CCAMP Working Group E. Bellagamba, Ed.
Internet-Draft L. Andersson, Ed.
Intended status: Standards Track Ericsson
Expires: October 15, 2012 P. Skoldstrom, Ed.
Acreo AB
D. Ward
Juniper
A. Takacs
Ericsson
April 13, 2012
Configuration of Pro-Active Operations, Administration, and Maintenance
(OAM) Functions for MPLS-based Transport Networks using RSVP-TE
draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext-08
Abstract
This specification describes the configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM) Functions for a
given LSP using a set of TLVs that are carried by the RSVP-TE
protocol.
This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network.
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
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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 October 15, 2012.
Copyright Notice
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Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Contributing Authors . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Overview of MPLS OAM for Transport Applications . . . . . . . 4
3. Theory of Operations . . . . . . . . . . . . . . . . . . . . . 5
3.1. MPLS OAM Configuration Operation Overview . . . . . . . . 5
3.1.1. Configuration of BFD sessions . . . . . . . . . . . . 5
3.1.2. Configuration of Performance Monitoring . . . . . . . 6
3.1.3. Configuration of Fault Management Signals . . . . . . 6
3.2. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 7
3.3. BFD Configuration sub-TLV . . . . . . . . . . . . . . . . 9
3.3.1. Local Discriminator sub-TLV . . . . . . . . . . . . . 11
3.3.2. Negotiation Timer Parameters sub-TLV . . . . . . . . . 11
3.3.3. BFD Authentication sub-TLV . . . . . . . . . . . . . . 12
3.4. Performance Monitoring sub-TLV . . . . . . . . . . . . . . 13
3.4.1. MPLS OAM PM Loss sub-TLV . . . . . . . . . . . . . . . 14
3.4.2. MPLS OAM PM Delay sub-TLV . . . . . . . . . . . . . . 15
3.5. MPLS OAM FMS sub-TLV . . . . . . . . . . . . . . . . . . . 16
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
5. BFD OAM configuration errors . . . . . . . . . . . . . . . . . 18
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
7. Security Considerations . . . . . . . . . . . . . . . . . . . 18
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.1. Normative References . . . . . . . . . . . . . . . . . . . 19
8.2. Informative References . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
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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 TLVs carried by RSVP-TE [RFC3209]. In particular it
specifies the mechanisms necessary to establish MPLS-TP OAM entities
at the maintenance points for monitoring and performing measurements
on an LSP, as well as defining information elements and procedures to
configure pro-active MPLS OAM functions running between LERs.
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.
The Transport Profile of MPLS must, by definition [RFC5654], be
capable of operating without a control plane. Therefore there are
several options for configuring MPLS-TP OAM, without a control plane
by either using an NMS or LSP Ping, or with a control plane using
signaling protocols RSVP-TE and/or T-LDP. Use of T-LDP for
configuration of MPLS-TP OAM is outside of scope of this document.
Pro-active MPLS OAM is performed by three different protocols,
Bidirectional Forwarding Detection (BFD) [RFC6428] for Continuity
Check/Connectivity Verification, the delay measurement protocol (DM)
[RFC6374] for delay and delay variation (jitter) measurements, and
the loss measurement protocol (LM) [RFC6374] for packet loss and
throughput measurements. Additionally there is a number of Fault
Management Signals that can be configured.
BFD is a protocol that provides low-overhead, fast 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 support point-to-multipoint connections.
The delay and loss measurements protocols [RFC6374] use a simple
query/response model for performing bidirectional measurements that
allows the originating node to measure packet loss and delay in both
directions. By timestamping and/or writing current packet counters
to the measurement packets at four times (Tx and Rx in both
directions) current delays and packet losses can be calculated. By
performing successive delay measurements the delay variation (jitter)
can be calculated. Current throughput can be calculated from the
packet loss measurements by dividing the number of packets sent/
received with the time it took to perform the measurement, given by
the timestamp in LM header. Combined with a packet generator the
throughput measurement can be used to measure the maximum capacity of
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a particular LSP.
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. [RFC5860] defines the
requirements for the OAM functionality of MPLS-TP.
This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network.
1.1. Contributing Authors
This document is the result of a large team of authors and
contributors. The following is a list of the co-authors:
Gregory Mirsky
John Drake
Benoit Tremblay
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].
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 [RFC5860].
[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.
[RFC6374] 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
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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 in a signal fail condition.
3. Theory of Operations
3.1. MPLS OAM Configuration Operation Overview
RSVP-TE, or alternatively LSP Ping [LSP-PING CONF], can be used to
simply enable the different OAM functions, by setting the
corresponding flags in the "OAM Functions TLV". Additionally one may
include sub-TLVs for the different OAM functions in order to specify
different parameters in detail.
The presence of OAM configuration TLVs at intermediate nodes is
justified because the mid-points need to forward the RSVP-TE message
to the end point. No TLV processing or modification or following OAM
actions need to be taken at the intermediate points.
3.1.1. Configuration of BFD sessions
For this specification, BFD MUST be run in either one of the two
modes:
- Asynchronous mode, where both sides should be in active mode
- Unidirectional mode
In the simplest scenario LSP Ping, or alternatively RSVP-TE [RSVP-TE
CONF], is used only to bootstrap a BFD session for an LSP, without
any timer negotiation.
Timer negotiation can be performed either in subsequent BFD control
messages (in this case the operation is similar to LSP Ping based
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bootstrapping described in [RFC5884]) or directly in the LSP ping
configuration messages.
When BFD Control packets are transported in the G-ACh they are not
protected by any end-to-end checksum, only lower-layers are providing
error detection/correction. A single bit error, e.g. a flipped bit
in the BFD State field could cause the receiving end to wrongly
conclude that the link is down and in turn trigger protection
switching. To prevent this from happening the "BFD Configuration
sub-TLV" has an Integrity flag that when set enables BFD
Authentication using Keyed SHA1 with an empty key (all 0s) [RFC5880].
This would make every BFD Control packet carry an SHA1 hash of itself
that can be used to detect errors.
If BFD Authentication using a pre-shared key / password is desired
(i.e. authentication and not only error detection) the "BFD
Authentication sub-TLV" MUST be included in the "BFD Configuration
sub-TLV". The "BFD Authentication sub-TLV" is used to specify which
authentication method that should be used and which pre-shared key /
password that should be used for this particular session. How the
key exchange is performed is out of scope of this document.
3.1.2. Configuration of Performance Monitoring
It is possible to configure Performance Monitoring functionalities
such as Loss, Delay and Throughput as described in [RFC6374].
When configuring Performance monitoring functionalities it can be
chosen either the default configuration (by only setting the
respective flags in the "OAM functions TLV") or a customized
configuration (by including the respective Loss and/or Delay sub-
TLVs).
3.1.3. Configuration of Fault Management Signals
Additional OAM functions may be configured by setting the appropriate
flags in the "OAM Functions TLV", these include Performance
Measurements (packet loss, throughput, delay, and delay variation)
and Fault Management Signal handling.
By setting the PM Loss flag in the "OAM Functions TLV" and including
the "MPLS OAM PM Loss sub-TLV" one can configure the measurement
interval and loss threshold values for triggering protection.
Delay measurements are configured by setting PM Delay flag in the
"OAM Functions TLV" and including the "MPLS OAM PM Loss sub-TLV" one
can configure the measurement interval and the delay threshold values
for triggering protection.
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To configure Fault Monitoring Signals and their refresh time the FMS
flag in the "OAM Functions TLV" MUST be set and the "MPLS OAM FMS
sub-TLV" included. If an intermediate point is meant to originate
fault management signal messages this mean that such intermediate
point is associated to a server MEP through a co-located MPLS-TP
client/server adaptation function and such server MEP needs to be
configured by its own RSVP-TE session (or, in alternative, NMS or LSP
ping).
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 LSP and it is
defined in [OAM-CONF-FWK]. The "OAM Configuration TLV" is carried in
the LSP_ATTRIBUTES object in Path and Resv messages.
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"
(also defined in [OAM-CONF-FWK]) and look for the corresponding
technology specific configuration TLVs.
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Additional corresponding sub-TLVs are as follows:
- "BFD Configuration sub-TLV", which MUST be included if the CC
and/or the CV 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. If the I flag is
set, the "BFD Authentication sub-TLV" may be included.
- "MPLS OAM PM Loss sub-TLV" within the "Performance Monitoring
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. Such sub-TLV MAY also be
included in case the Throughput function flag is set and there is
the need to specify measurement interval different from the
default ones. In fact the throughput measurement make use of the
same tool as the loss measurement, hence the same TLV is used.
- "MPLS OAM PM Delay sub-TLV" within the "Performance Monitoring
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.
Moreover, if the CV or CC flag is set, the CC flag MUST be set as
well. 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>
Note that support of ITU IDs is out-of-scope.
GMPLS signaling [RFC3473] 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
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- Tunnel Sender Address = src_node_id
- LSP ID = LSP_Num
"Tunnel ID" and "Tunnel Sender Address" are included in the "SESSION"
object [RFC3209], 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 [RFC3209] which is mandatory in Path
messages.
[Author's note: the same "Unique MEP-ID of source" will be likely
required for Performance monitoring purposes. This need to be agreed
with [RFC6374] authors.]
3.3. BFD Configuration sub-TLV
The "BFD Configuration sub-TLV" (depicted below) is defined for BFD
OAM specific configuration parameters. The "BFD Configuration sub-
TLV" is carried as a sub-TLV of the "OAM Configuration TLV".
This 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BFD Conf. Type (3) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Vers.| PHB |N|S|I|G|U|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "BFD Configuration sub-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".
PHB: Identifies the Per-Hop Behavior (PHB) to be used for periodic
continuity monitoring messages.
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BFD Negotiation (N): If set timer negotiation/re-negotiation via BFD
Control Messages is enabled, when cleared it is disabled.
Symmetric session (S): If set the BFD session MUST use symmetric
timing values.
Integrity (I): If set BFD Authentication MUST be enabled. If the
"BFD Configuration sub-TLV" does not include a "BFD Authentication
sub-TLV" the authentication MUST use Keyed SHA1 with an empty pre-
shared key (all 0s).
Encapsulation Capability (G): if set, it shows the capability of
encapsulating BFD messages into G-Ach channel. If both the G bit and
U bit are set, configuration gives precedence to the G bit.
Encapsulation Capability (U): if set, it shows the capability of
encapsulating BFD messages into UDP packets. If both the G bit and U
bit are set, configuration gives precedence to the G bit.
Bidirectional (B): if set, it configures BFD in the Bidirectional
mode. If it is not set it configures BFD in unidirectional mode. In
the second case, the source node does not expect any Discriminator
values back from the destination node.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
in the Path message:
- "Local Discriminator sub-TLV";
- "Negotiation Timer Parameters sub-TLV" if the N flag is cleared.
The "BFD Configuration sub-TLV" MUST include the following sub-TLVs
in the Resv message:
- "Local Discriminator sub-TLV;"
- "Negotiation Timer Parameters sub-TLV" if:
- the N and S flags are cleared, or if:
- the N flag is cleared and the S flag is set, and the
Negotiation Timer Parameters sub-TLV received by the egress
contains unsupported values. In this case an updated
Negotiation Timer Parameters sub-TLV, containing values
supported by the egress node, is returned to the ingress.
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3.3.1. Local Discriminator sub-TLV
The "Local Discriminator sub-TLV" is carried as a sub-TLV of the "BFD
Configuration sub-TLV" and 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lcl. Discr. Type (1) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Discriminator
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the Local Discriminator sub-TLV (1) (IANA
to define).
Length: indicates the TLV total length in octets. (8)
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 sub-TLV
The "Negotiation Timer Parameters sub-TLV" is carried as a sub-TLV of
the "BFD Configuration sub-TLV" and 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timer Neg. Type (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous TX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous RX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Required Echo TX Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "Negotiation Timer Parameters sub-
TLV" (IANA to define).
Length: indicates the TLV total length in octets. (16)
Acceptable Min. Asynchronous TX interval: in case of S (symmetric)
flag set in the "BFD Configuration sub-TLV", it expresses the desired
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time interval (in microseconds) at which the ingress LER intends to
both transmit and receive BFD periodic control packets. If the
receiving edge LSR can not support such value, it can reply with an
interval greater than the one proposed.
In case of S (symmetric) flag cleared in the "BFD Configuration sub-
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 sub-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 sub-
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
[RFC5880] 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".
3.3.3. BFD Authentication sub-TLV
The "BFD Authentication sub-TLV" is carried as a sub-TLV of the "BFD
Configuration sub-TLV" and 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BFD Auth. Type (3) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Auth Type | Auth Key ID | Reserved (0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Type: indicates a new type, the "BFD Authentication sub-TLV" (IANA to
define).
Length: indicates the TLV total length in octets. (8)
Auth Type: indicates which type of authentication to use. The same
values as are defined in section 4.1 of [RFC5880] are used.
Auth Key ID: indicates which authentication key or password
(depending on Auth Type) should be used. How the key exchange is
performed is out of scope of this document.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
3.4. Performance Monitoring sub-TLV
If the "OAM functions TLV" has either the L (Loss), D (Delay) or T
(Throughput) flag set, the "Performance Monitoring sub-TLV" MUST be
present.
In case the values need to be different than the default ones the
"Performance Monitoring sub-TLV", "MPLS OAM PM Loss sub-TLV" MAY
include the following sub-TLVs:
- "MPLS OAM PM Loss sub-TLV" if the L flag is set in the "OAM
functions TLV";
- "MPLS OAM PM Delay sub-TLV" if the D flag is set in the "OAM
functions TLV";
The "Performance Monitoring sub-TLV" depicted below is carried as a
sub-TLV of the "OAM Functions TLV".
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Perf Monitoring Type(4) (IANA)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|D|L|J|Y|K|C| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: indicates the TLV total length in octets.
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Configuration Flags, for the specific function description please
refer to [RFC6374]:
- D: Delay inferred/direct (0=INFERRED, 1=DIRECT)
- L: Loss inferred/direct (0=INFERRED, 1=DIRECT)
- J: Delay variation/jitter (1=ACTIVE, 0=NOT ACTIVE)
- Y: Dyadic (1=ACTIVE, 0=NOT ACTIVE)
- K: Loopback (1=ACTIVE, 0=NOT ACTIVE)
- C: Combined (1=ACTIVE, 0=NOT ACTIVE)
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
3.4.1. MPLS OAM PM Loss sub-TLV
The "MPLS OAM PM Loss sub-TLV" depicted below is carried as a sub-TLV
of the "Performance Monitoring sub-TLV".
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 (1) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OTF |T|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Test Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Loss Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM PM Loss sub-TLV" (IANA to
define, suggested value 1).
Length: indicates the length of the parameters in octets (20).
OTF: Origin Timestamp Format of the Origin Timestamp field described
in [RFC6374]. By default it is set to IEEE 1588 version 1.
Configuration Flags, please refer to [RFC6374] for further details:
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- T: Traffic-class-specific measurement indicator. Set to 1 when
the measurement operation is scoped to packets of a particular
traffic class (DSCP value), and 0 otherwise. When set to 1, the
DS field of the message indicates the measured traffic class. By
default it is set to 1.
- B: Octet (byte) count. When set to 1, indicates that the
Counter 1-4 fields represent octet counts. When set to 0,
indicates that the Counter 1-4 fields represent packet counts. By
default it is set to 0.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
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. By default it is set to
(TBD).
Test Interval: test messages interval as described in [RFC6374]. By
default it is set to (TBD).
Loss Threshold: the threshold value of lost packets over which
protections MUST be triggered. By default it is set to (TBD).
3.4.2. MPLS OAM PM Delay sub-TLV
The "MPLS OAM PM Delay sub-TLV" depicted below is carried as a sub-
TLV of the "OAM Functions TLV".
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 (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OTF |T|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Test Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Delay Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM PM Loss sub-TLV" (IANA to
define, suggested value 1).
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Length: indicates the length of the parameters in octets (20).
OTF: Origin Timestamp Format of the Origin Timestamp field described
in [RFC6374]. By default it is set to IEEE 1588 version 1.
Configuration Flags, please refer to [RFC6374] for further details:
- T: Traffic-class-specific measurement indicator. Set to 1 when
the measurement operation is scoped to packets of a particular
traffic class (DSCP value), and 0 otherwise. When set to 1, the
DS field of the message indicates the measured traffic class. By
default it is set to 1.
- B: Octet (byte) count. When set to 1, indicates that the
Counter 1-4 fields represent octet counts. When set to 0,
indicates that the Counter 1-4 fields represent packet counts. By
default it is set to 0.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
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. By default it is set to
(TBD).
Test Interval: test messages interval as described in [RFC6374]. By
default it is set to (TBD).
Delay Threshold: the threshold value of measured delay (in
microseconds) over which protections MUST be triggered. By default
it is set to (TBD).
3.5. MPLS OAM FMS sub-TLV
The "MPLS OAM FMS sub-TLV" depicted below is carried as a sub-TLV of
the "OAM Configuration sub-TLV".
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 OAM FMS Type (5) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|D|L|C| Reserved (set to all 0s) | PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Refresh Timer |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM FMS sub-TLV" (IANA to
define).
Length: indicates the TLV total length in octets. (12)
Signal Flags should not be processed at intermediate nodes as they
only have an end-point significance. They are used to enable the
following signals at end points:
- 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]
- Remaining bits: Reserved for future specification and set to 0.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
Configuration Flags:
- PHB: identifies the per-hop behavior of packets with fault
management information. It is significant only when C flag is
set.
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.
4. IANA Considerations
This document specifies the following new TLV types:
- "BFD Configuration" type: 3;
- "Performance Monitoring" type: 4;
- "MPLS OAM FMS" type: 5.
sub-TLV types to be carried in the "BFD Configuration sub-TLV":
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- "Local Discriminator" sub-TLV type: 1;
- "Negotiation Timer Parameters" sub-TLV type: 2.
- "BFD Authentication" sub-TLV type: 3.
sub-TLV types to be carried in the "BFD Configuration sub-TLV":
- "MPLS OAM PM Loss" type: 1;
- "MPLS OAM PM Delay" 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:
- "MPLS OAM Unsupported Functionality";
- "OAM Problem/Unsupported TX rate interval";
- "OAM Problem/Unsupported RX rate interval";
- "OAM Problem/Unsupported unsupported Authentication Type";
- "OAM Problem, mismatch of Authentication Key ID ".
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 were to request
high frequency liveliness monitoring of a large number of LSPs,
targeting a single network element.
Security aspects will be covered in more detailed in subsequent
versions of this document.
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8. References
8.1. Normative References
[MPLS-FMS]
Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S.,
and D. Ward, "MPLS Fault Management OAM", 2009,
<draft-ietf-mpls-tp-fault>.
[MPLS-TP-IDENTIF]
Bocci, M., Swallow, G., and E. Gray, "MPLS-TP
Identifiers", 2010, <draft-ietf-mpls-tp-identifiers>.
[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.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, 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.
[RFC5860] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Operations, Administration, and Maintenance (OAM) in MPLS
Transport Networks", RFC 5860, May 2010.
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, June 2010.
[RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
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"Bidirectional Forwarding Detection (BFD) for MPLS Label
Switched Paths (LSPs)", RFC 5884, June 2010.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, September 2011.
[RFC6375] Frost, D. and S. Bryant, "A Packet Loss and Delay
Measurement Profile for MPLS-Based Transport Networks",
RFC 6375, September 2011.
[RFC6428] Allan, D., Swallow Ed. , G., and J. Drake Ed. , "Proactive
Connectivity Verification, Continuity Check, and Remote
Defect Indication for the MPLS Transport Profile",
RFC 6428, November 2011.
8.2. Informative References
[BFD-CCCV]
Allan, D., Swallow, G., and J. Drake, "Proactive
Connectivity Verification, Continuity Check and Remote
Defect indication for MPLS Transport Profile", 2010,
<draft-ietf-mpls-tp-bfd-cc-cv-rdi>.
[BFD-Ping]
Bahadur, N., Aggarwal, R., Ward, D., Nadeau, T., Sprecher,
N., and Y. Weingarten, "LSP Ping and BFD encapsulation
over ACH", 2010,
<draft-ietf-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>.
[LSP-PING CONF]
Bellagamba, E., Andersson, L., Ward, D., and P.
Skoldstrom, "Configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM)
Functions Using LSP Ping", 2010,
<draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf>.
[MPLS-TP OAM Analysis]
Sprecher, N., Weingarten, Y., and E. Bellagamba, "MPLS-TP
OAM Analysis", 2011, <draft-ietf-mpls-tp-oam-analysis>.
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[MPLS-TP-OAM-FWK]
Bocci, M. and D. Allan, "Operations, Administration and
Maintenance Framework for MPLS-based Transport Networks",
2010, <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.
[RFC5921] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L.
Berger, "A Framework for MPLS in Transport Networks",
RFC 5921, July 2010.
Authors' Addresses
Elisa Bellagamba (editor)
Ericsson
Torshamnsgatan 48
Kista, 164 40
Sweden
Email: elisa.bellagamba@ericsson.com
Loa Andersson (editor)
Ericsson
Torshamnsgatan 48
Kista, 164 40
Sweden
Phone:
Email: loa.andersson@ericsson.com
Pontus Skoldstrom (editor)
Acreo AB
Electrum 236
Kista, 164 40
Sweden
Phone: +46 8 6327731
Email: pontus.skoldstrom@acreo.se
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Dave Ward
Juniper
Phone:
Email: dward@juniper.net
Attila Takacs
Ericsson
1. Laborc u.
Budapest,
HUNGARY
Phone:
Email: attila.takacs@ericsson.com
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