Pseudowire MIB TCs: Definitions of Textual Conventions for Pseudowire (PW) Management
A shared set of MIB data types for managing pseudowires, so each pseudowire MIB does not reinvent them.
Nadeau, T., Ed., Zelig, D., Ed., and O. Nicklass, Ed., "Definitions of Textual Conventions for Pseudowire (PW) Management", RFC 5542, DOI 10.17487/RFC5542, May 2009, <https://www.rfc-editor.org/info/rfc5542>.
@misc{rfc5542,
series = {Request for Comments},
number = 5542,
howpublished = {RFC 5542},
publisher = {RFC Editor},
doi = {10.17487/RFC5542},
url = {https://www.rfc-editor.org/info/rfc5542},
author = {T. Nadeau and D. Zelig and O. Nicklass},
title = {{Definitions of Textual Conventions for Pseudowire (PW) Management}},
pagetotal = 11,
year = 2009,
month = may,
} RFC text
Contents
Network Working Group T. Nadeau, Ed.
Request for Comments: 5542 BT
Category: Standards Track D. Zelig, Ed.
Oversi
O. Nicklass, Ed.
RADVISION
May 2009
Definitions of Textual Conventions for Pseudowire (PW) Management
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) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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than English.
Abstract
This memo defines a Management Information Base (MIB) module that
contains textual conventions (TCs) to represent commonly used
pseudowire (PW) management information. The intent is that these TCs
will be imported and used in PW-related MIB modules that would
otherwise define their own representations.
Table of Contents
1. Introduction ....................................................2
2. The Internet-Standard Management Framework ......................2
3. Conventions Used in This Document ...............................2
4. Object Definitions ..............................................3
5. Security Considerations .........................................9
6. IANA Considerations .............................................9
7. References .....................................................10
7.1. Normative References ......................................10
7.2. Informative References ....................................10
1. Introduction
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
In particular, it defines textual conventions used for pseudowire
(PW) technology and for Pseudowire Edge-to-Edge Emulation (PWE3) MIB
modules.
2. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through Simple Network Management Protocol (SNMP). Objects
in the MIB are defined using the mechanisms defined in the Structure
of Management Information (SMI). This memo specifies a MIB module
that is compliant to the SMIv2, which is described in STD 58, RFC
2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
[RFC2580].
3. Conventions Used in This Document
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].
4. Object Definitions
PW-TC-STD-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, Unsigned32, mib-2
FROM SNMPv2-SMI -- [RFC2578]
TEXTUAL-CONVENTION
FROM SNMPv2-TC; -- [RFC2579]
pwTcStdMIB MODULE-IDENTITY
LAST-UPDATED "200904210000Z" -- 21 April 2009 00:00:00 GMT
ORGANIZATION "Pseudowire Edge-to-Edge Emulation (PWE3) Working
Group"
CONTACT-INFO
" Thomas D. Nadeau
Email: tom.nadeau@bt.com
David Zelig
Email: davidz@oversi.com
Orly Nicklass
Email: orlyn@radvision.com
The PWE3 Working Group (email distribution pwe3@ietf.org,
http://www.ietf.org/html.charters/pwe3-charter.html)
"
DESCRIPTION
"This MIB module defines TEXTUAL-CONVENTIONS
for concepts used in pseudowire edge-to-edge
networks.
Copyright (c) 2009 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, are permitted provided that the following
conditions are met:
- Redistributions of source code must retain the above
copyright notice, this list of conditions and the following
disclaimer.
- Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials
provided with the distribution.
- Neither the name of Internet Society, IETF or IETF Trust, nor
the names of specific contributors, may be used to endorse or
promote products derived from this software without specific
prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This version of this MIB module is part of RFC 5542;
see the RFC itself for full legal notices."
-- Revision history.
REVISION "200904210000Z" -- 21 April 2009 00:00:00 GMT
DESCRIPTION
"Original Version"
::= { mib-2 188 }
PwGroupID ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An administrative identification for grouping a
set of service-specific pseudowire services."
SYNTAX Unsigned32
PwIDType ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"Pseudowire Identifier. Used to identify the PW
(together with some other fields) in the signaling
session."
SYNTAX Unsigned32
PwIndexType ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"Pseudowire Index. A unique value, greater than zero,
for each locally defined PW. Used for indexing
several MIB tables associated with the particular PW.
It is recommended that values are assigned contiguously
starting from 1. The value for each PW MUST remain
constant at least from one re-initialization
to the next re-initialization."
SYNTAX Unsigned32 (1..4294967295)
PwIndexOrZeroType ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"This TEXTUAL-CONVENTION is an extension of the
PwIndexType convention. The latter defines a greater-
than-zero value used to identify a pseudowire
in the managed system. This extension permits the
additional value of zero. The zero value is object-specific
and MUST therefore be defined as part of the description of
any object that uses this syntax. Examples of the usage of
zero might include situations where pseudowire was unknown,
or where none or all pseudowires need to be referenced."
SYNTAX Unsigned32 (0..4294967295)
PwOperStatusTC ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the operational status of the PW.
- up(1): Ready to pass packets.
- down(2): PW signaling is not yet finished, or
indications available at the service
level indicate that the PW is not
passing packets.
- testing(3): AdminStatus at the PW level is set to
test.
- dormant(4): The PW is not in a condition to pass
packets but is in a 'pending' state,
waiting for some external event.
- notPresent(5): Some component is missing to accomplish
the setup of the PW. It can be
configuration error, incomplete
configuration, or a missing H/W component.
- lowerLayerDown(6): One or more of the lower-layer interfaces
responsible for running the underlying PSN
is not in OperStatus 'up' state."
SYNTAX INTEGER {
up(1),
down(2),
testing(3),
dormant(4),
notPresent(5),
lowerLayerDown(6)
}
PwAttachmentIdentifierType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"An octet string used in the generalized Forward Error
Correction (FEC) element for identifying attachment forwarder
and groups. A NULL identifier is of zero length.
"
SYNTAX OCTET STRING (SIZE (0..255))
PwGenIdType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Represents the Attachment Group Identifier (AGI) Type and
Attachment Individual Identifier (AII) Type in generalized FEC
signaling and configuration.
"
SYNTAX Unsigned32( 0..254 )
PwCwStatusTC ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the status of the control word (CW) negotiation
based on the local configuration and the indications received
from the peer node.
waitingForNextMsg(1) indicates that the node is waiting for
another label mapping from the peer.
sentWrongBitErrorCode(2) indicates that the local node has
notified the peer about a mismatch in the C-bit.
rxWithdrawWithWrongBitErrorCode(3) indicates that a withdraw
message has been received with the wrong C-bit error code.
illegalReceivedBit(4) indicates a C-bit configuration with
the peer that is not compatible with the PW type.
cwPresent(5) indicates that the CW is present for this PW.
If signaling is used, the C-bit is set and agreed upon between
the nodes. For manually configured PW, the local
configuration requires the use of the CW.
cwNotPresent(6) indicates that the CW is not present for this
PW. If signaling is used, the C-bit is reset and agreed upon
between the nodes. For manually configured PW, the local
configuration requires that the CW not be used.
notYetKnown(7) indicates that a label mapping has not yet
been received from the peer.
"
REFERENCE
"Martini, et al., 'Pseudowire Setup and Maintenance Using
the Label Distribution Protocol', [RFC4447]."
SYNTAX INTEGER {
waitingForNextMsg(1),
sentWrongBitErrorCode(2),
rxWithdrawWithWrongBitErrorCode(3),
illegalReceivedBit(4),
cwPresent(5),
cwNotPresent(6),
notYetKnown(7)
}
PwStatus ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the status of the PW and the interfaces affecting
this PW. If none of the bits are set, it indicates no faults
are reported.
"
SYNTAX BITS {
pwNotForwarding(0),
servicePwRxFault(1),
servicePwTxFault(2),
psnPwRxFault(3),
psnPwTxFault(4)
}
PwFragSize ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"If set to a value other than zero, it indicates the desired
fragmentation length in bytes. If set to zero,
fragmentation is not desired for PSN bound packets.
"
SYNTAX Unsigned32
PwFragStatus ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Indicates the status of the fragmentation/reassembly process
based on local configuration and peer capability.
noFrag(0) bit indicates that local configuration is for no
fragmentation.
cfgFragGreaterThanPsnMtu(1) bit indicates that the local node
is set to fragment, but the fragmentation size is greater
than the MTU available at the PSN between the nodes.
Fragmentation is not done in this case.
cfgFragButRemoteIncapable(2) bit indicates that the local
configuration conveys the desire for fragmentation but
the peer is not capable of reassembly.
remoteFragCapable(3) bit indicates that the remote node
is capable to accept fragmented PDUs.
fragEnabled(4) bit indicates that fragmentation will be used
on this PW. Fragmentation can be used if the local node was
configured for fragmentation, the peer has the capability
to accept fragmented packets, and the CW is in use for this
PW."
REFERENCE
"Malis, A. and M. Townsley, 'Pseudowire Emulation Edge-to-
Edge (PWE3) Fragmentation and Reassembly', [RFC4623]."
SYNTAX BITS {
noFrag(0),
cfgFragGreaterThanPsnMtu(1),
cfgFragButRemoteIncapable(2),
remoteFragCapable(3),
fragEnabled(4)
}
PwCfgIndexOrzero ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"Index in any of the relevant configuration tables for
supplement information regarding configuration of the
specific technology. Value zero implies no additional
configuration information is applicable."
SYNTAX Unsigned32 (0..4294967295)
END
5. Security Considerations
This module does not define any management objects. Instead, it
defines a set of textual conventions that may be used by other PWE3
MIB modules to define management objects.
Meaningful security considerations can only be written in the MIB
modules that define management objects. Therefore, this document has
no impact on the security of the Internet.
6. IANA Considerations
The MIB module in this document uses the following IANA-assigned
OBJECT IDENTIFIER value recorded in the SMI Numbers registry:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
pwTcStdMIB { mib-2 188 }
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2578] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Structure of Management Information Version 2 (SMIv2)",
STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Textual Conventions for SMIv2", STD 58, RFC 2579, April
1999.
[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.
[RFC4447] Martini, L., Ed., Rosen, E., El-Aawar, N., Smith, T., and
G. Heron, "Pseudowire Setup and Maintenance Using the
Label Distribution Protocol (LDP)", RFC 4447, April 2006.
[RFC4623] Malis, A. and M. Townsley, "Pseudowire Emulation Edge-to-
Edge (PWE3) Fragmentation and Reassembly", RFC 4623,
August 2006.
7.2. Informative References
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.
Authors' Addresses
Thomas D. Nadeau (editor)
BT
BT Centre
81 Newgate Street
London EC1A 7AJ
United Kingdom
EMail: tom.nadeau@bt.com
David Zelig (editor)
Oversi Networks
1 Rishon Letzion St.
Petah Tikva
Israel
Phone: +972 77 3337 750
EMail: davidz@oversi.com
Orly Nicklass (editor)
RADVISION
24 Raul Wallenberg
Tel Aviv
Phone: +972 3 776 9444
EMail: orlyn@radvision.com
AI ELI5
On this page
§1What This Module Is For
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols. It holds textual conventions (TCs) used for pseudowire (PW) technology and for Pseudowire Edge-to-Edge Emulation (PWE3) MIB modules. The abstract states the intent: these TCs are to be imported and used in PW-related MIB modules that would otherwise define their own representations.
The module is named PW-TC-STD-MIB and its identity is pwTcStdMIB, registered as { mib-2 188 }. It was last updated on 21 April 2009 and has one revision, the original version.
Pseudowire documents keep needing the same kinds of labels. This note writes those labels down once so everyone can reuse them.
§2The Management Framework
Managed objects are reached through a virtual information store called the Management Information Base. Objects are generally accessed through the Simple Network Management Protocol (SNMP) and defined using the Structure of Management Information (SMI). This module is compliant with SMIv2, described in RFC 2578, RFC 2579 and RFC 2580 (all STD 58). For the overall framework the RFC points to section 7 of RFC 3410.
A textual convention gives a name and a precise meaning to a basic type, so that many objects can share it. The module imports MODULE-IDENTITY, Unsigned32 and mib-2 from SNMPv2-SMI, and TEXTUAL-CONVENTION from SNMPv2-TC.
Network gear keeps a big notebook of facts about itself. This note defines some standard ways of writing certain facts in that notebook.
§3Identifiers and Index Types
Several conventions are plain Unsigned32 values with a display hint of d (decimal).
PwGroupID: an administrative identification for grouping a set of service-specific pseudowire services.PwIDType: the pseudowire identifier, used together with other fields to identify the PW in the signaling session.PwIndexType: a unique value greater than zero for each locally defined PW, used to index MIB tables. Values are recommended to be assigned contiguously from 1, and the value for each PWMUSTstay constant at least from one re-initialization to the next.PwIndexOrZeroType: the same, but also allows zero. The meaning of zero is object-specific and must be defined by each object that uses it, for example when the PW is unknown or when none or all PWs are meant.PwCfgIndexOrzero: an index into configuration tables for technology-specific information; zero means no additional configuration applies.
Two more identify attachments in generalized FEC signaling: PwAttachmentIdentifierType, an octet string of 0 to 255 octets where a NULL identifier has zero length, and PwGenIdType, a value from 0 to 254 for the Attachment Group Identifier and Attachment Individual Identifier types.
These are like ticket numbers. Each pseudowire gets its own number so tables can point to it, and zero can be used to mean 'none' or 'not known'.
§4Status Conventions
PwOperStatusTC gives the operational status of a PW as an integer: up(1) ready to pass packets, down(2) signaling not finished or service-level indications say it is not passing packets, testing(3) admin status set to test, dormant(4) pending an external event, notPresent(5) a component is missing (configuration error, incomplete configuration or missing hardware), and lowerLayerDown(6) lower-layer interfaces for the underlying PSN are not up.
PwStatus is a set of bits for faults affecting the PW and its interfaces: pwNotForwarding(0), servicePwRxFault(1), servicePwTxFault(2), psnPwRxFault(3) and psnPwTxFault(4). If no bits are set, no faults are reported.
Like a traffic light with extra notes: working, not working yet, being tested, waiting, or missing a part. A separate set of flags says what kind of fault was seen.
- 1up — Ready to pass packets.
- 2down — Signaling not finished, or the PW is not passing packets.
- 3testing — AdminStatus at the PW level is set to test.
- 4dormant — Pending, waiting for an external event.
- 5notPresent — A component needed to set up the PW is missing.
- 6lowerLayerDown — Lower-layer interfaces for the PSN are not up.
§5Control Word and Fragmentation Conventions
PwCwStatusTC reports how control word (CW) negotiation stands, based on local configuration and what the peer indicated. Its values are waitingForNextMsg(1), sentWrongBitErrorCode(2), rxWithdrawWithWrongBitErrorCode(3), illegalReceivedBit(4), cwPresent(5), cwNotPresent(6) and notYetKnown(7). It cites RFC 4447.
For fragmentation, PwFragSize is the desired fragmentation length in bytes, where zero means fragmentation is not desired for packets bound for the PSN. PwFragStatus is a bit set: noFrag(0), cfgFragGreaterThanPsnMtu(1), cfgFragButRemoteIncapable(2), remoteFragCapable(3) and fragEnabled(4). Fragmentation will be used only if the local node is configured for it, the peer can accept fragmented packets and the CW is in use. It cites RFC 4623.
Two ends must agree on a few options first. These labels record whether they have agreed yet, and whether big packets will be cut into smaller pieces.
§6Security and IANA
The module defines no management objects, only textual conventions that other PWE3 MIB modules may use. The RFC says meaningful security considerations can only be written in the MIB modules that define management objects, so this document has no impact on the security of the Internet.
For IANA, the module uses one object identifier value recorded in the SMI Numbers registry: pwTcStdMIB is { mib-2 188 }.
This note only provides labels and does not control anything, so it has no security risks by itself. The documents that use the labels must handle security.