CCAMP Working Group E. Bellagamba, Ed.
Internet-Draft L. Andersson, Ed.
Intended status: Standards Track Ericsson
Expires: September 6, 2010 P. Skoldstrom, Ed.
Acreo AB
D. Ward
Juniper
March 5, 2010
Configuration of pro-active MPLS-TP Operations, Administration, and
Maintenance (OAM) Functions Using RSVP-TE or LSP Ping
draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext-01
Abstract
This specification describes the configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM) Functions for a
given LSP using a common set of TLVs that is carried on either
RSVP-TE or LSP Ping.
Status of this Memo
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Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Contributing Authors . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.3. Overview of BFD OAM operation . . . . . . . . . . . . . . 4
2. Overview of MPLS OAM for Transport Applications . . . . . . . 4
3. Theory of Operations . . . . . . . . . . . . . . . . . . . . . 5
3.1. MPLS OAM Configuration Operation Overview . . . . . . . . 5
3.2. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 6
3.3. BFD Configuration TLV . . . . . . . . . . . . . . . . . . 8
3.3.1. Local Discriminator sub-TLV . . . . . . . . . . . . . 10
3.3.2. Negotiation Timer Parameters . . . . . . . . . . . . . 10
3.4. MPLS OAM PM Loss TLV . . . . . . . . . . . . . . . . . . . 11
3.5. MPLS OAM PM Delay TLV . . . . . . . . . . . . . . . . . . 12
3.6. MPLS OAM FMS TLV . . . . . . . . . . . . . . . . . . . . . 13
3.7. MPLS OAM SOURCE MEP-ID TLV for LSP Ping . . . . . . . . . 14
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
5. BFD OAM configuration errors . . . . . . . . . . . . . . . . . 15
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Normative References . . . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . . 17
Appendix A. Additional Stuff . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
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1. Introduction
This document describes the configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM) Functions for a
given LSP using a common set of TLVs carried on either RSVP-TE
[RFC3209] or LSP Ping [BFD-Ping]. In particular it specifies the
mechanisms necessary to establish MPLS-TP OAM entities monitoring an
LSP and defines information elements and procedures to configure pro-
active MPLS OAM functions. Initialization and control of on-demand
MPLS OAM functions are expected to be carried out by directly
accessing network nodes via a management interface; hence
configuration and control of on-demand OAM functions are out-of-scope
for this document.
Because the Transport Profile of MPLS, by definition [RFC5654], must
be capable of operating without a control plane, there are two
options for in-band OAM: by using an NMS or by using LSP-Ping if a
control plane is not instantiated.
Pro-active MPLS OAM is based on the Bidirectional Forwarding
Detection (BFD) protocol [BFD]. Bidirectional Forwarding Detection
(BFD), as described in [BFD], defines a protocol that provides low-
overhead, short-duration detection of failures in the path between
two forwarding engines, including the interfaces, data link(s), and
to the extent possible the forwarding engines themselves. BFD can be
used to track the liveliness and detect data plane failures of
MPLS-TP point-to-point and might also be extended to p2mp
connections.
MPLS Transport Profile (MPLS-TP) describes a profile of MPLS that
enables operational models typical in transport networks, while
providing additional OAM, survivability and other maintenance
functions not currently supported by MPLS. [MPLS-TP-OAM-REQ] defines
the requirements for the OAM functionality of MPLS-TP.
BFD has been chosen to be the basis of pro-active MPLS-TP OAM
functions. MPLS-TP OAM extensions for transport applications, for
which this document specifies the configuration, are specified in
[BFD-CCCV], [MPLS-PM], and [MPLS-FMS].
1.1. Contributing Authors
The editors gratefully acknowledge the contributions of John Drake,
Attila Takacs and Benoit Tremblay.
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1.2. Requirements Language
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 [RFC2119].
1.3. Overview of BFD OAM operation
BFD is a simple hello protocol that in many respects is similar to
the detection components of well-known routing protocols. A pair of
systems transmits BFD packets periodically over each path between the
two systems, and if a system stops receiving BFD packets for long
enough, some component in that particular bidirectional path to the
neighboring system is assumed to have failed. Systems may also
negotiate to not send periodic BFD packets in order to reduce
overhead.
A path is only declared to be operational when two-way communication
has been established between systems, though this does not preclude
the use of unidirectional links to support bidirectional paths (co-
routed or bidirectional or associated bidirectional).
Each system estimates how quickly it can send and receive BFD packets
in order to come to an agreement with its neighbor about how rapidly
detection of failure will take place. These estimates can be
modified in real time in order to adapt to unusual situations. This
design also allows for fast systems on a shared medium with a slow
system to be able to more rapidly detect failures between the fast
systems while allowing the slow system to participate to the best of
its ability.
The ability of each system to control the BFD packet transmission
rate in both directions provides a mechanism for congestion control,
particularly when BFD is used across multiple network hops.
As recommended in [BFD-CCCV], the BFD tool needs to be extended for
the proactive CV functionality by the addition of an unique
identifier in order to meet the requirements. The document in [BFD-
CCCV] specifies the BFD extension and behavior to meet the
requirements for MPLS-TP proactive Continuity Check and Connectivity
Verification functionality and the RDI functionality as defined in
[MPLS-TP-OAM-REQ].
2. Overview of MPLS OAM for Transport Applications
[MPLS-TP-OAM-FWK] describes how MPLS OAM mechanisms are operated to
meet transport requirements outlined in [MPLS-TP-OAM-REQ].
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[BFD-CCCV] specifies two BFD operation modes: 1) "CC mode", which
uses periodic BFD message exchanges with symmetric timer settings,
supporting Continuity Check, 2) "CV/CC mode" which sends unique
maintenance entity identifiers in the periodic BFD messages
supporting Connectivity Verification as well as Continuity Check.
[MPLS-PM] specifies mechanisms for performance monitoring of LSPs, in
particular it specifies loss and delay measurement OAM functions.
[MPLS-FMS] specifies fault management signals with which a server LSP
can notify client LSPs about various fault conditions to suppress
alarms or to be used as triggers for actions in the client LSPs. The
following signals are defined: Alarm Indication Signal (AIS), Link
Down Indication (LDI) and Locked Report (LKR). To indicate client
faults associated with the attachment circuits Client Signal Failure
Indication (CSF) can be used. CSF is described in [MPLS-TP-OAM-FWK]
and in the context of this document is for further study.
[MPLS-TP-OAM-FWK] describes the mapping of fault conditions to
consequent actions. Some of these mappings may be configured by the
operator, depending on the application of the LSP. The following
defects are identified: Loss Of Continuity (LOC), Misconnectivity,
MEP Misconfiguration and Period Misconfiguration. Out of these
defect conditions, the following consequent actions may be
configurable: 1) whether or not the LOC defect should result in
blocking the outgoing data traffic; 2) whether or not the "Period
Misconfiguration defect" should result a signal fail condition.
3. Theory of Operations
3.1. MPLS OAM Configuration Operation Overview
RSVP-TE or LSP Ping can be used to simply establish (i.e., bootstrap)
a BFD session or it can selectively enable and configure all pro-
active MPLS OAM functions. For this specification, BFD MUST be run
in asynchronous mode and both sides should be in active mode.
In the simplest scenario RSVP-TE or LSP Ping is used only to
bootstrap the BFD session. In this case the initiating node includes
an 'OAM Configuration TLV' in the message it sends to the receiving
node at the other end of the LSP. The OAM Type in the 'OAM
Configuration TLV' is set to 'MPLS OAM', the CC OAM Function flag is
set, and a 'BFD Configuration sub-TLV' is included. The sub-TLV
carries a 'Local Discriminator sub-TLV' with the discriminator value
selected by the initiating node for the BFD session associated with
the LSP. The N flag in the 'BFD Configuration sub-TLV' MUST be set
to enable timer negotiation/re-negotiation via BFD Control Messages.
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The receiving node MUST use the Local Discriminator value it receives
to identify the remote end of the BFD session. The receiving node
must send a message to the initiating node that includes an 'OAM
Configuration TLV' containing the same values as it received, except
for the 'Local Discriminator sub-TLV', which contains the local
discriminator value selected by the receiving node for the BFD
session.
Timer negotiation is performed in subsequent BFD control messages.
This operation is similar to LSP Ping based bootstrapping described
in [BFD-MPLS].
If timer negotiation is to be done using the TLVs defined in this
document rather than with BFD Control Messages, the N flag MUST be
cleared and a 'Timer Negotiation Parameters sub-TLV' MUST be present
in the 'BFD Configuration sub-TLV'. In this case, there are two
configuration options, symmetric and asymmetric. If symmetric
configuration is used, the S flag in 'BFD Configuration sub-TLV' MUST
be set. If the flag is cleared, the configuration is completed
asymmetrically in the two directions. Section 3.3.2 includes a
detailed explanation of such configuration.
In the case of the "CV/CC mode" OAM [BFD-CCCV], the "CV" flag MUST be
set in addition to the CC flag in the "OAM Configuration TLV". The
information required to support this functionality is defined in
[MPLS-TP-IDENTIF]. If RSVP-TE is used, this information is found
respectively in the SESSION and SENDER_TEMPLATE object with no need
of further sub-TLV as described in section 3.2. In case of LSP Ping
configuration this information is supplied by an additional sub-TLV
as described in section 3.2.
Additional OAM functions can be requested by setting the PM/Loss and
PM/Delay OAM Function flags in the "OAM Configuration TLV". If these
flags are set, corresponding sub-TLVs may be included in the "OAM
Configuration TLV".
If Fault Management Signals [MPLS-FMS] are required, the Fault
Management Signals (FMS) OAM Function is set in the 'OAM
Configuration TLV'. If this flag is set, the corresponding sub-TLV
may be included in the 'OAM Configuration TLV'.
3.2. OAM Configuration TLV
The "OAM Configuration TLV" is depicted in the following figure. It
specifies the OAM functions that are to be used for the subject LSP
and it is defined in [OAM-CONF-FWK]. For RSVP-TE, the "OAM
Configuration TLV" is carried in the LSP_ATTRIBUTES object in Path
and Resv messages.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OAM Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates the "OAM Configuration TLV" (2) (IANA to assign).
OAM Type: one octet that specifies the technology specific OAM Type.
If the requested OAM Type is not supported, an error must be
generated: "OAM Problem/Unsupported OAM Type".
This document defines a new OAM Type: "MPLS OAM" (suggested value 2,
IANA to assign) from the "RSVP-TE OAM Configuration Registry". The
"MPLS OAM" type is set to request the establishment of OAM functions
for MPLS-TP LSPs. The specific OAM functions are specified in the
"Function Flags" sub-TLV as depicted in [OAM-CONF-FWK].
The receiving edge LSR when the MPLS-TP OAM Type is requested should
check which OAM Function Flags are set in the "Function Flags TLV"
and look for the corresponding technology specific configuration TLV.
Additional corresponding sub-TLVs are as follows:
- "BFD Configuration sub-TLV", which MUST be included if the CC
OAM Function flag is set. This sub-TLV MUST carry a "BFD Local
Discriminator sub-TLV" and a "Timer Negotiation Parameters sub-
TLV" if the N flag is cleared.
- "MPLS OAM PM Loss sub-TLV", which MAY be included if the PM/Loss
OAM Function flag is set. If the "MPLS OAM PM Loss sub-TLV" is
not included, default configuration values are used.
- "MPLS OAM PM Delay sub-TLV", which MAY be included if the PM/
Delay OAM Function flag is set. If the "MPLS OAM PM Delay sub-
TLV" is not included, default configuration values are used.
- "MPLS OAM FMS sub-TLV", which MAY be included if the FMS OAM
Function flag is set. If the "MPLS OAM FMS sub-TLV" is not
included, default configuration values are used.
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- "Unique MEP-ID of Source", which MUST be included in case the
configuration is done with LSP Ping and CV flag is set.
Moreover, if the CV flag is set, the CC flag MUST be set at the same
time. The format of an MPLS-TP CV/CC message is shown in [BFD-CCCV]
and it requires, together with the BFD control packet information,
the "Unique MEP-ID of source of BFD packet". [MPLS-TP-IDENTIF]
defines the composition of such identifier as:
<"Unique MEP-ID of source of BFD packet"> ::=
<src_node_id><src_tunnel_num><lsp_num>
GMPLS signaling [RFC 3473] uses a 5-tuple to uniquely identify an LSP
within an operator's network. This tuple is composed of a Tunnel
Endpoint Address, Tunnel_ID, Extended Tunnel ID, and Tunnel Sender
Address and (GMPLS) LSP_ID.
Hence, the following mapping is used without the need of redefining a
new TLV for MPLS-TP proactive CV purpose.
- Tunnel ID = src_tunnel_num
- Tunnel Sender Address = src_node_id
- LSP ID = LSP_Num
"Tunnel ID" and "Tunnel Sender Address" are included in the "SESSION"
object [RFC 3209], which is mandatory in both Path and Resv messages.
"LSP ID" will be the same on both directions and it is included in
the "SENDER_TEMPLATE" object [RFC 3209] which is mandatory in Path
messages.
In case the configuration is done via LSP Ping the "Unique MEP-ID of
Source" is needed to supply this information.
[Author's note: the same "Unique MEP-ID of source" will be likely
required for Performance monitoring purposes. However for the moment
in [MPLS-PM] it is stated: "The question of ACH TLV usage and the
manner of supporting metadata such as authentication keys and node
identifiers is deliberately omitted. These issues will be addressed
in a future version of the document."]
3.3. BFD Configuration TLV
The "BFD Configuration TLV" (depicted below) is defined for BFD OAM
specific configuration parameters. The "BFD Configuration TLV" is
carried as a sub-TLV of the "OAM Configuration TLV".
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This new TLV accommodates generic BFD OAM information and carries
sub-TLVs.
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 (3) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Vers.| PHB |N|S| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "BFD Configuration TLV" (IANA to
define).
Length: indicates the total length including sub-TLVs.
Version: identifies the BFD protocol version. If a node does not
support a specific BFD version an error must be generated: "OAM
Problem/Unsupported OAM Version &rdquo".
PHB: Identifies the Per-Hop Behavior (PHB) to be used for periodic
continuity monitoring messages.
BFD Negotiation (N): If set timer negotiation/re-negotiation via BFD
Control Messages is enabled, when cleared it is disabled.
The "BFD Configuration TLV" MUST include the following sub-TLVs in
the Path message:
- "Local Discriminator sub-TLV";
- "Negotiation Timer Parameters sub-TLV" if N flag is cleared.
The "BFD Configuration TLV" MUST include the following sub-TLVs in
the Resv message:
- "Local Discriminator sub-TLV;"
- "Negotiation Timer Parameters sub-TLV" if:
- N flag and S are cleared
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- N flag is cleared and S flag is set and a timing value higher
than the one received needs to be used
3.3.1. Local Discriminator sub-TLV
The "Local Discriminator sub-TLV" is carried as a sub-TLV of the BFD
Configuration sub-TLV. It is depicted 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (1) (IANA) | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Discriminator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the Local Discriminator sub TLV (1) (IANA
to define).
Length: indicates the TLV total length in octets.
Local Discriminator: A unique, nonzero discriminator value generated
by the transmitting system and referring to itself, used to
demultiplex multiple BFD sessions between the same pair of systems.
3.3.2. Negotiation Timer Parameters
The "Negotiation Timer Parameters sub-TLV" is depicted 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Req. TX int. Type (2) (IANA) | Length = 20 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous TX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous RX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Required Echo TX Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Detect. Mult.| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "Negotiation Timer Parameters sub-
TLV" (IANA to define).
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Length: indicates the TLV total length in octets.
Acceptable Min. Asynchronous TX interval: in case of S (symmetric)
flag set in the "BFD Configuration" TLV, it expresses the desired
time interval (in microseconds) at which the LER initiating the
signaling intends to both transmit and receive BFD periodic control
packets. If the receiving edge LSR can not support such value, it is
allowed to reply back with an interval greater than the one proposed.
In case of S (symmetric) flag cleared in the "BFD Configuration TLV",
this field expresses the desired time interval (in microseconds) at
which a edge LSR intends to transmit BFD periodic control packets in
its transmitting direction.
Acceptable Min. Asynchronous RX interval: in case of S (symmetric)
flag set in the "BFD Configuration TLV", this field MUST be equal to
"Acceptable Min. Asynchronous TX interval" and has no additional
meaning respect to the one described for "Acceptable Min.
Asynchronous TX interval".
In case of S (symmetric) flag cleared in the "BFD Configuration TLV",
it expresses the minimum time interval (in microseconds) at which
edge LSRs can receive BFD periodic control packets. In case this
value is greater than the "Acceptable Min. Asynchronous TX interval"
received from the other edge LSR, such edge LSR MUST adopt the
interval expressed in this "Acceptable Min. Asynchronous RX
interval".
Required Echo TX Interval: the minimum interval, in microseconds,
between received BFD Echo packets that this system is capable of
supporting, less any jitter applied by the sender as described in
[BFD] sect. 6.8.9. This value is also an indication for the
receiving system of the minimum interval between transmitted BFD Echo
packets. If this value is zero, the transmitting system does not
support the receipt of BFD Echo packets. If the receiving system can
not support this value an error MUST be generated "Unsupported BFD TX
rate interval".
Detection time multiplier: The negotiated transmit interval,
multiplied by this value, provides the Detection Time for the
receiving system in Asynchronous mode.
3.4. MPLS OAM PM Loss TLV
The "MPLS OAM PM Loss TLV" depicted below is carried as a sub-TLV of
the "OAM Configuration TLV".
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PM Loss Type (3) (IANA) | Length = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Vers.|E|C| | Reserved | PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Loss Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "PM Loss" (IANA to define).
Length: indicates the TLV total length in octets.
Version: indicates the Loss measurement protocol version.
Configuration Flags:
- E: exclude from the Loss Measurement all G-ACh messages
- C: require the use of a counter in the "Querier Context" field
described in [MPLS-PM]
- Remaining bits: Reserved for future specification and set to 0.
PHB: identifies the per-hop behavior of packets with loss
information.
Measurement Interval: the time interval (in microseconds) at which
Loss Measurement query messages MUST be sent on both directions. If
the edge LSR receiving the Path message can not support such value,
it can reply back with a higher interval.
Loss Threshold: the threshold value of lost packets over which
protections MUST be triggered.
3.5. MPLS OAM PM Delay TLV
The "MPLS OAM PM Delay TLV" depicted below is carried as a sub-TLV of
the "OAM Configuration TLV".
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PM Delay Type (4) (IANA) | Length = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Vers.| Flags | Reserved | PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Delay Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "PM Delay" (IANA to define).
Length: indicates the TLV total length in octets.
Version: indicates the Delay measurement protocol version.
Configuration Flags:
- E: exclude from the Loss Measurement all G-ACh messages
- C: require the use of a counter in the "Querier Context" field
described in [MPLS-PM]
- Remaining bits: Reserved for future specification and set to 0.
PHB: - identifies the per-hop behavior of packets with delay
information.
Measurement Interval: the time interval (in microseconds) at which
Delay Measurement query messages MUST be sent on both directions. If
the edge LSR receiving the Path message can not support such value,
it can reply back with a higher interval.
Delay Threshold: the threshold value of lost packets over which
protections MUST be triggered.
[Author's note: TBD if we want to include the timestamp format
negotiation as in [MPLS-PM] 4.2.5.]
3.6. MPLS OAM FMS TLV
The "MPLS OAM FMS TLV" depicted below is carried as a sub-TLV of the
"OAM Configuration TLV".
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (5) (IANA) | Length (12) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|D|L|C| Reserved | |E| PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Refresh Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "PM Delay" (IANA to define).
Length: indicates the TLV total length in octets.
Signal Flags: are used to enable the following signals:
- A: Alarm Indication Signal (AIS) as described in [MPLS-FMS]
- D: Link Down Indication (LDI) as described in [MPLS-FMS]
- L: Locked Report (LKR) as described in [MPLS-FMS]
- C: Client Signal Failure (CSF) as described in [MPLS-CSF]
Configuration Flags:
- E: used to enable/disable explicitly clearing faults
- PHB: identifies the per-hop behavior of packets with fault
management information
Refresh Timer: indicates the refresh timer (in microseconds) of fault
indication messages. If the edge LSR receiving the Path message can
not support such value, it can reply back with a higher interval.
3.7. MPLS OAM SOURCE MEP-ID TLV for LSP Ping
The "MPLS OAM SOURCE MEP-ID TLV for LSP Ping" depicted below is
carried as a sub-TLV of the "OAM Configuration TLV" in case LSP Ping
is used.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (6) (IANA) | Length = 12 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SRC NODE ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TUNNEL ID | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM SOURCE MEP-ID" (IANA to
define).
Length: indicates the TLV total length in octets.
SRC NODE ID: 32-bit node identifier as defined in [MPLS-TP-IDENTIF].
TUNNEL ID: a 16-bit unsigned integer unique to the node as defined in
[MPLS-TP-IDENTIF].
LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
defined in [MPLS-TP-IDENTIF].
4. IANA Considerations
This document specifies the following new TLV types:
- "BFD Configuration" type: 2;
- "MPLS OAM PM Loss" type: 3;
- "MPLS OAM PM Delay" type: 4;
- "MPLS OAM PM FMS" type: 5.
sub-TLV types to be carried in the "BFD Configuration sub-TLV":
- "Local Discriminator" sub-TLV type: 1;
- "Negotiation Timer Parameters" sub-TLV type: 2.
5. BFD OAM configuration errors
In addition to error values specified in [OAM-CONF-FWK] and [ETH-OAM]
this document defines the following values for the "OAM Problem"
Error Code:
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- "MPLS OAM Unsupported Functionality";
- "OAM Problem/Unsupported TX rate interval".
6. Acknowledgements
The authors would like to thank David Allan, Lou Berger, Annamaria
Fulignoli, Eric Gray, Andras Kern, David Jocha and David Sinicrope
for their useful comments.
7. Security Considerations
The signaling of OAM related parameters and the automatic
establishment of OAM entities introduces additional security
considerations to those discussed in [RFC3473]. In particular, a
network element could be overloaded, if an attacker would request
liveliness monitoring, with frequent periodic messages, for a high
number of LSPs, targeting a single network element.
Security aspects will be covered in more detailed in subsequent
versions of this document.
8. References
8.1. Normative References
[BFD] Katz, D. and D. Ward, "Bidirectional Forwarding
Detection", 2009, <draft-ietf-bfd-base>.
[MPLS-CSF]
He, J. and H. Li, "Indication of Client Failure in
MPLS-TP", 2009, <draft-he-mpls-tp-csf>.
[MPLS-FMS]
Swallow, G., Fulignoli, A., and M. Vigoureux, "MPLS Fault
Management OAM", 2009, <draft-sfv-mpls-tp-fault>.
[MPLS-PM] Bryant, S. and D. Frost, "Packet Loss and Delay
Measurement for the MPLS Transport Profile", 2009,
<draft-frost-mpls-tp-loss-delay>.
[MPLS-TP-IDENTIF]
Bocci, M. and G. Swallow, "MPLS-TP Identifiers", 2009,
<draft-swallow-mpls-tp-identifiers>.
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[MPLS-TP-OAM-REQ]
Vigoureux, M., Ward, D., and M. Betts, "Requirements for
OAM in MPLS Transport Networks", 2009,
<draft-ietf-mpls-tp-oam-requirements>.
[OAM-CONF-FWK]
Takacs, A., Fedyk, D., and J. van He, "OAM Configuration
Framework for GMPLS RSVP-TE", 2009,
<draft-ietf-ccamp-oam-configuration-fwk>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[RFC5586] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
Associated Channel", RFC 5586, June 2009.
[RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
and S. Ueno, "Requirements of an MPLS Transport Profile",
RFC 5654, September 2009.
8.2. Informative References
[BFD-CCCV]
Fulignoli, A., Boutros, S., and M. Vigoreux, "MPLS-TP BFD
for Proactive CC-CV and RDI", 2009,
<draft-asm-mpls-tp-bfd-cc-cv>.
[BFD-Ping]
Bahadur, N., Aggarwal, R., Ward, D., Nadeau, T., Sprecher,
N., and Y. Weingarten, "LSP-Ping and BFD encapsulation
over ACH", 2009,
<draft-nitinb-mpls-tp-lsp-ping-bfd-procedures-02>.
[ETH-OAM] Takacs, A., Gero, B., Fedyk, D., Mohan, D., and D. Long,
"GMPLS RSVP-TE Extensions for Ethernet OAM", 2009,
<draft-ietf-ccamp-rsvp-te-eth-oam-ext>.
[LSP Ping]
Kompella, K. and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", 2006, <RFC
3479>.
[MPLS-TP OAM Analysis]
Sprecher, N., Nadeau, T., van Helvoort, H., and
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Weingarten, "MPLS-TP OAM Analysis", 2006,
<draft-sprecher-mpls-tp-oam-analysis>.
[MPLS-TP-FWK]
Bocci, M., Bryant, S., Frost, D., and L. Levrau, "OAM
Configuration Framework for GMPLS RSVP-TE", 2009,
<draft-ietf-mpls-tp-framework>.
[MPLS-TP-OAM-FWK]
Busi, I. and B. Niven-Jenkins, "MPLS-TP OAM Framework and
Overview", 2009, <draft-ietf-mpls-tp-oam-framework>.
[RFC4447] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G.
Heron, "Pseudowire Setup and Maintenance Using the Label
Distribution Protocol (LDP)", RFC 4447, April 2006.
Appendix A. Additional Stuff
This becomes an Appendix.
Authors' Addresses
Elisa Bellagamba (editor)
Ericsson
Farogatan 6
Kista, 164 40
Sweden
Phone: +46 761440785
Email: elisa.bellagamba@ericsson.com
Loa Andersson (editor)
Ericsson
Farogatan 6
Kista, 164 40
Sweden
Phone:
Email: loa.andersson@ericsson.com
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Pontus Skoldstrom (editor)
Acreo AB
Electrum 236
Kista, 164 40
Sweden
Phone: +46 8 6327731
Email: pontus.skoldstrom@acreo.se
Dave Ward
Juniper
Phone:
Email: dward@juniper.net
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