MPLS Fault Management Operations, Administration, and Maintenance (OAM)
draft-ietf-mpls-tp-fault-07
The information below is for an old version of the document that is already published as an RFC.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 6427.
|
|
|---|---|---|---|
| Authors | Martin Vigoureux , David Ward , George Swallow , Sami Boutros , Annamaria Fulignoli | ||
| Last updated | 2015-10-14 (Latest revision 2011-09-02) | ||
| Replaces | draft-boutros-mpls-tp-fault, draft-sfv-mpls-tp-fault | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 6427 (Proposed Standard) | |
| Action Holders |
(None)
|
||
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | Adrian Farrel | ||
| IESG note | |||
| Send notices to | (None) |
draft-ietf-mpls-tp-fault-07
MPLS Working Group G. Swallow, Ed.
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track A. Fulignoli, Ed.
Expires: March 5, 2012 Ericsson
M. Vigoureux, Ed.
Alcatel-Lucent
S. Boutros
Cisco Systems, Inc.
D. Ward
Juniper Networks, Inc.
September 2, 2011
MPLS Fault Management OAM
draft-ietf-mpls-tp-fault-07
Abstract
This document specifies Operations, Administration, and Maintenance
messages to indicate service disruptive conditions for MPLS based
Transport Network Label Switched Paths. The notification mechanism
employs a generic method for a service disruptive condition to be
communicated to a Maintenance Entity Group End Point. This document
defines an MPLS OAM channel, along with messages to communicate
various types of service disruptive conditions.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 5, 2012.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. MPLS Fault Management Messages . . . . . . . . . . . . . . . . 5
2.1. MPLS Alarm Indication Signal . . . . . . . . . . . . . . . 5
2.1.1. MPLS Link Down Indication . . . . . . . . . . . . . . 6
2.2. MPLS Lock Report . . . . . . . . . . . . . . . . . . . . . 6
2.3. Propagation of MPLS Fault Messages . . . . . . . . . . . . 7
3. MPLS Fault Management Channel . . . . . . . . . . . . . . . . 7
4. MPLS Fault Management Message Format . . . . . . . . . . . . . 7
4.1. Fault Management Message TLVs . . . . . . . . . . . . . . 9
4.1.1. Interface Identifier TLV . . . . . . . . . . . . . . . 10
4.1.2. Global Identifier . . . . . . . . . . . . . . . . . . 10
5. Sending and Receiving Fault Management Messages . . . . . . . 11
5.1. Sending a Fault Management Message . . . . . . . . . . . . 11
5.2. Clearing a FM Indication . . . . . . . . . . . . . . . . . 11
5.3. Receiving a FM Indication . . . . . . . . . . . . . . . . 11
6. Minimum Implementation Requirements . . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8.1. Pseudowire Associated Channel Type . . . . . . . . . . . . 13
8.2. MPLS Fault OAM Message Type Registry . . . . . . . . . . . 14
8.3. MPLS Fault OAM Flag Registry . . . . . . . . . . . . . . . 14
8.4. MPLS Fault OAM TLV Registry . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
Proper operation of a transport network depends on the ability to
quickly identify faults and focus attention on the root cause of the
disruption. This document defines MPLS Fault Management Operations,
Administration, and Maintenance (OAM) messages. When a fault occurs
in a server (sub-)layer, Fault Management OAM messages are sent to
clients of that server so that alarms, which otherwise would be
generated by the subsequent disruption of the clients, may be
suppressed. This prevents a storm of alarms and allows operations to
focus on the actual faulty elements of the network.
In traditional transport networks, circuits such as T1 lines are
typically provisioned on multiple switches. When an event that
causes disruption occurs on any link or node along the path of such a
transport circuit, OAM indications are generated. When received,
these indications may be used to suppress alarms and/or activate a
backup circuit. The MPLS based Transport Network provides mechanisms
equivalent to traditional transport circuits. Therefore a Fault
Management (FM) capability must be defined for MPLS. This document
defines FM capabilities to meet the MPLS-TP requirements as described
in RFC 5654 [1], and the MPLS-TP Operations, Administration, and
Maintenance Requirements as described in RFC 5860 [2]. These
mechanisms are intended to be applicable to other aspects of MPLS as
well. However, applicability to other types of LSPs is beyond the
scope of this document.
Two broad classes of service disruptive conditions are identified.
1. Fault: The inability of a function to perform a required action.
This does not include an inability due to preventive maintenance,
lack of external resources, or planned actions.
2. Lock: an administrative status in which it is expected that only
test traffic, if any, and OAM (dedicated to the LSP) can be sent
on an LSP.
Within this document a further term is defined, server-(sub-)layer-
failure, or more briefly server-failure. A server-failure occurs
when a fault condition or conditions have persisted long enough to
consider the required service function to have terminated. In the
case of a protected server, this would mean that both the working and
and any protection facilities have suffered faults of the required
duration.
This document specifies an MPLS OAM channel called an "MPLS-OAM Fault
Management (FM)" channel. A single message format and a set of
procedures are defined to communicate service disruptive conditions
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from the location where they occur to the endpoints of LSPs which are
affected by those conditions. Multiple message types and flags are
used to indicate and qualify the particular condition.
Corresponding to the two classes of service disruptive conditions
listed above, two messages are defined to communicate the type of
condition. These are known as:
Alarm Indication Signal (AIS)
Lock Report (LKR)
1.1. Terminology
ACH: Associated Channel Header
ACh: Associated Channel
CC: Continuity Check
FM: Fault Management
GAL: Generic Associated Channel Label
LOC: Loss of Continuity
LSP: Label Switched Path
MEP: Maintenance Entity Group End Point
MPLS: Multi-Protocol Label Switching
MPLS-TP: MPLS Transport Profile
MS-PW: Multi-Segment Pseudowire
OAM: Operations, Administration, and Maintenance
PHP: Penultimate Hop Pop
PW: Pseudowire
TLV: Type, Length, Value
1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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document are to be interpreted as described in RFC 2119 [3].
2. MPLS Fault Management Messages
This document defines two messages to indicate service disruptive
conditions, Alarm Indication Signal, and Lock Report. The semantics
of the individual messages are described in subsections below. Fault
OAM messages are applicable to LSPs used in the MPLS Transport
Profile. Such LSPs are bound to specific server layers based upon
static configuration or signaling in a client/server relationship.
Fault Management messages are carried in-band of the client LSP or
MS-PW by using the Associated Channel Header (ACH). For LSPs other
than PWs, the ACH is identified by the Generic Associated Channel
Label (GAL) as defined in RFC5586 [4]. To facilitate recognition and
delivery of Fault Management messages, the Fault Management Channel
is identified by a unique Associated Channel (ACh) codepoint.
Fault OAM messages are generated by intermediate nodes where a client
LSP is switched. When a server (sub-)layer, (e.g. a link or
bidirectional LSP) used by the client LSP fails, the intermediate
node sends Fault Management messages downstream towards the endpoint
of the LSP. The messages are sent to the client MEPs by inserting
them into the affected client LSPs in the direction downstream of the
fault location. These messages are sent periodically until the
condition is cleared.
2.1. MPLS Alarm Indication Signal
The MPLS Alarm Indication Signal (AIS) message is generated in
response to detecting faults in the server (sub-)layer. The AIS
message SHOULD be sent as soon as the condition is detected, but MAY
be delayed owing to processing in an implementation, and MAY be
suppressed if protection is achieved very rapidly. For example, an
AIS message may be sent during a protection switching event and would
cease being sent (or cease being forwarded by the protection switch
selector) if the protection switch was successful in restoring the
link. However, an implementation may instead wait to see if the
protection switch is successful prior to sending any AIS messages.
The primary purpose of the AIS message is to suppress alarms in the
layer network above the level at which the fault occurs. When the
Link Down Indication is set, the AIS message MAY be used to trigger
recovery mechanisms.
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2.1.1. MPLS Link Down Indication
The Link Down Indication (LDI) is communicated by setting the L-flag
to 1. A node sets the L-flag in the AIS message in response to
detecting a failure in the server layer. A node MUST NOT set the
L-flag until the fault has been determined to be a server-failure. A
node MUST set the L-flag if the fault has been determined to be a
server-failure. For example during a server layer protection
switching event, a node MUST NOT set the L-flag. However if the
protection switch was unsuccessful in restoring the link within the
expected repair time, the node MUST set the L-flag.
The setting of the L-flag can be predetermined based on the
protection state. For example, if a server layer is protected and
both the working and protection paths are available, the node should
send AIS with the L-flag clear upon detecting a fault condition. If
the server layer is unprotected or the server layer is protected but
only the active path is available, the node should send AIS with the
L-flag set upon detecting a loss of continuity (LOC) condition. Note
again that the L-flag is not set until a server-failure has been
declared. Thus if there is any hold-off timer associated with the
LOC, then the L-flag is not set until that timer has expired.
The receipt of an AIS message with the L-flag set MAY be treated as
the equivalent of LOC at the client layer. The choice of treatment
is related to the rate at which the Continuity Check (CC) function is
running. In a normal transport environment, CC is run at a high rate
in order to detect a failure within 10s of milliseconds. In such an
environment, the L-flag MAY be ignored and the AIS message is used
solely for alarm suppression.
In more general MPLS environments the CC function may be running at a
much slower rate. In this environment, the Link Down Indication
enables faster switch-over upon a failure occurring along the client
LSP.
2.2. MPLS Lock Report
The MPLS Lock Report (LKR) message is generated when a server
(sub-)layer entity has been administratively locked. Its purpose is
to communicate the locked condition to the client layer entities.
When a server layer is administratively locked it is not available to
carry client traffic. The purpose of the LKR message is to suppress
alarms in the layer network above the level at which the
administrative lock occurs and to allow the clients to differentiate
the lock condition from a fault condition. While the primary purpose
of the LKR message is to suppress alarms, similar to AIS with the LDI
(L-flag set), the receipt of an LKR message MAY be treated as the
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equivalent of loss of continuity at the client layer.
2.3. Propagation of MPLS Fault Messages
MPLS-TP allows for a hierarchy of LSPs. When the client MEP of an
LSP which is also acting as a server layer receives FM indications,
the following rules apply. If the CC function is disabled for the
server LSP, a node SHOULD generate AIS messages toward any clients
when either the AIS or LKR indication is raised. Note that the
L-flag is not automatically propagated. The rules of Section 2.1.1
apply. In particular, the L-flag is not set until a server-failure
has been declared.
3. MPLS Fault Management Channel
The MPLS Fault Management channel is identified by the ACH as defined
in RFC 5586 [4] with the Associated Channel Type set to the MPLS
Fault Management (FM) code point = 0xHHHH. [HHHH to be assigned by
IANA from the PW Associated Channel Type registry.] The FM Channel
does not use ACh TLVs and MUST NOT include the ACh TLV header. The
ACH with the FM ACh code point is shown below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | 0xHHHH FM Channel |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ~
~ MPLS Fault Management Message ~
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: ACH Indication of the MPLS Fault Management Channel
The first three fields are defined in RFC 5586 [4].
The Fault Management Channel is 0xHHHH (to be assigned by IANA).
4. MPLS Fault Management Message Format
The format of the Fault Management message is shown below.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vers | Resvd | Msg Type | Flags | Refresh Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Total TLV Len | ~
+-+-+-+-+-+-+-+-+ TLVs ~
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: MPLS Fault OAM Message Format
Version
The Version Number is currently 1.
Reserved
This field MUST be set to zero on transmission and ignored on
receipt.
Message Type
The Message Type indicates the type of condition as listed in the
table below.
Msg Type Description
-------- -----------------------------
0x0 Reserved
0x1 Alarm Indication Signal (AIS)
0x2 Lock Report (LKR)
Flags
Two flags are defined. The reserved flags in this field MUST be
set to zero on transmission and ignored on receipt.
+-+-+-+-+-+-+-+-+
| Reserved |L|R|
+-+-+-+-+-+-+-+-+
Figure 3: Flags
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L-flag
Link Down Indication. The L-flag only has significance in the
AIS message. For the LKR message the L-flag MUST be set to
zero and ignored on receipt. See Section 2.1.1 for details on
setting this bit.
R-flag
The R-flag is clear to indicate the presence of an FM condition
and is to one to indicate the removal of a previously sent FM
condition.
Refresh Timer
The maximum time between successive FM messages specified in
seconds. The range is 1 to 20. The value 0 is not permitted.
Total TLV Length
The total length in bytes of all included TLVs.
4.1. Fault Management Message TLVs
TLVs are used in Fault Management messages to carry information that
may not pertain to all messages as well as to allow for
extensibility. The TLVs currently defined are the IF_ID, and the
Global_ID.
TLVs (Type-Length-Value tuples) have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ .
| .
. Value .
. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Fault TLV Format
Type
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Encodes how the Value field is to be interpreted.
Length
Specifies the length of the Value field in octets.
Value
Octet string of Length octets that encodes information to be
interpreted as specified by the Type field.
4.1.1. Interface Identifier TLV
The Interface Identifier (IF_ID) TLV carries the IF_ID as defined in
draft-ietf-mpls-tp-identifiers [5]. The Type is 0x1. The length is
0x8.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MPLS-TP Node Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MPLS-TP Interface Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Interface Identifier TLV Format
4.1.2. Global Identifier
The Global Identifier (Global_ID) TLV carries the Global_ID as
defined in draft-ietf-mpls-tp-identifiers [5]. The Type is 0x2. The
length is 0x4.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MPLS-TP Global Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Global Identifier TLV Format
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5. Sending and Receiving Fault Management Messages
5.1. Sending a Fault Management Message
Service disruptive conditions are indicated by sending FM messages.
The message type is set to the value corresponding to the condition.
The refresh timer is set to the maximum time between successive FM
messages. This value MUST NOT be changed on successive FM messages
reporting the same incident. If the optional clearing procedures are
not used, then the default value is 1 second. Otherwise the default
value is 20 seconds.
A Global_ID MAY be included. If the R-flag clearing procedures are
to be used, the IF_ID TLV MUST be included. Otherwise, the IF_ID TLV
MAY be included.
The message is then sent. Assuming the condition persists, the
message MUST be retransmitted two more times at an interval of one
second. Further retransmissions are made according to the value of
the refresh timer. Retransmissions continue until the condition is
cleared.
5.2. Clearing a FM Indication
When a fault is cleared, a node MUST cease sending the associated FM
messages. Ceasing to send FM messages will clear the indication
after 3.5 times the refresh timer. To clear an indication more
quickly, the following procedure is used. The R-flag of the FM
message is set to one. Other fields of the FM message SHOULD NOT be
modified. The message is sent immediately and then retransmitted two
more times at an interval of one second. Note, however if another
fault occurs, the node MUST cease these retransmissions and a
generate new FM messages for the new fault.
5.3. Receiving a FM Indication
When a FM message is received, a MEP examines it to ensure that it is
well formed. If the message type is reserved or unknown, the message
is ignored. If the version number is unknown, the message is
ignored.
If the R-flag is set to zero, the MEP checks to see if a condition
matching the message type exists. If it does not, the condition
specific to the message type is entered. An expiration-timer is set
to 3.5 times the refresh timer. If the message type matches an
existing condition, the message is considered a refresh and the
expiration-timer is reset. In both cases, if an IF_ID tlv is
present, it is recorded.
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If the R-flag is set to one, the MEP checks to see if a condition
matching the message type and IF_ID exists. If it does, that
condition is cleared. Otherwise the message is ignored.
If the expiration-time expires, the condition is cleared.
6. Minimum Implementation Requirements
At a minimum an implementation MUST support the following:
1. Sending AIS and LKR messages at a rate of 1 per second.
2. Support of setting the L-flag to indicate a server-failure.
3. Receiving AIS and LKR messages with any allowed Refresh Timer
value.
The following items are OPTIONAL to implement.
1. Sending AIS and LKR message with values of the Refresh Timer
other than 1 second.
2. Support of receiving the L-flag.
3. Support of setting the R-flag to a value other than zero.
4. Support of receiving the R-flag.
5. All TLVs.
7. Security Considerations
MPLS-TP is a subset of MPLS and so builds upon many of the aspects of
the security model of MPLS. MPLS networks make the assumption that
it is very hard to inject traffic into a network, and equally hard to
cause traffic to be directed outside the network. The control plane
protocols utilize hop-by-hop security, and assume a "chain-of-trust"
model such that end-to-end control plane security is not used. For
more information on the generic aspects of MPLS security, see RFC
5920 [8].
This document describes a protocol carried in the G-ACh RFC 5586 [4],
and so is dependent on the security of the G-ACh, itself. The G-ACh
is a generalization of the Associated Channel defined in RFC 4385
[6]. Thus, this document relies heavily on the security mechanisms
provided for the Associated Channel and described in those two
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documents.
A specific concern for the G-ACh is that is can be used to provide a
covert channel. This problem is wider than the scope of this
document and does not need to be addressed here, but it should be
noted that the channel provides end-to-end connectivity and SHOULD
NOT be policed by transit nodes. Thus, there is no simple way of
preventing any traffic being carried in the G-ACh between consenting
nodes.
A good discussion of the data plane security of an associated channel
may be found in RFC 5085 [9]. That document also describes some
mitigation techniques.
It should be noted that the G-ACh is essentially connection-oriented
so injection or modification of control messages specified in this
document requires the subversion of a transit node. Such subversion
is generally considered hard in MPLS networks, and impossible to
protect against at the protocol level. Management level techniques
are more appropriate.
Spurious fault OAM messages form a vector for a denial of service
attack. However, since these messages are carried in a control
channel, except for one case discussed below, one would have to gain
access to a node providing the service in order to effect such an
attack. Since transport networks are usually operated as a walled
garden, such threats are less likely.
If external MPLS traffic is mapped to an LSP via a PHP forwarding
operation, it is possible to insert a GAL followed by a fault OAM
message. In such a situation an operator SHOULD protect against this
attack by filtering any fault OAM messages with the GAL at the top of
the label stack.
8. IANA Considerations
8.1. Pseudowire Associated Channel Type
Fault OAM requires a unique Associated Channel Type which are
assigned by IANA from the Pseudowire Associated Channel Types
Registry.
Registry:
Value Description TLV Follows Reference
----------- ----------------------- ----------- ---------
0xHHHH Fault OAM No (This Document)
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[Note: An early codepoint allocation was made: 0x0058 Fault OAM
(TEMPORARY - expires 2012-07-20)]
8.2. MPLS Fault OAM Message Type Registry
This section details the MPLS Fault OAM Message Type Registry, a new
name space to be managed by IANA. The Type space is divided into
assignment ranges; the following terms are used in describing the
procedures by which IANA allocates values: "Standards Action" (as
defined in RFC 5226 [7]) and "Experimental Use".
MPLS Fault OAM Message Types take values in the range 0-255.
Assignments in the range 0-251 are via Standards Action; values in
the range 252-255 are for Experimental Use, and MUST NOT be
allocated.
Message Types defined in this document are:
Msg Type Description
-------- -----------------------------
0x0 Reserved (not available for allocation)
0x1 Alarm Indication Signal (AIS)
0x2 Lock Report (LKR)
8.3. MPLS Fault OAM Flag Registry
This section details the MPLS Fault OAM Flag Registry, a new name
space to be managed by IANA. The Flag space ranges from 0-7. All
flags are allocated by "Standards Action".
Flags defined in this document are:
Bit Hex Value Description
--- --------- -----------
0-5 Unassigned
6 0x2 L-Flag
7 0x1 R-Flag
8.4. MPLS Fault OAM TLV Registry
This sections details the MPLS Fault OAM TLV Registry, a new name
spaces to be managed by IANA. The Type space is divided into
assignment ranges; the following terms are used in describing the
procedures by which IANA allocates values: "Standards Action" (as
defined in RFC 5226 [7]), "Specification Required" and "Private Use".
MPLS Fault OAM TLVs which take values in the range 0-255.
Assignments in the range 0-191 are via Standards Action; assignments
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in the range 192-247 are made via "Specification Required"; values in
the range 248-255 are for Experimental Use, and MUST NOT be
allocated.
TLVs defined in this document are:
Value TLV Name
----- -------
0 Reserved (not available for allocation)
1 Interface Identifier TLV
2 Global Identifier
9. References
9.1. Normative References
[1] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S.
Ueno, "Requirements of an MPLS Transport Profile", RFC 5654,
September 2009.
[2] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Operations, Administration, and Maintenance (OAM) in MPLS
Transport Networks", RFC 5860, May 2010.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[4] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
Associated Channel", RFC 5586, June 2009.
[5] Bocci, M., Swallow, G., and E. Gray, "MPLS-TP Identifiers",
draft-ietf-mpls-tp-identifiers-07 (work in progress), July 2011.
[6] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
"Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use
over an MPLS PSN", RFC 4385, February 2006.
[7] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
9.2. Informative References
[8] Fang, L., "Security Framework for MPLS and GMPLS Networks",
RFC 5920, July 2010.
[9] Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit
Connectivity Verification (VCCV): A Control Channel for
Swallow, et al. Expires March 5, 2012 [Page 15]
Internet-Draft MPLS Fault Management OAM September 2011
Pseudowires", RFC 5085, December 2007.
Authors' Addresses
George Swallow (editor)
Cisco Systems, Inc.
300 Beaver Brook Road
Boxborough, Massachusetts 01719
United States
Email: swallow@cisco.com
Annamaria Fulignoli (editor)
Ericsson
Email: annamaria.fulignoli@ericsson.com
Martin Vigoureux (editor)
Alcatel-Lucent
Route de Villejust
Nozay, 91620
France
Email: martin.vigoureux@alcatel-lucent.com
Sami Boutros
Cisco Systems, Inc.
3750 Cisco Way
San Jose, California 95134
USA
Email: sboutros@cisco.com
David Ward
Juniper Networks, Inc.
Email: dward@juniper.net
Swallow, et al. Expires March 5, 2012 [Page 16]
Internet-Draft MPLS Fault Management OAM September 2011
Stewart Bryant
Cisco Systems, Inc.
250, Longwater
Green Park, Reading RG2 6GB
UK
Email: stbryant@cisco.com
Siva Sivabalan
Cisco Systems, Inc.
2000 Innovation Drive
Kanata, Ontario K2K 3E8
Canada
Email: msiva@cisco.com
Swallow, et al. Expires March 5, 2012 [Page 17]