draft-ietf-mpls-tp-fault-01.txt   draft-ietf-mpls-tp-fault-02.txt 
MPLS Working Group G. Swallow, Ed. MPLS Working Group G. Swallow, Ed.
Internet-Draft Cisco Systems, Inc. Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track A. Fulignoli, Ed. Intended status: Standards Track A. Fulignoli, Ed.
Expires: September 9, 2010 Ericsson Expires: January 6, 2011 Ericsson
M. Vigoureux, Ed. M. Vigoureux, Ed.
Alcatel-Lucent Alcatel-Lucent
S. Boutros
Cisco Systems, Inc.
D. Ward
Juniper Networks, Inc.
March 8, 2010 July 5, 2010
MPLS Fault Management OAM MPLS Fault Management OAM
draft-ietf-mpls-tp-fault-01 draft-ietf-mpls-tp-fault-02
Abstract Abstract
This draft specifies OAM messages to indicate service disruptive This draft specifies OAM messages to indicate service disruptive
conditions for MPLS Transport Profile (MPLS-TP) Label Switched Paths conditions for MPLS Transport Profile (MPLS-TP) Label Switched Paths
(LSPs). The notification mechanism employs a generic method for a (LSPs). The notification mechanism employs a generic method for a
service disruptive condition to be communicated to a Maintenance End service disruptive condition to be communicated to a Maintenance End
Point (MEP). An MPLS Operation, Administration, and Maintenance Point (MEP). An MPLS Operation, Administration, and Maintenance
(OAM) channel is defined along with messages to communicate various (OAM) channel is defined along with messages to communicate various
types of service disruptive conditions. types of service disruptive conditions.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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The list of current Internet-Drafts can be accessed at This Internet-Draft will expire on January 6, 2011.
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This Internet-Draft will expire on September 9, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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described in the BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. MPLS Fault Management Messages . . . . . . . . . . . . . . . . 5 2. MPLS Fault Management Messages . . . . . . . . . . . . . . . . 4
2.1. MPLS-TP Alarm Indication Signal . . . . . . . . . . . . . 6 2.1. MPLS-TP Alarm Indication Signal . . . . . . . . . . . . . 5
2.2. MPLS-TP Link Down Indication . . . . . . . . . . . . . . . 6 2.1.1. MPLS-TP Link Down Indication . . . . . . . . . . . . . 5
2.3. The Relationship of AIS to LDI . . . . . . . . . . . . . . 7 2.2. MPLS-TP Lock Report . . . . . . . . . . . . . . . . . . . 6
2.4. MPLS-TP Locked Report . . . . . . . . . . . . . . . . . . 7 3. MPLS Fault Management Channel . . . . . . . . . . . . . . . . 6
3. MPLS Fault Management Channel . . . . . . . . . . . . . . . . 7 4. MPLS Fault Management Message Format . . . . . . . . . . . . . 6
4. MPLS Fault Management Message Format . . . . . . . . . . . . . 8 4.1. Fault Management Message TLVs . . . . . . . . . . . . . . 8
5. Sending and Receiving Fault Management Messages . . . . . . . 9 4.1.1. Interface Identifier TLV . . . . . . . . . . . . . . . 9
5.1. Sending a Fault Management Message . . . . . . . . . . . . 9 4.1.2. Global Identifier . . . . . . . . . . . . . . . . . . 9
4.1.3. International Carrier Code . . . . . . . . . . . . . . 9
5. Sending and Receiving Fault Management Messages . . . . . . . 10
5.1. Sending a Fault Management Message . . . . . . . . . . . . 10
5.2. Clearing a FM Indication . . . . . . . . . . . . . . . . . 10 5.2. Clearing a FM Indication . . . . . . . . . . . . . . . . . 10
5.3. Receiving a FM Indication . . . . . . . . . . . . . . . . 10 5.3. Receiving a FM Indication . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.1. Pseudowire Associated Channel Type . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . . 10 7.2. MPLS Fault OAM Message Type Registry . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . . 11 7.3. MPLS Fault OAM TLV Registry . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
In traditional transport networks, circuits such as T1 lines are In traditional transport networks, circuits such as T1 lines are
provisioned on multiple switches. When a disruption occurs on any provisioned on multiple switches. When a disruption occurs on any
link or node along the path of such a transport circuit, alarms are link or node along the path of such a transport circuit, OAM are
generated which may in turn suppress alarms and/or activate a backup generated which may in turn suppress alarms and/or activate a backup
circuit. The MPLS Transport Profile (MPLS-TP) provides mechanisms to circuit. The MPLS Transport Profile (MPLS-TP) provides mechanisms to
emulate traditional transport circuits. Therefore a Fault Management emulate traditional transport circuits. Therefore a Fault Management
(FM) capability must be defined for MPLS. This capability is being (FM) capability must be defined for MPLS. This capability is being
defined to meet the MPLS-TP requirements as defined in RFC 5654 [1], defined to meet the MPLS-TP requirements as defined in RFC 5654 [1],
and the MPLS-TP Operations, Administration and Maintenance and the MPLS-TP Operations, Administration and Maintenance
Requirements as defined in draft-ietf-mpls-tp-oam-requirements [2]. Requirements as defined in RFC 5860 [2]. However, this mechanism is
However, this mechanism is intended to be applicable to other aspects intended to be applicable to other aspects of MPLS as well.
of MPLS as well.
Three broad classes service disruptive conditions are identified. Two broad classes service disruptive conditions are identified.
1. Defect: the situation in which the density of anomalies has 1. Defect: the situation in which the density of anomalies has
reached a level where the ability to perform a required function reached a level where the ability to perform a required function
has been interrupted. has been interrupted.
2. Fault: the inability of a function to perform a required action. 2. Lock: an administrative status in which it is expected that only
This does not include an inability due to preventive maintenance, test traffic, if any, and OAM (dedicated to the LSP) can be sent
lack of external resources, or planned actions (e.g., on an LSP.
Administrative Locking). A fault is a persistent defect.
3. Lock: an administrative status in which it is expected that only Within the Defect class, a further category, Fault is identified. A
test traffic, if any, and OAM (dedicated to the LSP) can be fault is the inability of a function to perform a required action. A
mapped on an LSP. fault is a persistent defect.
This document specifies an MPLS OAM channel called an "MPLS-OAM Fault This document specifies an MPLS OAM channel called an "MPLS-OAM Fault
Management (FM)" channel. A single message format and a set of Management (FM)" channel. A single message format and a set of
procedures are defined to communicate service disruptive conditions procedures are defined to communicate service disruptive conditions
from the location where they occur to the endpoints of LSPs which are from the location where they occur to the endpoints of LSPs which are
affected by those conditions. Multiple message types are used to affected by those conditions. Multiple message types and flags are
indicate the particular condition. used to indicate and qualify the particular condition.
Corresponding to the three classes of service disruptive conditions Corresponding to the three classes of service disruptive conditions
listed above, three messages are defined to communicate the type of listed above, two messages are defined to communicate the type of
condition. These are known as: condition. These are known as:
Alarm Indication Signal (AIS) Alarm Indication Signal (AIS)
Link Down Indication (LDI) Lock Report (LKR)
Locked Report (LKR)
1.1. Terminology 1.1. Terminology
ACH: Associated Channel Header ACH: Associated Channel Header
AII: Attachment Interface Identifier
ASN: Autonomous System Number ASN: Autonomous System Number
FEC: Forwarding Equivalence Class
FM: Fault Management FM: Fault Management
GAL: Generic Associated Channel Label
LSP: Label Switched Path LSP: Label Switched Path
LSR: Label Switching Router LSR: Label Switching Router
MEP: Maintenance End Point MEP: Maintenance End Point
MIP: Maintenance Intermediate Point MIP: Maintenance Intermediate Point
MPLS: Multi-Protocol Label Switching MPLS: Multi-Protocol Label Switching
skipping to change at page 5, line 51 skipping to change at page 4, line 42
TTL: Time To Live TTL: Time To Live
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [3]. document are to be interpreted as described in RFC 2119 [3].
2. MPLS Fault Management Messages 2. MPLS Fault Management Messages
This document defines messages to indicate three types of service This document defines messages to indicate service disruptive
disruptive conditions, Alarm Indication Signal, Link Down Indication, conditions. Two messages are defined Alarm Indication Signal, and
and Locked Report. These semantics of the individual messages are Lock Report. These semantics of the individual messages are
described in subsections below. Although only one of the conditions described in subsections below.
is named "Fault", we use the term "Fault Management" to generically
mean management of all three conditions.
Fault Management messages are carried in-band by using the Associated Fault Management messages are carried in-band by using the Associated
Channel Header (ACH) and Generic Associated Channel Label (GAL) as Channel Header (ACH) and Generic Associated Channel Label (GAL) as
defined in RFC5586 [4]. To facilitate recognition and delivery of defined in RFC5586 [4]. To facilitate recognition and delivery of
Fault Management messages, the Fault Management Channel is identified Fault Management messages, the Fault Management Channel is identified
by a unique codepoint. by a unique ACH codepoint.
When a server MEP detects a service disruptive condition, Fault Fault OAM messages are generated by intermediate nodes where an LSP
Management messages are generated by the convergence server-to-client is switched. When a server layer, (e.g. a link) used by the LSP
adaptation function. The messages are sent to the client MEPs by fails, the intermediate node sends Fault Management messages using
inserting them into the affected LSPs in the direction opposite to the LSP's Fault associated channel back to the endpoint of the LSP.
the detecting MEP's peer server MEP(s). The message is sent Strictly speaking, when a server MEP detects a service disruptive
periodically until the condition is cleared. condition, Fault Management messages are generated by the convergence
server-to-client adaptation function. The messages are sent to the
client MEPs by inserting them into the affected LSPs in the direction
opposite to the detecting MEP's peer server MEP(s). The message is
sent periodically until the condition is cleared.
2.1. MPLS-TP Alarm Indication Signal 2.1. MPLS-TP Alarm Indication Signal
The MPLS-TP Alarm Indication Signal (AIS) message is generated in The MPLS-TP Alarm Indication Signal (AIS) message is generated in
response to detecting defects in the server layer. The AIS message response to detecting defects in the server layer. The AIS message
SHOULD be sent as soon is the condition is detected, that is before SHOULD be sent as soon as the condition is detected, that is before
any determination has been made as to whether the condition is fatal. any determination has been made as to whether the condition is
For example an AIS message may be sent during a protection switching persistent and therefore fatal. For example, an AIS message may be
event and would cease being sent if the protection switch was sent during a protection switching event and would cease being sent
successful in restoring the link. (or cease being forwarded by the protection switch selector) if the
protection switch was successful in restoring the link.
Its primary purpose is to suppress alarms in the MPLS-TP layer Its primary purpose is to suppress alarms in the MPLS-TP layer
network above the level at which the defect occurs. The AIS message network above the level at which the defect occurs. The AIS message
MAY be used to trigger recovery mechanisms. It should be noted that MAY be used to trigger recovery mechanisms. It should be noted that
such use would be subject to false positives, e.g. unnecessary such use would be subject to false positives, e.g. unnecessary
protection switching events in the client layer. protection switching events in the client layer.
2.2. MPLS-TP Link Down Indication 2.1.1. MPLS-TP Link Down Indication
The LDI message is generated in response to detecting a fatal failure
in the server layer. The LDI message MUST NOT be sent until the
defect has been determined to be fatal. For example during a
protection switching event LDI messages are not sent. However if the
protection switch was unsuccessful in restoring the link within the
expected repair time, an LDI message MUST be sent.
The receipt of an LDI message MAY be treated as the equivalent of The LDI flag is set in response to detecting a fatal failure in the
loss of continuity at the client layer. Like AIS it also is used to server layer. The LDI flag MUST NOT be set until the defect has been
suppress alarms. determined to be fatal. For example during a protection switching
event the LDI flag is not set. However if the protection switch was
unsuccessful in restoring the link within the expected repair time,
the LDI flag MUST be set.
2.3. The Relationship of AIS to LDI The receipt of an AIS message with the LDI flag set MAY be treated as
the equivalent of loss of continuity 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, AIS messages with the LDI flag
set should be treated the same as any other AIS message, that is,
used solely for alarm suppression.
AIS and LDI are closely related functions and also related to the In more general MPLS environments the CC function may be running at a
rate at which the Continuity Check (CC) function is running. In a much slower rate. In this environment, the LDI flag enables faster
normal transport environment, CC is run at a high rate in order to switch-over upon a failure occurring along the LSP.
detect a failure within 10s of milliseconds. In such an environment,
AIS and LDI should be treated the same and used solely for alarm
suppression. In more general MPLS environments the CC function may
be running at a much slower rate. In this environment, LDI enables
faster switch-over upon a failure occurring along the LSP.
2.4. MPLS-TP Locked Report 2.2. MPLS-TP Lock Report
The MPLS-TP Locked Report (LKR) message is generated when a server The MPLS-TP Lock Report (LKR) message is generated when a server
layer entity has been administratively locked to communicated that layer entity has been administratively locked to communicated that
condition to inform the client layer entities of that condition. condition to inform the client layer entities of that condition.
When an MPLS-TP LSP is administratively locked it is not available to When an MPLS-TP LSP is administratively locked it is not available to
carry client traffic. Its purpose is to suppress alarms in the carry client traffic. Its purpose is to suppress alarms in the
MPLS-TP layer network above the level at which the defect occurs and MPLS-TP layer network above the level at which the defect occurs and
to allow the clients to differentiate the lock condition from a to allow the clients to differentiate the lock condition from a
defect condition. defect condition.
The receipt of an LKR message MAY be treated as the equivalent of The receipt of an LKR message MAY be treated as the equivalent of
loss of continuity at the client layer. Like AIS it also is used to loss of continuity at the client layer. Like AIS it also is used to
suppress alarms. suppress alarms.
3. MPLS Fault Management Channel 3. MPLS Fault Management Channel
The MPLS Fault Management channel is identified by the ACH as defined The MPLS Fault Management channel is identified by the ACH as defined
in RFC 5586 [4] with the Channel Type set to the MPLS Fault in RFC 5586 [4] with the Channel Type set to the MPLS Fault
Management (FM) code point = 0xHH. [HH to be assigned by IANA from Management (FM) code point = 0xHH. [HH to be assigned by IANA from
the PW Associated Channel Type registry.] The FM Channel uses ACH the PW Associated Channel Type registry.] The FM Channel does not
TLVs and MUST include the ACH TLV header. The FM ACH Channel and ACH use ACH TLVs and MUST not include the ACH TLV header. The FM ACH
TLVs are shown below. Channel is shown below.
0 1 2 3 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 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 | 0xHH Fault Management Channel | |0 0 0 1|Version| Reserved | 0xHH Fault Management Channel |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ACH TLV Header |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ~
~ zero or more ACH TLVs ~
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ~ | ~
~ MPLS Fault Management Message ~ ~ MPLS Fault Management Message ~
~ | ~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: ACH Indication of the MPLS-TP Fault Management Channel Figure 1: ACH Indication of the MPLS-TP Fault Management Channel
The Fault Management Channel is 0xHH (to be assigned by IANA) The Fault Management Channel is 0xHH (to be assigned by IANA)
The ACH TLVs may include (but are not limited to) the IF_ID,
Global-ID, ICC, and Authentication TLVs.
4. MPLS Fault Management Message Format 4. MPLS Fault Management Message Format
The format of the Fault Management message is shown below. The format of the Fault Management message is shown below.
0 1 2 3 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 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 |Flgs |R| Msg Type | Refresh Timer | Total TLV Len | | Vers | Resvd | Msg Type | Flags | Refresh Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLVs | | Total TLV Len | ~
~ ~ +-+-+-+-+-+-+-+-+ TLVs ~
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: MPLS-TP OAM Message Format Figure 2: MPLS-TP OAM Message Format
Version Version
The Version Number is currently 1. The Version Number is currently 1.
Flags Reserved
One flag, the R-Flag is defined. The other flags in this field
MUST be set to zero on transmission and ignored on receipt.
R-flag
The R-flag is normally set to zero. A setting of one indicates This field MUST be set to zero on transmission and ignored on
the removal of a previously sent FM condition. receipt.
Message Type Message Type
The Message Type indicates the type of condition as listed in the The Message Type indicates the type of condition as listed in the
table below. table below.
Msg Type Description Msg Type Description
-------- ----------------------------- -------- -----------------------------
0x0 Reserved 0x0 Reserved
0x1 Alarm Indication Signal (AIS) 0x1 Alarm Indication Signal (AIS)
0x2 Link Down Indication (LDI) 0x2 Lock Report (LKR)
0x3 Locked Report (LKR)
Refresh Timer Refresh Timer
The maximum time between successive FM messages specified in The maximum time between successive FM messages specified in
seconds. The range is 1 to 65535. The value 0 is not permitted. seconds. The range is 1 to 65535. The value 0 is not permitted.
Total TLV Length Total TLV Length
The total TLV length is the total of all included TLVs. At this The total TLV length is the total of all included TLVs. At this
time no TLVs are defined. time no TLVs are defined.
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
L-flag
Link Down Indication. See section Section 2.1.1 for details on
setting this bit.
R-flag
The R-flag is normally set to zero. A setting of one indicates
the removal of a previously sent FM condition.
4.1. Fault Management Message TLVs
TLVs are used in fault OAM 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, Global-ID, and ICC.
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
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
This TLV carries the Interface Identifier 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
This TLV carries the Interface Identifier 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
4.1.3. International Carrier Code
This TLV carries the International Carrier Code. The Type is 0x3.
The length is 0x8. The value is an Octet string padded with nulls.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| International Carrier Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| International Carrier Code (Cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: International Carrier Code
5. Sending and Receiving Fault Management Messages 5. Sending and Receiving Fault Management Messages
5.1. Sending a Fault Management Message 5.1. Sending a Fault Management Message
Service disruptive conditions are indicated by sending FM messages. Service disruptive conditions are indicated by sending FM messages.
The message type is set to the value corresponding to the condition. The message type is set to the value corresponding to the condition.
The refresh timer is set to the maximum time between successive FM The refresh timer is set to the maximum time between successive FM
messages. This value MUST not be changed on successive FM messages. messages. This value MUST not be changed on successive FM messages.
If the optional clearing procedures are not used, then the default If the optional clearing procedures are not used, then the default
value is 1. Otherwise the default value is 20. value is 1. Otherwise the default value is 20.
The message is then prepended with an ACH TLV header. A Global-ID A Global-ID TLV or an ICC TLV MAY be included. The IF_ID TLV SHOULD
TLV or an ICC TLV MAY be included. The IF_ID TLV SHOULD be included. be included. If the R-Flag clearing procedures are to be used, the
If the R-Flag clearing procedures are to be used, the IF_ID TLV MUST IF_ID TLV MUST be included.
be included.
The message is then sent. The message MUST be refreshed twice at an The message is then sent. The message MUST be refreshed twice at an
interval of one second. Further refreshes are sent according to the interval of one second. Further refreshes are sent according to the
value of the refresh timer. Refreshing continues until the condition value of the refresh timer. Refreshing continues until the condition
is cleared. is cleared.
5.2. Clearing a FM Indication 5.2. Clearing a FM Indication
Ceasing to send FM messages will clear the indication after 3.5 times Ceasing to send FM messages will clear the indication after 3.5 times
the Refresh Timer. To clear an indication more quickly, the the Refresh Timer. To clear an indication more quickly, the
skipping to change at page 10, line 36 skipping to change at page 11, line 20
matching the message type and IF_ID exists. If it does, that matching the message type and IF_ID exists. If it does, that
condition is cleared. Otherwise the message is ignored. condition is cleared. Otherwise the message is ignored.
6. Security Considerations 6. Security Considerations
Spurious fault OAM messages form a vector for a denial of service Spurious fault OAM messages form a vector for a denial of service
attack. However, since these messages are carried in a control attack. However, since these messages are carried in a control
channel, one would have to gain access to a node providing the channel, one would have to gain access to a node providing the
service in order to effect such an attack. Since transport networks service in order to effect such an attack. Since transport networks
are usually operated as a walled garden, such threats are less are usually operated as a walled garden, such threats are less
likely. However, to ensure against such an attack the Authentication likely.
TLV MAY be included among the ACH TLVs.
7. IANA Considerations 7. IANA Considerations
7.1. 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)
7.2. MPLS Fault OAM Message Type 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 [6]) and "Private 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 251-255 are for Private Use, and MUST NOT be allocated.
Message Types defined in this document are:
Msg Type Description
-------- -----------------------------
0x0 Reserved
0x1 Alarm Indication Signal (AIS)
0x2 Lock Report (LKR)
7.3. 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 [6]), "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
in the range 192-248 are made via "Specification Required"; values in
the range 248-255 are for Private Use, and MUST NOT be allocated.
TLVs defined in this document are:
Value TLV Name
----- -------
0 Reserved
1 Interface Identifier TLV
2 Global Identifier
3 International Carrier Code
8. References 8. References
8.1. Normative References 8.1. Normative References
[1] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S. [1] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S.
Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, Ueno, "Requirements of an MPLS Transport Profile", RFC 5654,
September 2009. September 2009.
[2] Vigoureux, M. and D. Ward, "Requirements for OAM in MPLS [2] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Transport Networks", draft-ietf-mpls-tp-oam-requirements-06 Operations, Administration, and Maintenance (OAM) in MPLS
(work in progress), March 2010. Transport Networks", RFC 5860, May 2010.
[3] Bradner, S., "Key words for use in RFCs to Indicate Requirement [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[4] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic [4] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
Associated Channel", RFC 5586, June 2009. Associated Channel", RFC 5586, June 2009.
[5] Boutros, S., Bryant, S., Sivabalan, S., Swallow, G., Ward, D., [5] Bocci, M. and G. Swallow, "MPLS-TP Identifiers",
and V. Manral, "Definition of ACH TLV Structure", draft-ietf-mpls-tp-identifiers-01 (work in progress),
draft-ietf-mpls-tp-ach-tlv-02 (work in progress), March 2010. March 2010.
[6] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
8.2. Informative References 8.2. Informative References
Authors' Addresses Authors' Addresses
George Swallow (editor) George Swallow (editor)
Cisco Systems, Inc. Cisco Systems, Inc.
300 Beaver Brook Road 300 Beaver Brook Road
Boxborough, Massachusetts 01719 Boxborough, Massachusetts 01719
United States United States
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