internet Society (2004). The
       initial version of this MIB module was published
       in RFC 3816. For full legal notices see the RFC
       itself or see:
       http://www.ietf.org/copyrights/ianamib.html"
  REVISION    "200406030000Z"  -- June 3, 2004
  DESCRIPTION "Initial version, published as RFC 3816."
  ::= { mib-2 112 }
 RohcChannelIdentifier ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "d"
  STATUS       current
  DESCRIPTION
      "A number identifying a channel.
       The value of 0 must not be used as identifier
       of an existing channel."
  SYNTAX       Unsigned32 (1..4294967295)
 RohcChannelIdentifierOrZero ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "d"
  STATUS       current
  DESCRIPTION
      "A number identifying a channel.
       The value of 0 is indicates that
       no channel is identified."
  SYNTAX       Unsigned32 (0..4294967295)
 RohcCompressionRatio ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "d"
  STATUS       current
  DESCRIPTION
      "A number indicating a compression ratio over
       a set of bytes.  The value is defined as
       1000 * bytes(compressed) / bytes(original)
       rounded to the next integer value.
       Note that compressed sets of bytes can be larger
       than the corresponding uncompressed ones.
       Therefore, the number can be greater than 1000."
  SYNTAX       Unsigned32
 --
 -- The groups defined within this MIB module:
 --
 rohcObjects       OBJECT IDENTIFIER ::= { rohcMIB 1 }
 rohcConformance   OBJECT IDENTIFIER ::= { rohcMIB 2 }
 --
 -- The ROHC Instance group lists properties of ROHC
 -- instances in the rohcInstanceTable, about the channels used
 -- by the instances in the rohcChanneltable and about the profiles
 -- available at the instances in the rohcProfileTable.
 --
 rohcInstanceObjects       OBJECT IDENTIFIER ::= { rohcObjects 1 }
 --
 -- Channel Table
 --
 -- Listing all channels used for ROHC data channel
 -- and/or as feedback channel.
 --
 rohcChannelTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF RohcChannelEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table lists and describes all ROHC channels
       per interface."
  ::= { rohcInstanceObjects 1 }
 rohcChannelEntry OBJECT-TYPE
  SYNTAX      RohcChannelEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "An entry describing a particular script.  Every script that
       is stored in non-volatile memory is required to appear in
       this script table.
       Note, that the rohcChannelID identifies the channel
       uniquely.  The ifIndex is part of the index of this table
       just in order to allow addressing channels per interface."
  INDEX { ifIndex, rohcChannelID }
  ::= { rohcChannelTable 1 }
 RohcChannelEntry ::= SEQUENCE {
  rohcChannelID               RohcChannelIdentifier,
  rohcChannelType             INTEGER,
  rohcChannelFeedbackFor      RohcChannelIdentifierOrZero,
  rohcChannelDescr            SnmpAdminString,
  rohcChannelStatus           INTEGER
 }
 rohcChannelID OBJECT-TYPE
  SYNTAX      RohcChannelIdentifier
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "The locally arbitrary, but unique identifier associated
       with this channel.  The value is REQUIRED to be unique
       per ROHC MIB implementation independent of the associated
       interface.
       The value is REQUIRED to remain constant at least from one
       re-initialization of the entity's network management system
       to the next re-initialization.  It is RECOMMENDED that the
       value persist across such re-initializations."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcChannelEntry 2 }
 rohcChannelType OBJECT-TYPE
  SYNTAX      INTEGER {
                  notInUse(1),
                  rohc(2),
                  dedicatedFeedback(3)
              }
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Type of usage of the channel.  A channel might be currently
       not in use for ROHC or feedback, it might be in use as
       a ROHC channel carrying packets and optional piggy-backed
       feedback, or it might be used as a dedicated feedback
       channel exclusively carrying feedback."
  ::= { rohcChannelEntry 3 }
 rohcChannelFeedbackFor OBJECT-TYPE
  SYNTAX      RohcChannelIdentifierOrZero
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The index of another channel of this interface for which
       the channel serves as feedback channel.
       If no feedback information is transferred on this channel,
       then the value of this ID is 0.  If the channel type is set
       to notInUse(1), then the value of this object must be 0.
       If the channel type is rohc(2) and the value of this object
       is a valid channel ID, then feedback information is
       piggy-backed on the ROHC channel.  If the channel type is
       dedicatedFeedback(3), then feedback is transferred on this
       channel and the value of this object MUST be different from
       0 and MUST identify an existing ROHC channel."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcChannelEntry 4 }
 rohcChannelDescr OBJECT-TYPE
  SYNTAX      SnmpAdminString
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A textual description of the channel."
  ::= { rohcChannelEntry 5 }
 rohcChannelStatus OBJECT-TYPE
  SYNTAX      INTEGER {
                  enabled(1),
                  disabled(2)
              }
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Status of the channel."
  ::= { rohcChannelEntry 6 }
 --
 -- Instances of ROHC
 --
 -- This table lists properties of running instances of ROHC
 -- compressors and decompressors at the managed node.
 --
 rohcInstanceTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF RohcInstanceEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table lists properties of running instances
       of robust header compressors and decompressors
       at IP interfaces.  It is indexed by interface number,
       the type of instance (compressor or decompressor),
       and the ID of the channel used by the instance as
       ROHC channel.
       Note that the rohcChannelID uniquely identifies an
       instance.  The ifIndex and rohcInstanceType are part
       of the index, because it simplifies accessing instances
       per interface and for addressing either compressors or
       decompressors only."
  ::= { rohcInstanceObjects 2 }
 rohcInstanceEntry OBJECT-TYPE
  SYNTAX      RohcInstanceEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "An entry describing a particular instance
       of a robust header compressor or decompressor."
  INDEX { ifIndex, rohcInstanceType, rohcChannelID }
  ::= { rohcInstanceTable 1 }
 RohcInstanceEntry ::= SEQUENCE {
  rohcInstanceType               INTEGER,
  rohcInstanceFBChannelID        RohcChannelIdentifierOrZero,
  rohcInstanceVendor             OBJECT IDENTIFIER,
  rohcInstanceVersion            SnmpAdminString,
  rohcInstanceDescr              SnmpAdminString,
  rohcInstanceClockRes           Unsigned32,
  rohcInstanceMaxCID             Unsigned32,
  rohcInstanceLargeCIDs          TruthValue,
  rohcInstanceMRRU               Unsigned32,
  rohcInstanceContextStorageTime TimeInterval,
  rohcInstanceStatus             INTEGER,
  rohcInstanceContextsTotal      Counter32,
  rohcInstanceContextsCurrent    Unsigned32,
  rohcInstancePackets            Counter32,
  rohcInstanceIRs                Counter32,
  rohcInstanceIRDYNs             Counter32,
  rohcInstanceFeedbacks          Counter32,
  rohcInstanceCompressionRatio   RohcCompressionRatio
 }
 rohcInstanceType OBJECT-TYPE
  SYNTAX      INTEGER {
                  compressor(1),
                  decompressor(2)
              }
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "Type of the instance of ROHC. It is either a
       compressor instance or a decompressor instance."
  ::= { rohcInstanceEntry 2 }
 rohcInstanceFBChannelID OBJECT-TYPE
  SYNTAX      RohcChannelIdentifierOrZero
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Identifier of the channel used for feedback.
       If no feedback channel is used, the value of
       this object is 0 ."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcInstanceEntry 4 }
 rohcInstanceVendor OBJECT-TYPE
  SYNTAX      OBJECT IDENTIFIER
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "An object identifier that identifies the vendor who
       provides the implementation of robust header description.
       This object identifier SHALL point to the object identifier
       directly below the enterprise object identifier
       {1 3 6 1 4 1} allocated for the vendor.  The value must be
       the object identifier {0 0} if the vendor is not known."
  ::= { rohcInstanceEntry 5 }
 rohcInstanceVersion OBJECT-TYPE
  SYNTAX      SnmpAdminString (SIZE (0..32))
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The version number of the implementation of robust header
       compression.  The zero-length string shall be used if the
       implementation does not have a version number.
       It is suggested that the version number consist of one or
       more decimal numbers separated by dots, where the first
       number is called the major version number."
  ::= { rohcInstanceEntry 6 }
 rohcInstanceDescr OBJECT-TYPE
  SYNTAX      SnmpAdminString
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A textual description of the implementation."
  ::= { rohcInstanceEntry 7 }
 rohcInstanceClockRes OBJECT-TYPE
  SYNTAX      Unsigned32
  UNITS       "milliseconds"
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the system clock resolution in
       units of milliseconds.  A zero (0) value means that there
       is no clock available."
  ::= { rohcInstanceEntry 8 }
 rohcInstanceMaxCID OBJECT-TYPE
  SYNTAX      Unsigned32 (1..16383)
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The highest context ID number to be used by the
       compressor.  Note that this parameter is not coupled to,
       but in effect further constrained by,
       rohcChannelLargeCIDs."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcInstanceEntry 9 }
 rohcInstanceLargeCIDs OBJECT-TYPE
  SYNTAX      TruthValue
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "When retrieved, this boolean object returns false if
       the short CID representation (0 bytes or 1 prefix byte,
       covering CID 0 to 15) is used; it returns true, if the
       embedded CID representation (1 or 2 embedded CID bytes
       covering CID 0 to 16383) is used."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcInstanceEntry 10 }
 rohcInstanceMRRU OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Maximum reconstructed reception unit.  This is the
       size of the largest reconstructed unit in octets that
       the decompressor is expected to reassemble from
       segments (see RFC 3095, Section 5.2.5).  Note that this
       size includes the CRC.  If MRRU is negotiated to be 0,
       no segment headers are allowed on the channel."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcInstanceEntry 11 }
 rohcInstanceContextStorageTime OBJECT-TYPE
  SYNTAX      TimeInterval
  UNITS       "centi-seconds"
  MAX-ACCESS  read-write
  STATUS      current
  DESCRIPTION
      "This object indicates the default maximum amount of time
       information on a context belonging to this instance is kept
       as entry in the rohcContextTable after the context is
       expired or terminated.  The value of this object is used
       to initialize rohcContexStorageTime object when a new
       context is created.
       Changing the value of an rohcInstanceContextStorageTime
       instance does not affect any entry of the rohcContextTable
       created previously.
       ROHC-MIB implementations SHOULD store the set value of this
       object persistently."
  DEFVAL { 360000 }
  ::= { rohcInstanceEntry 12 }
 rohcInstanceStatus OBJECT-TYPE
  SYNTAX      INTEGER {
                  enabled(1),
                  disabled(2)
              }
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Status of the instance of ROHC."
  ::= { rohcInstanceEntry 13 }
 rohcInstanceContextsTotal OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Counter of all contexts created by this instance.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime."
  ::= { rohcInstanceEntry 14 }
 rohcInstanceContextsCurrent OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Number of currently active contexts created by this
       instance."
  ::= { rohcInstanceEntry 15 }
 rohcInstancePackets OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Counter of all packets passing this instance.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime."
  ::= { rohcInstanceEntry 16 }
 rohcInstanceIRs OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all IR packets that are either sent
       or received by this instance.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime."
  REFERENCE
      "RFC 3095, Section 5.7.7.1"
  ::= { rohcInstanceEntry 17 }
 rohcInstanceIRDYNs OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all IR-DYN packets that are either sent
       or received by this instance.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime."
  REFERENCE
      "RFC 3095, Section 5.7.7.2"
  ::= { rohcInstanceEntry 18 }
 rohcInstanceFeedbacks OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all feedbacks that are either sent
       or received by this instance.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime."
  ::= { rohcInstanceEntry 19 }
 rohcInstanceCompressionRatio OBJECT-TYPE
  SYNTAX      RohcCompressionRatio
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the compression ratio so far over all
       packets on the channel served by this instance.  The
       compression is computed over all bytes of the IP packets
       including the IP header but excluding all lower layer
       headers."
  ::= { rohcInstanceEntry 20 }
 --
 -- Profile Table
 --
 rohcProfileTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF RohcProfileEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table lists a set of profiles supported by the
       instance."
  REFERENCE
      "RFC 3095, Section 5.1.1"
  ::= { rohcInstanceObjects 3 }
 rohcProfileEntry OBJECT-TYPE
  SYNTAX      RohcProfileEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "An entry describing a particular profile supported by
       the instance.  It is indexed by the rohcChannelID
       identifying the instance and by the rohcProfile."
  INDEX { rohcChannelID, rohcProfile }
  ::= { rohcProfileTable 1 }
 RohcProfileEntry ::= SEQUENCE {
  rohcProfile            Unsigned32,
  rohcProfileVendor      OBJECT IDENTIFIER,
  rohcProfileVersion     SnmpAdminString,
  rohcProfileDescr       SnmpAdminString,
  rohcProfileNegotiated  TruthValue
 }
 rohcProfile OBJECT-TYPE
  SYNTAX      Unsigned32 (0..65535)
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "Identifier of a profile supported.  For a listing of
       possible profile values, see the IANA registry for
       'RObust Header Compression (ROHC) Profile Identifiers'
       at http://www.iana.org/assignments/rohc-pro-ids"
  ::= { rohcProfileEntry 2 }
 rohcProfileVendor OBJECT-TYPE
  SYNTAX      OBJECT IDENTIFIER
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "An object identifier that identifies the vendor who
       provides the implementation of robust header description.
       This object identifier SHALL point to the object identifier
       directly below the enterprise object identifier
       {1 3 6 1 4 1} allocated for the vendor.  The value must be
       the object identifier {0 0} if the vendor is not known."
  ::= { rohcProfileEntry 3 }
 rohcProfileVersion OBJECT-TYPE
  SYNTAX      SnmpAdminString (SIZE (0..32))
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The version number of the implementation of robust header
       compression.  The zero-length string shall be used if the
       implementation does not have a version number.
       It is suggested that the version number consist of one or
       more decimal numbers separated by dots, where the first
       number is called the major version number."
  ::= { rohcProfileEntry 4 }
 rohcProfileDescr OBJECT-TYPE
  SYNTAX      SnmpAdminString
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A textual description of the implementation."
  ::= { rohcProfileEntry 5 }
 rohcProfileNegotiated OBJECT-TYPE
  SYNTAX      TruthValue
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "When retrieved, this boolean object returns true
       if the profile has been negotiated to be used at
       the instance, i.e., is supported also be the
       corresponding compressor/decompressor."
  ::= { rohcProfileEntry 6 }
 --
 -- Context Table
 --
 rohcContextTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF RohcContextEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table lists and describes all compressor contexts
       per instance."
  ::= { rohcObjects 2 }
 rohcContextEntry OBJECT-TYPE
  SYNTAX      RohcContextEntry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "An entry describing a particular compressor context."
  INDEX {
      rohcChannelID,
      rohcContextCID
  }
  ::= { rohcContextTable 1 }
 RohcContextEntry ::= SEQUENCE {
  rohcContextCID                  Unsigned32,
  rohcContextCIDState             INTEGER,
  rohcContextProfile              Unsigned32,
  rohcContextDecompressorDepth    Unsigned32,
  rohcContextStorageTime          TimeInterval,
  rohcContextActivationTime       DateAndTime,
  rohcContextDeactivationTime     DateAndTime,
  rohcContextPackets              Counter32,
  rohcContextIRs                  Counter32,
  rohcContextIRDYNs               Counter32,
  rohcContextFeedbacks            Counter32,
  rohcContextDecompressorFailures Counter32,
  rohcContextDecompressorRepairs  Counter32,
  rohcContextAllPacketsRatio      RohcCompressionRatio,
  rohcContextAllHeadersRatio      RohcCompressionRatio,
  rohcContextAllPacketsMeanSize   Unsigned32,
  rohcContextAllHeadersMeanSize   Unsigned32,
  rohcContextLastPacketsRatio     RohcCompressionRatio,
  rohcContextLastHeadersRatio     RohcCompressionRatio,
  rohcContextLastPacketsMeanSize  Unsigned32,
  rohcContextLastHeadersMeanSize  Unsigned32
 }
 rohcContextCID OBJECT-TYPE
  SYNTAX      Unsigned32 (0..16383)
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "The context identifier (CID) of this context."
  REFERENCE
      "RFC 3095, Sections 5.1.1 and 5.1.3"
  ::= { rohcContextEntry 2 }
 rohcContextCIDState OBJECT-TYPE
  SYNTAX      INTEGER {
                  unused(1),
                  active(2),
                  expired(3),
                  terminated(4)
              }
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "State of the CID.  When a CID is assigned to a context,
       its state changes from `unused' to `active'.  The active
       context may stop operation due to some explicit
       signalling or after observing no packet for some specified
       time.  In the first case then the CID state changes to
       `terminated', in the latter case it changes to `expired'.
       If the CID is re-used again for another context, the
       state changes back to `active'."
  ::= { rohcContextEntry 3 }
 rohcContextProfile OBJECT-TYPE
  SYNTAX      Unsigned32 (0..65535)
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "Identifier of the profile for this context.
       The profile is identified by its index in the
       rohcProfileTable for this instance.  There MUST exist a
       corresponding entry in the rohcProfileTable using the
       value of rohcContextProfile as second part of the index
       (and using the same rohcChannelID as first part of the
       index)."
  ::= { rohcContextEntry 4 }
 rohcContextDecompressorDepth OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates whether reverse decompression, for
       example as described in RFC 3095, Section 6.1, is used
       on this channel or not, and if used, to what extent.
       Its value is only valid for decompressor contexts, i.e.,
       if rohcInstanceType has the value decompressor(2).  For
       compressor contexts where rohcInstanceType has the value
       compressor(1), the value of this object is irrelevant
       and MUST be set to zero (0).
       The value of the reverse decompression depth indicates
       the maximum number of packets that are buffered, and thus
       possibly be reverse decompressed by the decompressor.
       A zero (0) value means that reverse decompression is not
       used."
  ::= { rohcContextEntry 5 }
 rohcContextStorageTime OBJECT-TYPE
  SYNTAX      TimeInterval
  UNITS       "centi-seconds"
  MAX-ACCESS  read-write
  STATUS      current
  DESCRIPTION
      "The value of this object specifies how long this row
       can exist in the rohcContextTable after the
       rohcContextCIDState switched to expired(3) or
       terminated(4).  This object returns  the remaining time
       that the row may exist before it is aged out.  The object
       is initialized with the value of the  associated
       rohcContextStorageTime object.  After expiration or
       termination of the context, the value of this object ticks
       backwards.  The entry in the rohcContextTable is destroyed
       when the value reaches 0.
       The value of this object may be set in order to increase or
       reduce the remaining time that the row may exist.  Setting
       the value to 0 will destroy this entry as soon as the
       rochContextCIDState has the value expired(3) or
       terminated(4).
       Note that there is no guarantee that the row is stored as
       long as this object indicates.  In case of limited CID
       space, the instance may re-use a CID before the storage
       time of the corresponding row in rohcContextTable reaches
       the value of 0.  In this case the information stored in this
       row is not anymore available."
  ::= { rohcContextEntry 6 }
 rohcContextActivationTime OBJECT-TYPE
  SYNTAX      DateAndTime
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The date and time when the context started to be able to
       compress packets or decompress packets, respectively.
       The value '0000000000000000'H is returned if the context
       has not been activated yet."
  DEFVAL { '0000000000000000'H }
  ::= { rohcContextEntry 7 }
 rohcContextDeactivationTime OBJECT-TYPE
  SYNTAX      DateAndTime
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The date and time when the context stopped being able to
       compress packets or decompress packets, respectively,
       because it expired or was terminated for other reasons.
       The value '0000000000000000'H is returned if the context
       has not been deactivated yet."
  DEFVAL { '0000000000000000'H }
  ::= { rohcContextEntry 8 }
 rohcContextPackets OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all packets passing this context.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  ::= { rohcContextEntry 9 }
 rohcContextIRs OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all IR packets sent or received,
       respectively, by this context.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  REFERENCE
      "RFC 3095, Section 5.7.7.1"
  ::= { rohcContextEntry 10 }
 rohcContextIRDYNs OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all IR-DYN packets sent or received,
       respectively, by this context.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  REFERENCE
      "RFC 3095, Section 5.7.7.2"
  ::= { rohcContextEntry 11 }
 rohcContextFeedbacks OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all feedbacks sent or received,
       respectively, by this context.
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  ::= { rohcContextEntry 12 }
 rohcContextDecompressorFailures OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all decompressor failures so far in this
       context. The number is only valid for decompressor
       contexts, i.e., if rohcInstanceType has the value
       decompressor(2).
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  ::= { rohcContextEntry 13 }
 rohcContextDecompressorRepairs OBJECT-TYPE
  SYNTAX      Counter32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The number of all context repairs so far in this
       context.  The number is only valid for decompressor
       contexts, i.e., if rohcInstanceType has the value
       decompressor(2).
       Discontinuities in the value of this counter can
       occur at re-initialization of the management
       system, and at other times as indicated by the
       value of ifCounterDiscontinuityTime.  For checking
       ifCounterDiscontinuityTime, the interface index is
       required.  It can be determined by reading the
       rohcChannelTable."
  ::= { rohcContextEntry 14 }
 rohcContextAllPacketsRatio OBJECT-TYPE
  SYNTAX      RohcCompressionRatio
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the compression ratio so far over all
       packets passing this context.  The compression is computed
       over all bytes of the IP packets including the IP header
       but excluding all lower layer headers."
  ::= { rohcContextEntry 15 }
 rohcContextAllHeadersRatio OBJECT-TYPE
  SYNTAX      RohcCompressionRatio
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the compression ratio so far over all
       packet headers passing this context.  The compression is
       computed over all bytes of all headers that are subject to
       compression for the used profile."
  ::= { rohcContextEntry 16 }
 rohcContextAllPacketsMeanSize OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the mean compressed packet size
       of all packets passing this context.  The packet size
       includes the IP header and payload but excludes all lower
       layer headers.  The mean value is given in byte rounded
       to the next integer value."
  ::= { rohcContextEntry 17 }
 rohcContextAllHeadersMeanSize OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the mean compressed packet header size
       of all packets passing this context.  The packet header size
       is the sum of the size of all headers of a packet that are
       subject to compression for the used profile.  The mean value
       is given in byte rounded to the next integer value."
  ::= { rohcContextEntry 18 }
 rohcContextLastPacketsRatio OBJECT-TYPE
  SYNTAX      RohcCompressionRatio
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the compression ratio
       concerning the last 16 packets passing this context
       or concerning all packets passing this context
       if they are less than 16, so far.  The compression is
       computed over all bytes of the IP packets including the IP
       header but excluding all lower layer headers."
  ::= { rohcContextEntry 19 }
 rohcContextLastHeadersRatio OBJECT-TYPE
  SYNTAX      RohcCompressionRatio
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the compression ratio concerning the
       headers of the last 16 packets passing this context or
       concerning the headers of all packets passing this context
       if they are less than 16, so far.  The compression is
       computed over all bytes of all headers that are subject to
       compression for the used profile."
  ::= { rohcContextEntry 20 }
 rohcContextLastPacketsMeanSize OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the mean compressed packet size
       concerning the last 16 packets passing this context or
       concerning all packets passing this context if they are
       less than 16, so far.  The packet size includes the IP
       header and payload but excludes all lower layer headers.
       The mean value is given in byte rounded to the next
       integer value."
  ::= { rohcContextEntry 21 }
 rohcContextLastHeadersMeanSize OBJECT-TYPE
  SYNTAX      Unsigned32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "This object indicates the mean compressed packet header size
       concerning the last 16 packets passing this context or
       concerning all packets passing this context if they are
       less than 16, so far.  The packet header size is the sum of
       the size of all headers of a packet that are subject to
       compression for the used profile.  The mean value is given
       in byte rounded to the next integer value."
  ::= { rohcContextEntry 22 }
 --
 -- conformance information
 --
 rohcCompliances OBJECT IDENTIFIER ::= { rohcConformance 1 }
 rohcGroups      OBJECT IDENTIFIER ::= { rohcConformance 2 }
 --
 -- compliance statements
 --
 rohcCompliance MODULE-COMPLIANCE
  STATUS      current
  DESCRIPTION
      "The compliance statement for SNMP entities that implement
       the ROHC-MIB.
       Note that compliance with this compliance
       statement requires compliance with the
       ifCompliance3 MODULE-COMPLIANCE statement of the
       IF-MIB (RFC2863)."
  MODULE      -- this module
  MANDATORY-GROUPS {
          rohcInstanceGroup, rohcContextGroup
  }
  GROUP   rohcStatisticsGroup
  DESCRIPTION
     "A compliant implementation does not have to implement
      the rohcStatisticsGroup."
  GROUP   rohcTimerGroup
  DESCRIPTION
     "A compliant implementation does not have to implement
      the rohcTimerGroup."
  OBJECT  rohcInstanceContextStorageTime
  MIN-ACCESS  read-only
  DESCRIPTION
      "A compliant implementation does not have to support changing
       the value of object rohcInstanceContextStorageTime."
  OBJECT  rohcContextStorageTime
  MIN-ACCESS  read-only
  DESCRIPTION
      "A compliant implementation does not have to support changing
       the value of object rohcContextStorageTime."
  GROUP   rohcContextStatisticsGroup
  DESCRIPTION
     "A compliant implementation does not have to implement
      the rohcContextStatisticsGroup."
  ::= { rohcCompliances 1 }
 rohcInstanceGroup OBJECT-GROUP
  OBJECTS {
      rohcChannelType,
      rohcChannelFeedbackFor,
      rohcChannelDescr,
      rohcChannelStatus,
      rohcInstanceFBChannelID,
      rohcInstanceVendor,
      rohcInstanceVersion,
      rohcInstanceDescr,
      rohcInstanceClockRes,
      rohcInstanceMaxCID,
      rohcInstanceLargeCIDs,
      rohcInstanceMRRU,
      rohcInstanceStatus,
      rohcProfileVendor,
      rohcProfileVersion,
      rohcProfileDescr,
      rohcProfileNegotiated
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects providing information about
       ROHC instances, used channels and available profiles."
  ::= { rohcGroups 2 }
 rohcStatisticsGroup OBJECT-GROUP
  OBJECTS {
      rohcInstanceContextsTotal,
      rohcInstanceContextsCurrent,
      rohcInstancePackets,
      rohcInstanceIRs,
      rohcInstanceIRDYNs,
      rohcInstanceFeedbacks,
      rohcInstanceCompressionRatio
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects providing ROHC statistics."
  ::= { rohcGroups 4 }
 rohcContextGroup OBJECT-GROUP
  OBJECTS {
      rohcContextCIDState,
      rohcContextProfile,
      rohcContextDecompressorDepth
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects providing information about
       ROHC compressor contexts and decompressor contexts."
  ::= { rohcGroups 5 }
 rohcTimerGroup OBJECT-GROUP
  OBJECTS {
      rohcInstanceContextStorageTime,
      rohcContextStorageTime,
      rohcContextActivationTime,
      rohcContextDeactivationTime
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects providing statistical information
       about ROHC compressor contexts and decompressor contexts."
  ::= { rohcGroups 6 }
 rohcContextStatisticsGroup OBJECT-GROUP
  OBJECTS {
      rohcContextPackets,
      rohcContextIRs,
      rohcContextIRDYNs,
      rohcContextFeedbacks,
      rohcContextDecompressorFailures,
      rohcContextDecompressorRepairs,
      rohcContextAllPacketsRatio,
      rohcContextAllHeadersRatio,
      rohcContextAllPacketsMeanSize,
      rohcContextAllHeadersMeanSize,
      rohcContextLastPacketsRatio,
      rohcContextLastHeadersRatio,
      rohcContextLastPacketsMeanSize,
      rohcContextLastHeadersMeanSize
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects providing statistical information
       about ROHC compressor contexts and decompressor contexts."
  ::= { rohcGroups 7 }
 END

ROHC-UNCOMPRESSED-MIB DEFINITIONS ::= BEGIN

IMPORTS

   MODULE-IDENTITY, OBJECT-TYPE, Counter32, mib-2
       FROM SNMPv2-SMI                               -- RFC2578
   MODULE-COMPLIANCE, OBJECT-GROUP
       FROM SNMPv2-CONF                              -- RFC2580
   rohcChannelID, rohcContextCID
       FROM ROHC-MIB;

rohcUncmprMIB MODULE-IDENTITY

   LAST-UPDATED "200406030000Z"  -- June 3, 2004
   ORGANIZATION "IETF Robust Header Compression Working Group"
   CONTACT-INFO
      "WG charter:
         http://www.ietf.org/html.charters/rohc-charter.html
       Mailing Lists:
         General Discussion: [email protected]
         To Subscribe: [email protected]
         In Body: subscribe your_email_address
       Editor:
         Juergen Quittek
         NEC Europe Ltd.
         Network Laboratories
         Kurfuersten-Anlage 36
         69221 Heidelberg
         Germany
         Tel: +49 6221 90511-15
         EMail: [email protected]"
   DESCRIPTION
       "This MIB module defines a set of objects for monitoring
        and configuring RObust Header Compression (ROHC).
        The objects are specific to ROHC uncompressed
        (profile 0x0000).
        Copyright (C) The Internet Society (2004). The
        initial version of this MIB module was published
        in RFC 3816. For full legal notices see the RFC
        itself or see:
        http://www.ietf.org/copyrights/ianamib.html"
   REVISION    "200406030000Z"  -- June 3, 2004
   DESCRIPTION "Initial version, published as RFC 3816."
   ::= { mib-2 113 }

-- -- The groups defined within this MIB module: --

rohcUncmprObjects OBJECT IDENTIFIER ::= { rohcUncmprMIB 1 } rohcUncmprConformance OBJECT IDENTIFIER ::= { rohcUncmprMIB 2 }

-- -- Context Table -- -- The rohcUncmprContextTable lists all contexts per interface

-- and instance. It extends the rohcContextTable. --

rohcUncmprContextTable OBJECT-TYPE

   SYNTAX      SEQUENCE OF RohcUncmprContextEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "This table lists and describes ROHC uncompressed profile
        specific properties of compressor contexts and
        decompressor contexts.  It extends the rohcContextTable
        of the ROHC-MIB module."
   ::= { rohcUncmprObjects 1 }

rohcUncmprContextEntry OBJECT-TYPE

   SYNTAX      RohcUncmprContextEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "An entry describing a particular context."
   INDEX {
       rohcChannelID,
       rohcContextCID
   }
   ::= { rohcUncmprContextTable 1 }

RohcUncmprContextEntry ::= SEQUENCE {

   rohcUncmprContextState         INTEGER,
   rohcUncmprContextMode          INTEGER,
   rohcUncmprContextACKs          Counter32

}

rohcUncmprContextState OBJECT-TYPE

   SYNTAX      INTEGER {
                   initAndRefresh(1),
                   normal(2),
                   noContext(3),
                   fullContext(4)
               }
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "State of the context. States initAndRefresh(1) and normal(2)
        are states of compressor contexts, states noContext(3)
        and fullContext(4) are states of decompressor contexts."
   REFERENCE
       "RFC 3095, Section 5.10.3"
   ::= { rohcUncmprContextEntry 3 }

rohcUncmprContextMode OBJECT-TYPE

   SYNTAX      INTEGER {
                   unidirectional(1),
                   bidirectional(2)
               }
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "Mode of the context."
   REFERENCE
       "RFC 3095, Section 5.10.3"
   ::= { rohcUncmprContextEntry 4 }

rohcUncmprContextACKs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The number of all positive feedbacks (ACK) sent or
        received in this context, respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB."
   REFERENCE
       "RFC 3095, Section 5.2.1"
   ::= { rohcUncmprContextEntry 5 }

-- -- conformance information --

rohcUncmprCompliances OBJECT IDENTIFIER

   ::= { rohcUncmprConformance 1 }

rohcUncmprGroups OBJECT IDENTIFIER

   ::= { rohcUncmprConformance 2 }

-- -- compliance statements --

rohcUncmprCompliance MODULE-COMPLIANCE

   STATUS      current
   DESCRIPTION
       "The compliance statement for SNMP entities that implement
        the ROHC-UNCOMPRESSED-MIB.
        Note that compliance with this compliance
        statement requires compliance with the
        rohcCompliance MODULE-COMPLIANCE statement of the
        ROHC-MIB and with the ifCompliance3 MODULE-COMPLIANCE
        statement of the IF-MIB (RFC2863)."
   MODULE      -- this module
   MANDATORY-GROUPS {
           rohcUncmprContextGroup
   }
   GROUP   rohcUncmprStatisticsGroup
   DESCRIPTION
      "A compliant implementation does not have to implement
       the rohcUncmprStatisticsGroup."
   ::= { rohcUncmprCompliances 1 }

rohcUncmprContextGroup OBJECT-GROUP

   OBJECTS {
       rohcUncmprContextState,
       rohcUncmprContextMode
   }
   STATUS      current
   DESCRIPTION
       "A collection of objects providing information about
        ROHC uncompressed compressors and decompressors."
   ::= { rohcUncmprGroups 1 }

rohcUncmprStatisticsGroup OBJECT-GROUP

   OBJECTS {
       rohcUncmprContextACKs
   }
   STATUS      current
   DESCRIPTION
       "An object providing context statistics."
   ::= { rohcUncmprGroups 2 }

END

ROHC-RTP-MIB DEFINITIONS ::= BEGIN

IMPORTS

   MODULE-IDENTITY, OBJECT-TYPE,
   Unsigned32, Counter32, mib-2
       FROM SNMPv2-SMI                               -- RFC2578
   TruthValue
       FROM SNMPv2-TC                                -- RFC2579
   MODULE-COMPLIANCE, OBJECT-GROUP
       FROM SNMPv2-CONF                              -- RFC2580
   rohcChannelID, rohcContextCID
       FROM ROHC-MIB;                                -- RFC3816

rohcRtpMIB MODULE-IDENTITY

   LAST-UPDATED "200406030000Z"  -- June 3, 2004
   ORGANIZATION "IETF Robust Header Compression Working Group"
   CONTACT-INFO
      "WG charter:
         http://www.ietf.org/html.charters/rohc-charter.html
       Mailing Lists:
         General Discussion: [email protected]
         To Subscribe: [email protected]
         In Body: subscribe your_email_address
       Editor:
         Juergen Quittek
         NEC Europe Ltd.
         Network Laboratories
         Kurfuersten-Anlage 36
         69221 Heidelberg
         Germany
         Tel: +49 6221 90511-15
         EMail: [email protected]"
   DESCRIPTION
       "This MIB module defines a set of objects for monitoring
        and configuring RObust Header Compression (ROHC).
        The objects are specific to ROHC RTP (profile 0x0001),
        ROHC UDP (profile 0x0002), and ROHC ESP (profile 0x0003)
        defined in RFC 3095 and for the ROHC LLA profile (profile
        0x0005) defined in RFC 3242.
        Copyright (C) The Internet Society (2004). The
        initial version of this MIB module was published
        in RFC 3816. For full legal notices see the RFC
        itself or see:
        http://www.ietf.org/copyrights/ianamib.html"
   REVISION    "200406030000Z"  -- June 3, 2004
   DESCRIPTION "Initial version, published as RFC 3816."
   ::= { mib-2 114 }

-- -- The groups defined within this MIB module: --

rohcRtpObjects OBJECT IDENTIFIER ::= { rohcRtpMIB 1 } rohcRtpConformance OBJECT IDENTIFIER ::= { rohcRtpMIB 2 }

-- -- Context Table -- -- The rohcRtpContextTable lists all contexts per interface -- and instance. It extends the rohcContextTable. --

rohcRtpContextTable OBJECT-TYPE

   SYNTAX      SEQUENCE OF RohcRtpContextEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "This table lists and describes RTP profile specific
        properties of compressor contexts and decompressor
        contexts.  It extends the rohcContextTable of the
        ROHC-MIB module."
   ::= { rohcRtpObjects 1 }

rohcRtpContextEntry OBJECT-TYPE

   SYNTAX      RohcRtpContextEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "An entry describing a particular context."
   INDEX {
       rohcChannelID,
       rohcContextCID
   }
   ::= { rohcRtpContextTable 1 }

RohcRtpContextEntry ::= SEQUENCE {

   rohcRtpContextState             INTEGER,
   rohcRtpContextMode              INTEGER,
   rohcRtpContextAlwaysPad         TruthValue,
   rohcRtpContextLargePktsAllowed  TruthValue,
   rohcRtpContextVerifyPeriod      Unsigned32,
   rohcRtpContextSizesAllowed      Unsigned32,
   rohcRtpContextSizesUsed         Unsigned32,
   rohcRtpContextACKs              Counter32,
   rohcRtpContextNACKs             Counter32,
   rohcRtpContextSNACKs            Counter32,
   rohcRtpContextNHPs              Counter32,
   rohcRtpContextCSPs              Counter32,
   rohcRtpContextCCPs              Counter32,
   rohcRtpContextPktsLostPhysical  Counter32,
   rohcRtpContextPktsLostPreLink   Counter32

}

rohcRtpContextState OBJECT-TYPE

   SYNTAX      INTEGER {
                   initAndRefresh(1),
                   firstOrder(2),
                   secondOrder(3),
                   noContext(4),
                   staticContext(5),
                   fullContext(6)
               }
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "State of the context as defined in RFC 3095.  States
        initAndRefresh(1), firstOrder(2), and secondOrder(3)
        are states of compressor contexts, states noContext(4),
        staticContext(5) and fullContext(6) are states of
        decompressor contexts."
   REFERENCE
       "RFC 3095"
   ::= { rohcRtpContextEntry 3 }

rohcRtpContextMode OBJECT-TYPE

   SYNTAX      INTEGER {
                   unidirectional(1),
                   optimistic(2),
                   reliable(3)
               }
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "Mode of the context."
   REFERENCE
       "RFC 3095, Section 4.4"
   ::= { rohcRtpContextEntry 4 }

rohcRtpContextAlwaysPad OBJECT-TYPE

   SYNTAX      TruthValue
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "Boolean, only applicable to compressor contexts using the
        LLA profile.  If its value is true, the compressor must
        pad every RHP packet with a minimum of one octet ROHC
        padding.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 5.1.1"
   DEFVAL { false }
   ::= { rohcRtpContextEntry 5 }

rohcRtpContextLargePktsAllowed OBJECT-TYPE

   SYNTAX      TruthValue
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "Boolean, only applicable to compressor contexts using the
        LLA profile.  It specifies how to handle packets that do
        not fit any of the preferred packet sizes specified.  If
        its value is true, the compressor must deliver the larger
        packet as-is and must not use segmentation.  If it is set
        to false, the ROHC segmentation scheme must be used to
        split the packet into two or more segments, and each
        segment must further be padded to fit one of the preferred
        packet sizes.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 5.1.1"
   DEFVAL { true }
   ::= { rohcRtpContextEntry 6 }

rohcRtpContextVerifyPeriod OBJECT-TYPE

   SYNTAX      Unsigned32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to compressor contexts
        using the LLA profile.  It specifies the minimum frequency
        with which a packet validating the context must be sent.
        This tells the compressor that a packet containing a CRC
        field must be sent at least once every N packets, where N
        is the value of the object.  A value of 0 indicates that
        periodical verifications are disabled.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 5.1.1"
   DEFVAL { 0 }
   ::= { rohcRtpContextEntry 7 }

rohcRtpContextSizesAllowed OBJECT-TYPE

   SYNTAX      Unsigned32 (1..4294967295)
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The value of this object is only valid for decompressor
        contexts, i.e., if rohcInstanceType of the corresponding
        rohcContextEntry has the value decompressor(2).  For
        compressor contexts where rohcInstanceType has the value
        compressor(1), this object MUST NOT be instantiated.
        This object contains the number of different packet sizes
        that may be used in the context."
   REFERENCE
       "RFC 3095, Section 6.3.1"
   ::= { rohcRtpContextEntry 8 }

rohcRtpContextSizesUsed OBJECT-TYPE

   SYNTAX      Unsigned32 (1..4294967295)
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The value of this object is only valid for decompressor
        contexts, i.e., if rohcInstanceType of the corresponding
        rohcContextEntry has the value decompressor(2).  For
        compressor contexts where rohcInstanceType has the value
        compressor(1), this object MUST NOT be instantiated.
        This object contains the number of different packet sizes
        that are used in the context."
   REFERENCE
       "RFC 3095, Section 6.3.1"
   ::= { rohcRtpContextEntry 9 }

rohcRtpContextACKs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The number of all positive feedbacks (ACK) sent or
        received in this context, respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB."
   REFERENCE
       "RFC 3095, Section 5.2.1."
   ::= { rohcRtpContextEntry 10 }

rohcRtpContextNACKs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The number of all dynamic negative feedbacks (ACK) sent
        or received in this context, respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB."
   REFERENCE
       "RFC 3095, Section 5.2.1."
   ::= { rohcRtpContextEntry 11 }

rohcRtpContextSNACKs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "The number of all static negative feedbacks (ACK) sent
        or received in this context, respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB."
   REFERENCE
       "RFC 3095, Section 5.2.1."
   ::= { rohcRtpContextEntry 12 }

rohcRtpContextNHPs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to contexts using the
        LLA profile.  It contains the number of all no-header
        packets (NHP) sent or received in this context,
        respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 4.1.1."
   ::= { rohcRtpContextEntry 13 }

rohcRtpContextCSPs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to contexts using the
        LLA profile.  It contains the number of all context
        synchronization packets (CSP) sent or received in this
        context, respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 4.1.2."
   ::= { rohcRtpContextEntry 14 }

rohcRtpContextCCPs OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to contexts using the
        LLA profile.  It contains the number of all context check
        packets (CCP) sent or received in this context,
        respectively.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 4.1.3."
   ::= { rohcRtpContextEntry 15 }

rohcRtpContextPktsLostPhysical OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to decompressor contexts
        using the LLA profile.  It contains the number of physical
        packet losses on the link between compressor and
        decompressor, that have been indicated to the decompressor.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 5.1.2."
   ::= { rohcRtpContextEntry 16 }

rohcRtpContextPktsLostPreLink OBJECT-TYPE

   SYNTAX      Counter32
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to decompressor contexts
        using the LLA profile.  It contains the number of pre-link
        packet losses on the link between compressor and
        decompressor, that have been indicated to the decompressor.
        Discontinuities in the value of this counter can
        occur at re-initialization of the management
        system, and at other times as indicated by the
        value of ifCounterDiscontinuityTime.  For checking
        ifCounterDiscontinuityTime, the interface index is
        required.  It can be determined by reading the
        rohcChannelTable of the ROHC-MIB.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
       "RFC 3242, Section 5.1.2."
   ::= { rohcRtpContextEntry 17 }

-- -- Packet Sizes Table -- -- The rohcPacketSizeTable lists allowed, preferred, and used -- packet sizes per compressor context.

rohcRtpPacketSizeTable OBJECT-TYPE

   SYNTAX      SEQUENCE OF RohcRtpPacketSizeEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "This table lists all allowed, preferred, and used packet
        sizes per compressor context and channel.
        Note, that the sizes table represents implementation
        parameters that are suggested by RFC 3095 and/or RFC 3242,
        but that are not mandatory."
   ::= { rohcRtpObjects 2 }

rohcRtpPacketSizeEntry OBJECT-TYPE

   SYNTAX      RohcRtpPacketSizeEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "An entry of a particular packet size."
   INDEX {
       rohcChannelID,
       rohcContextCID,
       rohcRtpPacketSize
   }
   ::= { rohcRtpPacketSizeTable 1 }

RohcRtpPacketSizeEntry ::= SEQUENCE {

   rohcRtpPacketSize                Unsigned32,
   rohcRtpPacketSizePreferred       TruthValue,
   rohcRtpPacketSizeUsed            TruthValue,
   rohcRtpPacketSizeRestrictedType  INTEGER

}

rohcRtpPacketSize OBJECT-TYPE

   SYNTAX      Unsigned32 (1..4294967295)
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
       "A packet size used as index."
   ::= { rohcRtpPacketSizeEntry 3 }

rohcRtpPacketSizePreferred OBJECT-TYPE

   SYNTAX      TruthValue
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to compressor contexts
        using the LLA profile.  When retrieved, it will have
        the value true(1) if the packet size is preferred.
        Otherwise, its value will be false(2).
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
        "RFC 3242, Section 5.1.1"
   ::= { rohcRtpPacketSizeEntry 4 }

rohcRtpPacketSizeUsed OBJECT-TYPE

   SYNTAX      TruthValue
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to compressor contexts
        using the UDP, RTP, or ESP profile.  When retrieved,
        it will have the value true(1) if the packet size is
        used.  Otherwise, its value will be false(2).
        The value of this object is only valid for UDP, RTP,
        and ESP profiles, i.e., if the corresponding rohcProfile
        has a value of either 0x0001, 0x0002 or 0x0003.  If
        the corresponding rohcProfile has a value other than
        0x0001, 0x0002 or 0x0003, then this object MUST NOT be
        instantiated."
   REFERENCE
        "RFC 3095, Section 6.3.1"
   ::= { rohcRtpPacketSizeEntry 5 }

rohcRtpPacketSizeRestrictedType OBJECT-TYPE

   SYNTAX      INTEGER {
                   nhpOnly(1),
                   rhpOnly(2),
                   noRestrictions(3)
               }
   MAX-ACCESS  read-only
   STATUS      current
   DESCRIPTION
       "This object is only applicable to preferred packet
        sizes of compressor contexts using the LLA profile.
        When retrieved, it will indicate whether the packet
        size is preferred for NHP only, for RHP only, or
        for both of them.
        The value of this object is only valid for LLA profiles,
        i.e., if the corresponding rohcProfile has a value of
        0x0005.  If the corresponding rohcProfile has a value
        other than 0x0005, then this object MUST NOT be
        instantiated."
   REFERENCE
        "RFC 3242, Section 5.1.1"
   ::= { rohcRtpPacketSizeEntry 6 }

-- -- conformance information --

rohcRtpCompliances OBJECT IDENTIFIER ::= { rohcRtpConformance 1 } rohcRtpGroups OBJECT IDENTIFIER ::= { rohcRtpConformance 2 }

-- -- compliance statements --

rohcRtpCompliance MODULE-COMPLIANCE

   STATUS      current
   DESCRIPTION
       "The compliance statement for SNMP entities that implement
        the ROHC-RTP-MIB.
        Note that compliance with this compliance
        statement requires compliance with the
        rohcCompliance MODULE-COMPLIANCE statement of the
        ROHC-MIB and with the ifCompliance3 MODULE-COMPLIANCE
        statement of the IF-MIB (RFC2863)."
   MODULE      -- this module
   MANDATORY-GROUPS {
           rohcRtpContextGroup
   }
   GROUP   rohcRtpPacketSizesGroup
   DESCRIPTION
      "A compliant implementation does not have to implement
       the rohcRtpPacketSizesGroup."
   GROUP   rohcRtpStatisticsGroup
   DESCRIPTION
      "A compliant implementation does not have to implement
       the rohcRtpStatisticsGroup."
   ::= { rohcRtpCompliances 1 }

rohcRtpContextGroup OBJECT-GROUP

   OBJECTS {
       rohcRtpContextState,
       rohcRtpContextMode,
       rohcRtpContextAlwaysPad,
       rohcRtpContextLargePktsAllowed,
       rohcRtpContextVerifyPeriod
   }
   STATUS      current
   DESCRIPTION
       "A collection of objects providing information about
        ROHC RTP compressors and decompressors."
   ::= { rohcRtpGroups 1 }

rohcRtpPacketSizesGroup OBJECT-GROUP

   OBJECTS {
       rohcRtpContextSizesAllowed,
       rohcRtpContextSizesUsed,
       rohcRtpPacketSizePreferred,
       rohcRtpPacketSizeUsed,
       rohcRtpPacketSizeRestrictedType
   }
   STATUS      current
   DESCRIPTION
       "A collection of objects providing information about
        allowed and used packet sizes at a ROHC RTP compressor."
   ::= { rohcRtpGroups 2 }

rohcRtpStatisticsGroup OBJECT-GROUP

   OBJECTS {
       rohcRtpContextACKs,
       rohcRtpContextNACKs,
       rohcRtpContextSNACKs,
       rohcRtpContextNHPs,
       rohcRtpContextCSPs,
       rohcRtpContextCCPs,
       rohcRtpContextPktsLostPhysical,
       rohcRtpContextPktsLostPreLink
   }
   STATUS      current
   DESCRIPTION
       "A collection of objects providing ROHC compressor and
        decompressor statistics."
   ::= { rohcRtpGroups 3 }

END

Security Considerations

The managed objects defined by the ROHC-MIB module, the ROHC- UNCOMPRESSED-MIB module and the ROHC-RTP-MIB module do not have a MAX-ACCESS value of read-write and/or read-create except rohcInstanceContextStorageTime and rohcContextStorageTime, both of which have a MAX-ACCESS value of read-write. These objects determine how long context information is stored after its termination. Unauthorized access to these objects can have one of two negative effects. If they are set to a value lower than required, e.g., to zero, then context information about past contexts might get lost. If they are set to a very high value, then context information will not be deleted and memory consumption of the agent implementation might become very high. However, unauthorized access to these objects cannot cause harm to existing ROHC connections nor can it allow manipulation of running instances of ROHC in a malicious way.

Another security issue is unauthorized access to readable objects in the MIB modules for getting information about existing communication sessions. It is thus important to control even GET and/or NOTIFY access to these objects and possibly to even encrypt the values of these objects when sending them over the network via SNMP. However, the only information that might be disclosed is the use of channels. Users and their addresses are not visible in the MIB. This information can only be mis-used in conjunction with the mis-use of further information.

SNMP versions prior to SNMPv3 did not include adequate security. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB module.

It is RECOMMENDED that implementers consider the security features as provided by the SNMPv3 framework (see RFC3410, section 8), including full support for the SNMPv3 cryptographic mechanisms (for authentication and privacy).

Further, deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to enable cryptographic security. It is then a customer/operator responsibility to ensure that the SNMP entity giving access to an instance of this MIB module is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them.

Acknowledgements

Many thanks to Lars-Erik Jonsson and Mark West for their guidance through the ROHC world and to Ghyslain Pelletier for explaining how the ROHC LLA profile works. Further thanks to Frank Strauss for his advice on tricky SMI issues. Special thanks to Mike Heard who acted as MIB doctor. He studied every tiny detail, raised a long list of issues and helped to significantly improve this document.

References

Normative References

RFC2578 McCloghrie, K., Perkins, D., and J. Schoenwaelder,

           "Structure of Management Information Version 2 (SMIv2)",
           STD 58, RFC 2578, April 1999.

RFC2579 McCloghrie, K., Perkins, D., and J. Schoenwaelder,

           "Textual Conventions for SMIv2", STD 58, RFC 2579, April
           1999.

RFC2580 McCloghrie, K., Perkins, D., and J. Schoenwaelder,

           "Conformance Statements for SMIv2", STD 58, RFC 2580,
           April 1999.

RFC2863 McCloghrie, K. and F. Kastenholz, "The Interfaces Group

           MIB", RFC 2863, June 2000.

RFC3095 Bormann, C., Burmeister, C., Degermark, M., Fukushima,

           H., Hannu, H., Jonsson, L., Hakenberg, R., Koren, T., Le,
           K., Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K.,
           Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header
           Compression (ROHC): Framework and four profiles: RTP,
           UDP, ESP, and uncompressed", RFC 3095, July 2001.

RFC3242 Jonsson, L. and G. Pelletier, "RObust Header Compression

           (ROHC): A Link-Layer Assisted Profile for IP/UDP/RTP",
           RFC 3242, April 2002.

RFC3411 Harrington, D., Presuhn, R., and B. Wijnen, "An

           Architecture for Describing Simple Network Management
           Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
           December 2002.

RFC3759 Jonsson, L., "RObust Header Compression (ROHC):

           Terminology and Channel Mapping Examples", RFC 3759,
           April 2004.

Informative References

RFC3410 Case, J., Mundy, R., Partain, D., and B. Stewart,

           "Introduction and Applicability Statements for Internet-
           Standard Management Framework", RFC 3410, December 2002.

Authors' Addresses

Juergen Quittek NEC Europe Ltd. Network Laboratories Kurfuersten-Anlage 36 69115 Heidelberg Germany

Phone: +49 6221 90511-15 EMail: [email protected]

Martin Stiemerling NEC Europe Ltd. Network Laboratories Kurfuersten-Anlage 36 69115 Heidelberg Germany

Phone: +49 6221 90511-13 EMail: [email protected]

Hannes Hartenstein University of Karlsruhe Computing Center and Institute of Telematics 76128 Karlsruhe Germany

Phone: +49 721 608 8104 EMail: [email protected]

10. Full Copyright Statement

Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.

This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- [email protected].

Acknowledgement

Funding for the RFC Editor function is currently provided by the Internet Society.