Network Working Group J. Schoenwaelder, Editor
Internet-Draft TU Braunschweig
Expires September 1999 23 March 1999
SNMP over TCP Transport Mapping
<draft-irtf-nmrg-snmp-tcp-00.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026. Internet-Drafts are
working documents of the Internet Engineering Task Force (IETF), its
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Distribution of this document is unlimited. Please send comments to
the Network Management Research Group, <nmrg@ibr.cs.tu-bs.de>.
Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
This memo defines a transport mapping for using the Simple Network
Management Protocol (SNMP) over TCP. The transport mapping defined in
this memo can be used with any version of SNMP.
J. Schoenwaelder [Page 1]
Internet-Draft SNMP over TCP Transport Mapping January 1999
Table of Contents
1 Introduction ................................................. 3
2 Definitions .................................................. 3
3 SNMP over TCP ................................................ 4
3.1 Serialization .............................................. 4
3.2 Well-known Values .......................................... 4
3.3 Connection Management ...................................... 5
4 Acknowledgments .............................................. 5
5 Editor's Address ............................................. 5
6 Full Copyright Statement ..................................... 6
J. Schoenwaelder [Page 2]
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1. Introduction
This memo defines a transport mapping for using the Simple Network
Management Protocol (SNMP) over TCP. The transport mapping defined in
this memo can be used with any version of SNMP. This document extends
the transport mappings defined in RFC 1906.
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. Definitions
IRTF-NMRG-SNMP-TM DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-IDENTITY, experimental
FROM SNMPv2-SMI
TEXTUAL-CONVENTION
FROM SNMPv2-TC;
nmrgSnmpDomains MODULE-IDENTITY
LAST-UPDATED "9903231800Z"
ORGANIZATION "IRTF Network Management Research Group"
CONTACT-INFO
"Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Tel: +49 531 391-3283
E-mail: schoenw@ibr.cs.tu-bs.de"
DESCRIPTION
"This MIB module defines the SNMP over TCP transport mapping."
::= { experimental nmrg(xxxx) 1 }
-- SNMP over TCP over IPv4
snmpTCPDomain OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The SNMP over TCP/IPv4 transport domain. The corresponding
transport address is of type SnmpTCPAddress."
::= { nmrgSnmpDomains 6 } -- matches first unused value
-- below snmpDomains
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SnmpTCPAddress ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1d.1d.1d.1d/2d"
STATUS current
DESCRIPTION
"Represents a TCP/IPv4 address:
octets contents encoding
1-4 IP-address network-byte order
5-6 TCP-port network-byte order
"
SYNTAX OCTET STRING (SIZE (6))
END
3. SNMP over TCP
This is an optional transport mapping. However, implementors are
encouraged to support SNMP over TCP whenever possible because this
enables applications to use more efficient MIB data transfers.
3.1. Serialization
Each instance of a message is serialized into a single BER encoded
message, using the algorithm specified in Section 8 of RFC 1906. The
BER encoded message is then send over a TCP connection.
Note, it is possible to exchange multiple SNMP request/response pairs
over a single TCP connection. The length field in the BER encoded
SNMP message is used to separate multiple requests send over a single
TCP connection.
3.2. Well-known Values
It is suggested that administrators configure their SNMP entities
acting in an agent role to listen on TCP port 161 for incoming
connections. Further, it is suggested that notification sinks be
configured to listen on TCP port 162.
When an SNMP entity uses this transport mapping, it must be capable
of accepting messages that are at least 484 octets in size.
Implementation of larger values is encouraged whenever possible.
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3.3. Connection Management
The use of TCP connections introduces costs. Connection establishment
and shutdown causes additional traffic on the wire. Further,
maintaining open connections binds resources in the network layer of
the underlying operating system.
TCP connections should therefore only be used when the size of the
data transferred would otherwise cause large latencies due to small
UDP packet sizes and an increased number of interactions.
Both, an SNMP entity in the agent role and an SNMP entity in the
manager role, are allowed to close the connections at any point in
time. This ensures that SNMP entities can control their resource
usage and shutdown TCP connections that are not used. Note, SNMP
engines are not expected to process any outstanding requests if the
underlying TCP connection has been closed. A no response error
condition SHOULD be signalled for outstanding requests for command
generator applications if the TCP connection is closed.
4. Acknowledgments
The definitions in this memo are inspired by definitions found in RFC
1906. This document is the result of the Network Management Research
Group (NMRG). Special thanks go to the following participants for
their comments and contributions:
Luca Deri, Jean-Philippe Martin-Flatin, Aiko Pras, Ron Sprenkels,
Bert Wijnen
5. Editor's Address
Juergen Schoenwaelder Email: schoenw@ibr.cs.tu-bs.de
TU Braunschweig Tel: +49 531 391-3283
Bueltenweg 74/75
38106 Braunschweig
Germany
J. Schoenwaelder [Page 5]
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6. Full Copyright Statement
Copyright (C) The Internet Society (1998). 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.
J. Schoenwaelder [Page 6]
