B. Strahm
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 © 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:
-
- 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].
- 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].
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 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].
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 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 }
--
-- 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 RFC 1889, '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 RFC 1889, 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 RFC 1889, '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 RFC 1889, 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 RFC 2233, '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 RFC 1889, '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 RFC 1889, '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 RFC 1889, '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 RFC 1889 '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 RFC 1889, '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 RFC 1889, '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 RFC 1889, '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 RFC 1889, 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 RFC 1889, '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 RFC 1889, '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 RFC 1889, '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 RFC 1889, '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 RFC 2574 [RFC2574] and the View-based Access Control Model RFC 2575 [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," RFC 1889, January 1996. [RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, April 1999. [RFC1155] Rose, M. and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", STD 16, RFC 1155, May 1990. [RFC1212] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16, RFC 1212, March 1991. [RFC1215] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, 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, RFC 2578, April 1999. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999. [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999. [RFC1157] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, May 1990. [RFC1901] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996. [RFC1906] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1906, January 1996. [RFC2572] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, April 1999. [RFC2574] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, April 1999. [RFC1905] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996. [RFC2573] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC 2573, April 1999. [RFC2575] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", RFC 2575, April 1999. [RFC2570] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction to Version 3 of the Internet-standard Network Management Framework", RFC 2570, April 1999.
8. Authors' Addresses
-
Mark Baugher Intel Corporation 2111 N.E.25th Avenue Hillsboro, Oregon 97124 U.S.A.
EMail:
mbaugher@passedge.com Bill Strahm Intel Corporation 2111 N.E.25th Avenue Hillsboro, Oregon 97124 U.S.A. EMail: Bill.Strahm@intel.com
Irina Suconick
Ennovate Networks
60 Codman Hill Rd.,
Boxboro, Ma 01719
U.S.A.EMail:
irina@ennovatenetworks.com
9. Full Copyright Statement
-
Copyright © The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.
The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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.
Acknowledgement
-
Funding for the RFC Editor function is currently provided by the Internet Society.