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
1. The SNMP Management Framework
The SNMP Management Framework presently consists of five major
components:
o An overall architecture, described in RFC2571 [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, RFC1155 [RFC1155], STD 16, RFC1212 [RFC1212] and RFC
1215 [RFC1215]. The second version, called SMIv2, is described
in STD 58, RFC2578 [RFC2578], RFC2579 [RFC2579] and RFC2580
[RFC2580].
o Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
described in STD 15, RFC1157 [RFC1157]. A second version of
the SNMP message protocol, which is not an Internet standards
track protocol, is called SNMPv2c and described in RFC1901
[RFC1901] and RFC1906 [RFC1906]. The third version of the
message protocol is called SNMPv3 and described in RFC1906
[RFC1906], RFC2572 [RFC2572] and RFC2574 [RFC2574].
o Protocol operations for Accessing management information. The
first set of protocol operations and associated PDU formats is
described in STD 15, RFC1157 [RFC1157]. A second set of
protocol operations and associated PDU formats is described in
RFC1905 [RFC1905].
o A set of fundamental applications described in RFC2573
[RFC2573] and the view-based access control mechanism described
in RFC2575 [RFC2575].
A more detailed introduction to the current SNMP Management Framework
can be found in RFC2570 [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
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 RFC2119.
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].
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.
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: rem-conf@es.net"
CONTACT-INFO
"Mark Baugher
Postal: Intel Corporation
2111 NE 25th Avenue
Hillsboro, OR 97124
United States
Tel: +1 503 466 8406
Email: mbaugher@passedge.com
Bill Strahm
Postal: Intel Corporation
2111 NE 25th Avenue
Hillsboro, OR 97124
United States
Tel: +1 503 264 4632
Email: bill.strahm@intel.com
Irina Suconick
Postal: Ennovate Networks
60 Codman Hill Rd.,
Boxboro, Ma 01719
Tel: +1 781-505-2155
Email: irina@ennovatenetworks.com"
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 RFC1889, '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 RFC2959."
::= { mib-2 87 }
--
-- OBJECTS
--
rtpMIBObjects OBJECT IDENTIFIER ::= { rtpMIB 1 }
rtpConformance OBJECT IDENTIFIER ::= { rtpMIB 2 }
--
-- SESSION NEW INDEX
--
rtpSessionNewIndex OBJECT-TYPE
SYNTAX TestAndIncr
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object is used to assign values to rtpSessionIndex
as described in 'Textual Conventions for SMIv2'. For an RTP
system that supports the creation of rows, the network manager
would read the object, and then write the value back in
the Set that creates a new instance of rtpSessionEntry. If
the Set fails with the code 'inconsistentValue,' then the
process must be repeated; If the Set succeeds, then the object
is incremented, and the new instance is created according to
the manager's directions. However, if the RTP agent is not
acting as a monitor, only the RTP agent may create conceptual
rows in the RTP session table."
::= { rtpMIBObjects 1 }
--
-- SESSION INVERSE TABLE
--
rtpSessionInverseTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpSessionInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Maps rtpSessionDomain, rtpSessionRemAddr, and rtpSessionLocAddr
TAddress pairs to one or more rtpSessionIndex values, each
describing a row in the rtpSessionTable. This makes it possible
to retrieve the row(s) in the rtpSessionTable corresponding to a
given session without having to walk the entire (potentially
large) table."
::= { rtpMIBObjects 2 }
rtpSessionInverseEntry OBJECT-TYPE
SYNTAX RtpSessionInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry corresponds to exactly one entry in the
rtpSessionTable - the entry containing the tuple,
rtpSessionDomain, rtpSessionRemAddr, rtpSessionLocAddr
and rtpSessionIndex."
INDEX { rtpSessionDomain, rtpSessionRemAddr, rtpSessionLocAddr,
rtpSessionIndex }
::= { rtpSessionInverseTable 1 }
RtpSessionInverseEntry ::= SEQUENCE {
rtpSessionInverseStartTime TimeStamp
}
rtpSessionInverseStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpSessionInverseEntry 1 }
--
-- SESSION TABLE
--
rtpSessionTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpSessionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"There's one entry in rtpSessionTable for each RTP session
on which packets are being sent, received, and/or
monitored."
::= { rtpMIBObjects 3 }
rtpSessionEntry OBJECT-TYPE
SYNTAX RtpSessionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Data in rtpSessionTable uniquely identify an RTP session. A
host RTP agent MUST create a read-only row for each session to
which packets are being sent or received. Rows MUST be created
by the RTP Agent at the start of a session when one or more
senders or receivers are observed. Rows created by an RTP agent
MUST be deleted when the session is over and there are no
rtpRcvrEntry and no rtpSenderEntry for this session. An RTP
session SHOULD be monitored to create management information on
all RTP streams being sent or received when the
rtpSessionMonitor has the TruthValue of 'true(1)'. An RTP
monitor SHOULD permit row creation with the side effect of
causing the RTP System to join the multicast session for the
purposes of gathering management information (additional
conceptual rows are created in the rtpRcvrTable and
rtpSenderTable). Thus, rtpSessionTable rows SHOULD be created
for RTP session monitoring purposes. Rows created by a
management application SHOULD be deleted via SNMP operations by
management applications. Rows created by management operations
are deleted by management operations by setting
rtpSessionRowStatus to 'destroy(6)'."
INDEX { rtpSessionIndex }
::= { rtpSessionTable 1 }
RtpSessionEntry ::= SEQUENCE {
rtpSessionIndex Integer32,
rtpSessionDomain TDomain,
rtpSessionRemAddr TAddress,
rtpSessionLocAddr TAddress,
rtpSessionIfIndex InterfaceIndex,
rtpSessionSenderJoins Counter32,
rtpSessionReceiverJoins Counter32,
rtpSessionByes Counter32,
rtpSessionStartTime TimeStamp,
rtpSessionMonitor TruthValue,
rtpSessionRowStatus RowStatus
}
rtpSessionIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The index of the conceptual row which is for SNMP purposes
only and has no relation to any protocol value. There is
no requirement that these rows are created or maintained
sequentially."
::= { rtpSessionEntry 1 }
rtpSessionDomain OBJECT-TYPE
SYNTAX TDomain
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The transport-layer protocol used for sending or receiving
the stream of RTP data packets on this session.
Cannot be changed if rtpSessionRowStatus is 'active'."
::= { rtpSessionEntry 2 }
rtpSessionRemAddr OBJECT-TYPE
SYNTAX TAddress
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The address to which RTP packets are sent by the RTP system.
In an IP multicast RTP session, this is the single address used
by all senders and receivers of RTP session data. In a unicast
RTP session this is the unicast address of the remote RTP system.
'The destination address pair 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 network address pairs.' See
RFC1889, 'RTP: A Transport Protocol for Real-Time Applications,'
sec. 3. The transport service is identified by rtpSessionDomain.
For snmpUDPDomain, this is an IP address and even-numbered UDP
Port with the RTCP being sent on the next higher odd-numbered
port, see RFC1889, sec. 5."
::= { rtpSessionEntry 3 }
rtpSessionLocAddr OBJECT-TYPE
SYNTAX TAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The local address used by the RTP system. In an IP multicast
RTP session, rtpSessionRemAddr will be the same IP multicast
address as rtpSessionLocAddr. In a unicast RTP session,
rtpSessionRemAddr and rtpSessionLocAddr will have different
unicast addresses. See RFC1889, 'RTP: A Transport Protocol for
Real-Time Applications,' sec. 3. The transport service is
identified by rtpSessionDomain. For snmpUDPDomain, this is an IP
address and even-numbered UDP Port with the RTCP being sent on
the next higher odd-numbered port, see RFC1889, sec. 5."
::= { rtpSessionEntry 4 }
rtpSessionIfIndex OBJECT-TYPE
SYNTAX InterfaceIndex
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The ifIndex value is set to the corresponding value
from IF-MIB (See RFC2233, 'The Interfaces Group MIB using
SMIv2'). This is the interface that the RTP stream is being sent
to or received from, or in the case of an RTP Monitor the
interface that RTCP packets will be received on. Cannot be
changed if rtpSessionRowStatus is 'active'."
::= { rtpSessionEntry 5 }
rtpSessionSenderJoins OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of senders that have been observed to have
joined the session since this conceptual row was created
(rtpSessionStartTime). A sender 'joins' an RTP
session by sending to it. Senders that leave and then
re-join following an RTCP BYE (see RFC1889, 'RTP: A
Transport Protocol for Real-Time Applications,' sec. 6.6)
or session timeout may be counted twice. Every time a new
RTP sender is detected either using RTP or RTCP, this counter
is incremented."
::= { rtpSessionEntry 6 }
rtpSessionReceiverJoins OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of receivers that have been been observed to
have joined this session since this conceptual row was
created (rtpSessionStartTime). A receiver 'joins' an RTP
session by sending RTCP Receiver Reports to the session.
Receivers that leave and then re-join following an RTCP BYE
(see RFC1889, 'RTP: A Transport Protocol for Real-Time
Applications,' sec. 6.6) or session timeout may be counted
twice."
::= { rtpSessionEntry 7 }
rtpSessionByes OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of RTCP BYE (see RFC1889, 'RTP: A Transport
Protocol for Real-Time Applications,' sec. 6.6) messages
received by this entity."
::= { rtpSessionEntry 8 }
rtpSessionStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpSessionEntry 9 }
rtpSessionMonitor OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Boolean, Set to 'true(1)' if remote senders or receivers in
addition to the local RTP System are to be monitored using RTCP.
RTP Monitors MUST initialize to 'true(1)' and RTP Hosts SHOULD
initialize this 'false(2)'. Note that because 'host monitor'
systems are receiving RTCP from their remote participants they
MUST set this value to 'true(1)'."
::= { rtpSessionEntry 10 }
rtpSessionRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Value of 'active' when RTP or RTCP messages are being
sent or received by an RTP System. A newly-created
conceptual row must have the all read-create objects
initialized before becoming 'active'.
A conceptual row that is in the 'notReady' or 'notInService'
state MAY be removed after 5 minutes."
::= { rtpSessionEntry 11 }
--
-- SENDER INVERSE TABLE
--
rtpSenderInverseTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpSenderInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Maps rtpSenderAddr, rtpSessionIndex, to the rtpSenderSSRC
index of the rtpSenderTable. This table allows management
applications to find entries sorted by rtpSenderAddr rather than
sorted by rtpSessionIndex. Given the rtpSessionDomain and
rtpSenderAddr, a set of rtpSessionIndex and rtpSenderSSRC values
can be returned from a tree walk. When rtpSessionIndex is
specified in the SNMP Get-Next operations, one or more
rtpSenderSSRC values may be returned."
::= { rtpMIBObjects 4 }
rtpSenderInverseEntry OBJECT-TYPE
SYNTAX RtpSenderInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry corresponds to exactly one entry in the
rtpSenderTable - the entry containing the index pair,
rtpSessionIndex, rtpSenderSSRC."
INDEX { rtpSessionDomain, rtpSenderAddr, rtpSessionIndex,
rtpSenderSSRC }
::= { rtpSenderInverseTable 1 }
RtpSenderInverseEntry ::= SEQUENCE {
rtpSenderInverseStartTime TimeStamp
}
rtpSenderInverseStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpSenderInverseEntry 1 }
--
-- SENDERS TABLE
--
rtpSenderTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpSenderEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Table of information about a sender or senders to an RTP
Session. RTP sending hosts MUST have an entry in this table
for each stream being sent. RTP receiving hosts MAY have an
entry in this table for each sending stream being received by
this host. RTP monitors MUST create an entry for each observed
sender to a multicast RTP Session as a side-effect when a
conceptual row in the rtpSessionTable is made 'active' by a
manager."
::= { rtpMIBObjects 5 }
rtpSenderEntry OBJECT-TYPE
SYNTAX RtpSenderEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry contains information from a single RTP Sender
Synchronization Source (SSRC, see RFC1889 'RTP: A Transport
Protocol for Real-Time Applications' sec.6). The session is
identified to the the SNMP entity by rtpSessionIndex.
Rows are removed by the RTP agent when a BYE is received
from the sender or when the sender times out (see RFC
1889, Sec. 6.2.1) or when the rtpSessionEntry is deleted."
INDEX { rtpSessionIndex, rtpSenderSSRC }
::= { rtpSenderTable 1 }
RtpSenderEntry ::= SEQUENCE {
rtpSenderSSRC Unsigned32,
rtpSenderCNAME Utf8String,
rtpSenderAddr TAddress,
rtpSenderPackets Counter64,
rtpSenderOctets Counter64,
rtpSenderTool Utf8String,
rtpSenderSRs Counter32,
rtpSenderSRTime TimeStamp,
rtpSenderPT INTEGER,
rtpSenderStartTime TimeStamp
}
rtpSenderSSRC OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The RTP SSRC, or synchronization source identifier of the
sender. The RTP session address plus an SSRC uniquely
identify a sender to an RTP session (see RFC1889, 'RTP: A
Transport Protocol for Real-Time Applications' sec.3)."
::= { rtpSenderEntry 1 }
rtpSenderCNAME OBJECT-TYPE
SYNTAX Utf8String
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The RTP canonical name of the sender."
::= { rtpSenderEntry 2 }
rtpSenderAddr OBJECT-TYPE
SYNTAX TAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The unicast transport source address of the sender. In the
case of an RTP Monitor this address is the address that the
sender is using to send its RTCP Sender Reports."
::= { rtpSenderEntry 3 }
rtpSenderPackets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Count of RTP packets sent by this sender, or observed by
an RTP monitor, since rtpSenderStartTime."
::= { rtpSenderEntry 4 }
rtpSenderOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Count of non-header RTP octets sent by this sender, or observed
by an RTP monitor, since rtpSenderStartTime."
::= { rtpSenderEntry 5 }
rtpSenderTool OBJECT-TYPE
SYNTAX Utf8String (SIZE(0..127))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Name of the application program source of the stream."
::= { rtpSenderEntry 6 }
rtpSenderSRs OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of the number of RTCP Sender Reports that have
been sent from this sender, or observed if the RTP entity
is a monitor, since rtpSenderStartTime."
::= { rtpSenderEntry 7 }
rtpSenderSRTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"rtpSenderSRTime is the value of SysUpTime at the time that
the last SR was received from this sender, in the case of a
monitor or receiving host. Or sent by this sender, in the
case of a sending host."
::= { rtpSenderEntry 8 }
rtpSenderPT OBJECT-TYPE
SYNTAX INTEGER (0..127)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Payload type from the RTP header of the most recently received
RTP Packet (see RFC1889, 'RTP: A Transport Protocol for
Real-Time Applications' sec. 5)."
::= { rtpSenderEntry 9 }
rtpSenderStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpSenderEntry 10 }
--
-- RECEIVER INVERSE TABLE
--
rtpRcvrInverseTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpRcvrInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Maps rtpRcvrAddr and rtpSessionIndex to the rtpRcvrSRCssRC and
rtpRcvrSSRC indexes of the rtpRcvrTable. This table allows
management applications to find entries sorted by rtpRcvrAddr
rather than by rtpSessionIndex. Given rtpSessionDomain and
rtpRcvrAddr, a set of rtpSessionIndex, rtpRcvrSRCSSRC, and
rtpRcvrSSRC values can be returned from a tree walk. When
rtpSessionIndex is specified in SNMP Get-Next operations, one or
more rtpRcvrSRCSSRC and rtpRcvrSSRC pairs may be returned."
::= { rtpMIBObjects 6 }
rtpRcvrInverseEntry OBJECT-TYPE
SYNTAX RtpRcvrInverseEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry corresponds to exactly one entry in the
rtpRcvrTable - the entry containing the index pair,
rtpSessionIndex, rtpRcvrSSRC."
INDEX { rtpSessionDomain, rtpRcvrAddr, rtpSessionIndex,
rtpRcvrSRCSSRC, rtpRcvrSSRC }
::= { rtpRcvrInverseTable 1 }
RtpRcvrInverseEntry ::= SEQUENCE {
rtpRcvrInverseStartTime TimeStamp
}
rtpRcvrInverseStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpRcvrInverseEntry 1 }
--
-- RECEIVERS TABLE
--
rtpRcvrTable OBJECT-TYPE
SYNTAX SEQUENCE OF RtpRcvrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Table of information about a receiver or receivers of RTP
session data. RTP hosts that receive RTP session packets
MUST create an entry in this table for that receiver/sender
pair. RTP hosts that send RTP session packets MAY create
an entry in this table for each receiver to their stream
using RTCP feedback from the RTP group. RTP monitors
create an entry for each observed RTP session receiver as
a side effect when a conceptual row in the rtpSessionTable
is made 'active' by a manager."
::= { rtpMIBObjects 7 }
rtpRcvrEntry OBJECT-TYPE
SYNTAX RtpRcvrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each entry contains information from a single RTP
Synchronization Source that is receiving packets from the
sender identified by rtpRcvrSRCSSRC (SSRC, see RFC1889,
'RTP: A Transport Protocol for Real-Time Applications'
sec.6). The session is identified to the the RTP Agent entity
by rtpSessionIndex. Rows are removed by the RTP agent when
a BYE is received from the sender or when the sender times
out (see RFC1889, Sec. 6.2.1) or when the rtpSessionEntry is
deleted."
INDEX { rtpSessionIndex, rtpRcvrSRCSSRC, rtpRcvrSSRC }
::= { rtpRcvrTable 1 }
RtpRcvrEntry ::= SEQUENCE {
rtpRcvrSRCSSRC Unsigned32,
rtpRcvrSSRC Unsigned32,
rtpRcvrCNAME Utf8String,
rtpRcvrAddr TAddress,
rtpRcvrRTT Gauge32,
rtpRcvrLostPackets Counter64,
rtpRcvrJitter Gauge32,
rtpRcvrTool Utf8String,
rtpRcvrRRs Counter32,
rtpRcvrRRTime TimeStamp,
rtpRcvrPT INTEGER,
rtpRcvrPackets Counter64,
rtpRcvrOctets Counter64,
rtpRcvrStartTime TimeStamp
}
rtpRcvrSRCSSRC OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The RTP SSRC, or synchronization source identifier of the
sender. The RTP session address plus an SSRC uniquely
identify a sender or receiver of an RTP stream (see RFC
1889, 'RTP: A Transport Protocol for Real-Time
Applications' sec.3)."
::= { rtpRcvrEntry 1 }
rtpRcvrSSRC OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The RTP SSRC, or synchronization source identifier of the
receiver. The RTP session address plus an SSRC uniquely
identify a receiver of an RTP stream (see RFC1889, 'RTP:
A Transport Protocol for Real-Time Applications' sec.3)."
::= { rtpRcvrEntry 2 }
rtpRcvrCNAME OBJECT-TYPE
SYNTAX Utf8String
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The RTP canonical name of the receiver."
::= { rtpRcvrEntry 3 }
rtpRcvrAddr OBJECT-TYPE
SYNTAX TAddress
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The unicast transport address on which the receiver is
receiving RTP packets and/or RTCP Receiver Reports."
::= { rtpRcvrEntry 4 }
rtpRcvrRTT OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The round trip time measurement taken by the source of the
RTP stream based on the algorithm described on sec. 6 of
RFC1889, 'RTP: A Transport Protocol for Real-Time
Applications.' This algorithm can produce meaningful
results when the RTP agent has the same clock as the stream
sender (when the RTP monitor is also the sending host for the
particular receiver). Otherwise, the entity should return
'noSuchInstance' in response to queries against rtpRcvrRTT."
::= { rtpRcvrEntry 5 }
rtpRcvrLostPackets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of RTP packets lost as observed by this receiver
since rtpRcvrStartTime."
::= { rtpRcvrEntry 6 }
rtpRcvrJitter OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An estimate of delay variation as observed by this
receiver. (see RFC1889, 'RTP: A Transport Protocol
for Real-Time Applications' sec.6.3.1 and A.8)."
::= { rtpRcvrEntry 7 }
rtpRcvrTool OBJECT-TYPE
SYNTAX Utf8String (SIZE(0..127))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Name of the application program source of the stream."
::= { rtpRcvrEntry 8 }
rtpRcvrRRs OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of the number of RTCP Receiver Reports that have
been sent from this receiver, or observed if the RTP entity
is a monitor, since rtpRcvrStartTime."
::= { rtpRcvrEntry 9 }
rtpRcvrRRTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"rtpRcvrRRTime is the value of SysUpTime at the time that the
last RTCP Receiver Report was received from this receiver, in
the case of a monitor or RR receiver (the RTP Sender). It is
the value of SysUpTime at the time that the last RR was sent by
this receiver in the case of an RTP receiver sending the RR."
::= { rtpRcvrEntry 10 }
rtpRcvrPT OBJECT-TYPE
SYNTAX INTEGER (0..127)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Static or dynamic payload type from the RTP header (see
RFC1889, 'RTP: A Transport Protocol for Real-Time
Applications' sec. 5)."
::= { rtpRcvrEntry 11 }
rtpRcvrPackets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Count of RTP packets received by this RTP host receiver
since rtpRcvrStartTime."
::= { rtpRcvrEntry 12 }
rtpRcvrOctets OBJECT-TYPE
SYNTAX Counter64
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Count of non-header RTP octets received by this receiving RTP
host since rtpRcvrStartTime."
::= { rtpRcvrEntry 13 }
rtpRcvrStartTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of SysUpTime at the time that this row was
created."
::= { rtpRcvrEntry 14 }
--
-- MODULE GROUPS
--
--
-- There are two types of RTP Systems, RTP hosts and RTP Monitors.
-- Thus there are three kinds of objects: 1) Objects common to both
-- kinds of systems, 2) Objects unique to RTP Hosts and 3) Objects
-- unique to RTP Monitors. There is a fourth group, 4) Objects that
-- SHOULD be implemented by Multicast hosts and RTP Monitors
rtpGroups OBJECT IDENTIFIER ::= { rtpConformance 1 }
rtpSystemGroup OBJECT-GROUP
OBJECTS {
rtpSessionDomain,
rtpSessionRemAddr,
rtpSessionIfIndex,
rtpSessionSenderJoins,
rtpSessionReceiverJoins,
rtpSessionStartTime,
rtpSessionByes,
rtpSessionMonitor,
rtpSenderCNAME,
rtpSenderAddr,
rtpSenderPackets,
rtpSenderOctets,
rtpSenderTool,
rtpSenderSRs,
rtpSenderSRTime,
rtpSenderStartTime,
rtpRcvrCNAME,
rtpRcvrAddr,
rtpRcvrLostPackets,
rtpRcvrJitter,
rtpRcvrTool,
rtpRcvrRRs,
rtpRcvrRRTime,
rtpRcvrStartTime
}
STATUS current
DESCRIPTION
"Objects available to all RTP Systems."
::= { rtpGroups 1 }
rtpHostGroup OBJECT-GROUP
OBJECTS {
rtpSessionLocAddr,
rtpSenderPT,
rtpRcvrPT,
rtpRcvrRTT,
rtpRcvrOctets,
rtpRcvrPackets
}
STATUS current
DESCRIPTION
"Objects that are available to RTP Host systems, but may not
be available to RTP Monitor systems."
::= { rtpGroups 2 }
rtpMonitorGroup OBJECT-GROUP
OBJECTS {
rtpSessionNewIndex,
rtpSessionRowStatus
}
STATUS current
DESCRIPTION
"Objects used to create rows in the RTP Session Table. These
objects are not needed if the system does not create rows."
::= { rtpGroups 3 }
rtpInverseGroup OBJECT-GROUP
OBJECTS {
rtpSessionInverseStartTime,
rtpSenderInverseStartTime,
rtpRcvrInverseStartTime
}
STATUS current
DESCRIPTION
"Objects used in the Inverse Lookup Tables."
::= { rtpGroups 4 }
--
-- Compliance
--
rtpCompliances OBJECT IDENTIFIER ::= { rtpConformance 2 }
rtpHostCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"Host implementations MUST comply."
MODULE RTP-MIB
MANDATORY-GROUPS {
rtpSystemGroup,
rtpHostGroup
}
GROUP rtpMonitorGroup
DESCRIPTION
"Host systems my optionally support row creation and deletion.
This would allow an RTP Host system to act as an RTP Monitor."
GROUP rtpInverseGroup
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpSessionNewIndex
MIN-ACCESS not-accessible
DESCRIPTION
"RTP system implementations support of
row creation and deletion is OPTIONAL so
implementation of this object is OPTIONAL."
OBJECT rtpSessionDomain
MIN-ACCESS read-only
DESCRIPTION
"RTP system implementation support of
row creation and deletion is OPTIONAL. When
it is not supported so write access is
OPTIONAL."
OBJECT rtpSessionRemAddr
MIN-ACCESS read-only
DESCRIPTION
"Row creation and deletion is OPTIONAL so
read-create access to this object is OPTIONAL."
OBJECT rtpSessionIfIndex
MIN-ACCESS read-only
DESCRIPTION
"Row creation and deletion is OPTIONAL so
read-create access to this object is OPTIONAL."
OBJECT rtpSessionRowStatus
MIN-ACCESS not-accessible
DESCRIPTION
"Row creation and deletion is OPTIONAL so
read-create access to this object is OPTIONAL."
OBJECT rtpSessionInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpSenderInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpRcvrInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
::= { rtpCompliances 1 }
rtpMonitorCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"Monitor implementations must comply. RTP Monitors are not
required to support creation or deletion."
MODULE RTP-MIB
MANDATORY-GROUPS {
rtpSystemGroup,
rtpMonitorGroup
}
GROUP rtpHostGroup
DESCRIPTION
"Monitor implementations may not have access to values in the
rtpHostGroup."
GROUP rtpInverseGroup
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpSessionLocAddr
MIN-ACCESS not-accessible
DESCRIPTION
"RTP monitor sourcing of RTP or RTCP data packets
is OPTIONAL and implementation of this object is
OPTIONAL."
OBJECT rtpRcvrPT
MIN-ACCESS not-accessible
DESCRIPTION
"RTP monitor systems may not support
retrieval of the RTP Payload Type from the RTP
header (and may receive RTCP messages only). When
queried for the payload type information"
OBJECT rtpSenderPT
MIN-ACCESS not-accessible
DESCRIPTION
"RTP monitor systems may not support
retrieval of the RTP Payload Type from the RTP
header (and may receive RTCP messages only). When
queried for the payload type information."
OBJECT rtpRcvrOctets
MIN-ACCESS not-accessible
DESCRIPTION
"RTP monitor systems may receive only the RTCP messages
and not the RTP messages that contain the octet count
of the RTP message. Thus implementation of this
object is OPTIONAL"
OBJECT rtpRcvrPackets
MIN-ACCESS not-accessible
DESCRIPTION
"RTP monitor systems may receive only the RTCP messages
and not the RTP messages that contain the octet count
of the RTP message. Thus implementation of this
object is OPTIONAL."
OBJECT rtpSessionIfIndex
MIN-ACCESS read-only
DESCRIPTION
"Row creation and deletion is OPTIONAL so
read-create access to this object is OPTIONAL."
OBJECT rtpSessionInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpSenderInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
OBJECT rtpRcvrInverseStartTime
MIN-ACCESS not-accessible
DESCRIPTION
"Multicast RTP Systems SHOULD implement the optional
tables."
::= { rtpCompliances 2 }
END
4. Security Considerations
In most cases, MIBs are not themselves security risks; if SNMP
security is operating as intended, the use of a MIB to view
information about a system, or to change some parameter at the
system, is a tool, not a threat. However, there are a number of
management objects defined in this MIB that have a MAX-ACCESS clause
of read-write and/or read-create. Such objects may be considered
sensitive or vulnerable in some network environments. The support
for SET operations in a non-secure environment without proper
protection can have a negative effect on network operations.
None of the read-only objects in this MIB reports a password, though
some SDES [RFC1889] items such as the CNAME [RFC1889], the canonical
name, may be deemed sensitive depending on the security policies of a
particular enterprise. If access to these objects is not limited by
an appropriate access control policy, these objects can provide an
attacker with information about a system's configuration and the
services that that system is providing. Some enterprises view their
network and system configurations, as well as information about usage
and performance, as corporate assets; such enterprises may wish to
restrict SNMP access to most of the objects in the MIB. This MIB
supports read-write operations against rtpSessionNewIndex which has
the side effect of creating an entry in the rtpSessionTable when it
is written to. Five objects in rtpSessionEntry have read-create
access: rtpSessionDomain, rtpSessionRemAddr, rtpSessionIfIndex,
rtpSessionRowStatus, and rtpSessionIfAddr identify an RTP session to
be monitored on a particular interface. The values of these objects
are not to be changed once created, and initialization of these
objects affects only the monitoring of an RTP session and not the
operation of an RTP session on any host end-system. Since write
operations to rtpSessionNewIndex and the five objects in
rtpSessionEntry affect the operation of the monitor, write access to
these objects should be subject to the appropriate access control
policy.
Confidentiality of RTP and RTCP data packets is defined in section 9
of the RTP specification [RFC1889]. Encryption may be performed on
RTP packets, RTCP packets, or both. Encryption of RTCP packets may
pose a problem for third-party monitors though "For RTCP, it is
allowed to split a compound RTCP packet into two lower-layer packets,
one to be encrypted and one to be sent in the clear. For example,
SDES information might be encrypted while reception reports were sent
in the clear to accommodate third-party monitors [RFC1889]."
SNMPv1 by itself is not a secure environment. Even if the network
itself is secure (for example by using IPSec), 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. It is
recommended that the implementers consider the security features as
provided by the SNMPv3 framework. Specifically, the use of the
User-based Security Model RFC2574 [RFC2574] and the View-based
Access Control Model RFC2575 [RFC2575] is recommended. It is then a
customer/user responsibility to ensure that the SNMP entity giving
access to an instance of this MIB, 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.
5. Acknowledgements
The authors wish to thank Bert Wijnen and the participants from the
ITU SG-16 management effort for their helpful comments. Alan Batie
and Bill Lewis from Intel also contributed greatly to the RTP MIB
through their review of various drafts of the MIB and their work on
the implementation of an SNMP RTP Monitor. Stan Naudus from 3Com and
John Du from Intel contributed to the original RTP MIB design and
co-authored the original RTP MIB draft documents; much of their work
remains in the current RTP MIB. Bill Fenner provided solid feedback
that improved the quality of the final document.
6. Intellectual Property
The IETF takes no position regarding the validity or scope of any
intellectual property 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; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication 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 implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
7. References
[RFC1889] Shulzrinne, H., Casner, S., Frederick, R. and V.
Jacobson, "RTP: A Transport Protocol for real-time
applications," RFC1889, January 1996.
[RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An
Architecture for Describing SNMP Management Frameworks",
RFC2571, April 1999.
[RFC1155] Rose, M. and K. McCloghrie, "Structure and Identification
of Management Information for TCP/IP-based Internets",
STD 16, RFC1155, May 1990.
[RFC1212] Rose, M. and K. McCloghrie, "Concise MIB Definitions",
STD 16, RFC1212, March 1991.
[RFC1215] Rose, M., "A Convention for Defining Traps for use with
the SNMP", RFC1215, March 1991.
[RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Structure of Management
Information Version 2 (SMIv2)", STD 58, RFC2578, April
1999.
[RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Textual Conventions for
SMIv2", STD 58, RFC2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M. and S. Waldbusser, "Conformance Statements for
SMIv2", STD 58, RFC2580, April 1999.
[RFC1157] Case, J., Fedor, M., Schoffstall, M. and J. Davin,
"Simple Network Management Protocol", STD 15, RFC1157,
May 1990.
[RFC1901] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC1901
