rfc2959.txt

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Network Working Group                                        M. Baugher
Request for Comments: 2959                                    B. Strahm
Category: Standards Track                                   Intel Corp.
                                                            I. Suconick
                                                      VideoServer Corp.
                                                           October 2000


                      Real-Time Transport Protocol
                      Management Information Base

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 (2000).  All Rights Reserved.

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 defines objects for managing Real-Time Transport
   Protocol (RTP) systems (RFC1889).

Table of Contents

   1. The Network Management Framework .............................  2
   2. Overview .....................................................  3
   2.1 Components ..................................................  3
   2.2 Applicability of the MIB to RTP System Implementations ......  4
   2.3 The Structure of the RTP MIB ................................  4
   3 Definitions ...................................................  5
   4. Security Considerations ...................................... 26
   5. Acknowledgements ............................................. 27
   6. Intellectual Property ........................................ 27
   7. References ................................................... 28
   8. Authors' Addresses ........................................... 30
   9. Full Copyright Statement ..................................... 31







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RFC 2959                        RTP MIB                     October 2000


1.  The SNMP Management Framework

   The SNMP Management Framework presently consists of five major
   components:

      o  An overall architecture, described in RFC 2571 [RFC2571].

      o  Mechanisms for describing and naming objects and events for the
         purpose of management.  The first version of this Structure of
         Management Information (SMI) is called SMIv1 and described in
         STD 16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC
         1215 [RFC1215].  The second version, called SMIv2, is described
         in STD 58, RFC 2578 [RFC2578], RFC 2579 [RFC2579] and RFC 2580
         [RFC2580].

      o  Message protocols for transferring management information.  The
         first version of the SNMP message protocol is called SNMPv1 and
         described in STD 15, RFC 1157 [RFC1157].  A second version of
         the SNMP message protocol, which is not an Internet standards
         track protocol, is called SNMPv2c and described in RFC 1901
         [RFC1901] and RFC 1906 [RFC1906].  The third version of the
         message protocol is called SNMPv3 and described in RFC 1906
         [RFC1906], RFC 2572 [RFC2572] and RFC 2574 [RFC2574].

      o  Protocol operations for accessing management information.  The
         first set of protocol operations and associated PDU formats is
         described in STD 15, RFC 1157 [RFC1157].  A second set of
         protocol operations and associated PDU formats is described in
         RFC 1905 [RFC1905].

      o  A set of fundamental applications described in RFC 2573
         [RFC2573] and the view-based access control mechanism described
         in RFC 2575 [RFC2575].

   A more detailed introduction to the current SNMP Management Framework
   can be found in RFC 2570 [RFC2570].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the mechanisms defined in the SMI.

   This memo specifies a MIB module that is compliant to the SMIv2.  A
   MIB conforming to the SMIv1 can be produced through the appropriate
   translations.  The resulting translated MIB must be semantically
   equivalent, except where objects or events are omitted because no
   translation is possible (use of Counter64).  Some machine readable





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RFC 2959                        RTP MIB                     October 2000


   information in SMIv2 will be converted into textual descriptions in
   SMIv1 during the translation process.  However, this loss of machine
   readable information is not considered to change the semantics of the
   MIB.

2. Overview

   An "RTP System" may be a host end-system that runs an application
   program that sends or receives RTP data packets, or it may be an
   intermediate-system that forwards RTP packets.  RTP Control Protocol
   (RTCP) packets are sent by senders and receivers to convey
   information about RTP packet transmission and reception [RFC1889].
   RTP monitors may collect RTCP information on senders and receivers to
   and from an RTP host or intermediate-system.

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

2.1 Components

   The RTP MIB is structured around "Session," "Receiver" and "Sender"
   conceptual abstractions.

   2.1.1  An "RTP Session" is the "...association of participants
   communicating with RTP.  For each participant, the session is defined
   by a particular pair of destination transport addresses (one network
   address plus a port pair for RTP and RTCP).  The destination
   transport addresses may be common for all participants, as in the
   case of IP multicast, or may be different for each, as in the case of
   individual unicast addresses plus a common port pair," as defined in
   section 3 of [RFC1889].

   2.1.2 A "Sender" is identified within an RTP session by a 32-bit
   numeric "Synchronization Source," or "SSRC", value and is "...the
   source of a stream of RTP packets" as defined in section 3 of
   [RFC1889].  The sender is also a source of RTCP Sender Report packets
   as specified in section 6 of [RFC1889].

   2.1.3 A "Receiver" of a "stream of RTP packets" can be a unicast or
   multicast Receiver as described in 2.1.1, above.  An RTP Receiver has
   an SSRC value that is unique to the session.  An RTP Receiver is a
   source of RTCP Receiver Reports as specified in section 6 of
   [RFC1889].







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RFC 2959                        RTP MIB                     October 2000


2.2 Applicability of the MIB to RTP System Implementations

   The RTP MIB may be used in two types of RTP implementations, RTP Host
   Systems (end systems) and RTP Monitors, see section 3 of [RFC1889].
   Use of the RTP MIB for RTP Translators and Mixers, as defined in
   section 7 of [RFC1889], is for further study.

   2.2.1 RTP host Systems are end-systems that may use the RTP MIB to
   collect RTP session and stream data that the host is sending or
   receiving; these data may be used by a network manager to detect and
   diagnose faults that occur over the lifetime of an RTP session as in
   a "help-desk" scenario.

   2.2.2 RTP Monitors of multicast RTP sessions may be third-party or
   may be located in the RTP host.  RTP Monitors may use the RTP MIB to
   collect RTP session and stream statistical data; these data may be
   used by a network manager for capacity planning and other network-
   management purposes.  An RTP Monitor may use the RTP MIB to collect
   data to permit a network manager to detect and diagnose faults in RTP
   sessions or to permit a network manger to configure its operation.

   2.2.3 Many host systems will want to keep track of streams beyond
   what they are sending and receiving.  In a host monitor system, a
   host agent would use RTP data from the host to maintain data about
   streams it is sending and receiving, and RTCP data to collect data
   about other hosts in the session.  For example, an agent for an RTP
   host that is sending a stream would use data from its RTP system to
   maintain the rtpSenderTable, but it may want to maintain a
   rtpRcvrTable for endpoints that are receiving its stream.  To do this
   the RTP agent will collect RTCP data from the receivers of its stream
   to build the rtpRcvrTable.  A host monitor system MUST set the
   rtpSessionMonitor object to 'true(1)', but it does not have to accept
   management operations that create and destroy rows in its
   rtpSessionTable.

2.3  The Structure of the RTP MIB

   There are six tables in the RTP MIB.  The rtpSessionTable contains
   objects that describe active sessions at the host, or monitor.  The
   rtpSenderTable contains information about senders to the RTP session.
   The rtpRcvrTable contains information about receivers of RTP session
   data.  The rtpSessionInverseTable, rtpSenderInverseTable, and
   rtpRcvrInverseTable contain information to efficiently find indexes
   into the rtpSessionTable, rtpSenderTable, and rtpRcvrTable,
   respectively.






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RFC 2959                        RTP MIB                     October 2000


   The reverse lookup tables (rtpSessionInverseTable,
   rtpSenderInverseTable, and rtpRcvrInverseTable) are optional tables
   to help management applications efficiently access conceptual rows in
   other tables.  Implementors of this MIB SHOULD implement these tables
   for multicast RTP sessions when table indexes (rtpSessionIndex of
   rtpSessionTable, rtpSenderSSRC of rtpSenderTable, and the SSRC pair
   in the rtpRcvrTable) are not available from other MIBs.  Otherwise,
   the management application may be forced to perform expensive tree
   walks through large numbers of sessions, senders, or receivers.

   For any particular RTP session, the rtpSessionMonitor object
   indicates whether remote senders or receivers to the RTP session are
   to be monitored.  If rtpSessionMonitor is true(1) then senders and
   receivers to the session MUST be monitored with entries in the
   rtpSenderTable and rtpRcvrTable.  RTP sessions are monitored by the
   RTP agent that updates rtpSenderTable and rtpRcvrTable objects with
   information from RTCP reports from remote senders or remote receivers
   respectively.

   rtpSessionNewIndex is a global object that permits a network-
   management application to obtain a unique index for conceptual row
   creation in the rtpSessionTable.  In this way the SNMP Set operation
   MAY be used to configure a monitor.

3. Definitions

RTP-MIB DEFINITIONS ::= BEGIN
IMPORTS
       Counter32, Counter64, Gauge32, mib-2, Integer32,
       MODULE-IDENTITY,
       OBJECT-TYPE, Unsigned32                     FROM SNMPv2-SMI
       RowStatus, TAddress,
       TDomain, TestAndIncr,
       TimeStamp, TruthValue                       FROM SNMPv2-TC
       OBJECT-GROUP, MODULE-COMPLIANCE             FROM SNMPv2-CONF
       Utf8String                                  FROM SYSAPPL-MIB
       InterfaceIndex                              FROM IF-MIB;

rtpMIB MODULE-IDENTITY
    LAST-UPDATED "200010020000Z"  -- 2 October 2000
    ORGANIZATION
                 "IETF AVT Working Group
    Email:   [e-mail]"
    CONTACT-INFO
            "Mark Baugher
    Postal: Intel Corporation
            2111 NE 25th Avenue
            Hillsboro, OR   97124



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RFC 2959                        RTP MIB                     October 2000


            United States
    Tel:    [phone]
    Email:  [e-mail]

            Bill Strahm
    Postal: Intel Corporation
            2111 NE 25th Avenue
            Hillsboro, OR   97124
            United States
    Tel:    [phone]
    Email:  [e-mail]

            Irina Suconick
    Postal: Ennovate Networks
            60 Codman Hill Rd.,
            Boxboro, Ma 01719
    Tel:    [phone]
    Email:  [e-mail]"

        DESCRIPTION
        "The managed objects of RTP systems.  The MIB is
        structured around three types of information.
        1. General information about RTP sessions such
           as the session address.
        2. Information about RTP streams being sent to
           an RTP session by a particular sender.
        3. Information about RTP streams received on an
           RTP session by a particular receiver from a
           particular sender.
         There are two types of RTP Systems, RTP hosts and
         RTP monitors.  As described below, certain objects
         are unique to a particular type of RTP System.   An
         RTP host may also function as an RTP monitor.
         Refer to RFC 1889, 'RTP: A Transport Protocol for
         Real-Time Applications,' section 3.0, for definitions."
   REVISION     "200010020000Z"  -- 2 October 2000
   DESCRIPTION  "Initial version of this MIB.
                 Published as RFC 2959."

::= { mib-2 87 }

--
-- OBJECTS
--
rtpMIBObjects OBJECT IDENTIFIER ::= { rtpMIB 1 }
rtpConformance OBJECT IDENTIFIER ::= { rtpMIB 2 }

--



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RFC 2959                        RTP MIB                     October 2000


-- SESSION NEW INDEX
--
rtpSessionNewIndex OBJECT-TYPE
    SYNTAX          TestAndIncr
    MAX-ACCESS      read-write
    STATUS          current