MPLS Working Group E. Bellagamba, Ed.
Internet-Draft Ericsson
Intended status: Standards Track L. Andersson
Expires: August 25, 2013 Huawei
P. Skoldstrom, Ed.
Acreo AB
D. Ward
Cisco
J. Drake
Juniper
February 21, 2013
Configuration of Pro-Active Operations, Administration, and Maintenance
(OAM) Functions for MPLS-based Transport Networks using LSP Ping
draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf-06
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 LSP-Ping
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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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 August 25, 2013.
Copyright Notice
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Copyright (c) 2013 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. Theory of Operations . . . . . . . . . . . . . . . . . . . . . 4
2.1. MPLS OAM Configuration Operation Overview . . . . . . . . 4
2.1.1. Configuration of BFD sessions . . . . . . . . . . . . 5
2.1.2. Configuration of Performance Monitoring . . . . . . . 5
2.1.3. Configuration of Fault Management Signals . . . . . . 6
2.2. OAM Functions TLV . . . . . . . . . . . . . . . . . . . . 6
2.2.1. BFD Configuration sub-TLV . . . . . . . . . . . . . . 8
2.2.1.1. Local Discriminator sub-TLV . . . . . . . . . . . 9
2.2.1.2. Negotiation Timer Parameters sub-TLV . . . . . . . 10
2.2.1.3. BFD Authentication sub-TLV . . . . . . . . . . . . 11
2.2.2. MPLS OAM Source MEP-ID sub-TLV . . . . . . . . . . . . 12
2.2.3. Performance Monitoring sub-TLV . . . . . . . . . . . . 12
2.2.3.1. MPLS OAM PM Loss sub-TLV . . . . . . . . . . . . . 14
2.2.3.2. MPLS OAM PM Delay sub-TLV . . . . . . . . . . . . 15
2.2.4. MPLS OAM FMS sub-TLV . . . . . . . . . . . . . . . . . 16
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
4. Security Considerations . . . . . . . . . . . . . . . . . . . 18
5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.1. Normative References . . . . . . . . . . . . . . . . . . . 18
5.2. Informative References . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
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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 in LSP-Ping [RFC4379]. 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-TP OAM functions running between LERs.
Initialization and control of on-demand MPLS-TP 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.
Pro-active MPLS-TP OAM is performed by four different protocols, Bi-
directional 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 monitor 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
a particular LSP. It should be noted that here we are not
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configuring on-demand throughput estimates based on saturating the
connection as defined in [RFC6371]. Rather, we only enable the
estimation of the current throughput based on loss measurements.
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
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. Theory of Operations
2.1. MPLS OAM Configuration Operation Overview
The MPLS-TP OAM tool set are described in [RFC6669].
LSP Ping, or alternatively RSVP-TE [RSVP-TE-CONF], can be used to
simply enable the different OAM functions, by setting the
corresponding flags in the "OAM Functions TLV". For a more detailed
configuration one may include sub-TLVs for the different OAM
functions in order to specify various parameters in detail.
Typically intermediate nodes should not process or modify any of the
OAM configuration TLVs but simply forward them to the end-node.
There is one exception to this and that is if the "MPLS OAM FMS sub-
TLV" is present. This sub-TLV has to be examined even by
intermediate nodes. The sub-TLV MAY be present if a flag is set in
the "OAM Functions TLV".
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2.1.1. 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
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.
2.1.2. Configuration of Performance Monitoring
It is possible to configure Performance Monitoring functionalities
such as Loss, Delay, Delay variation (jitter), and Throughput as
described in [RFC6374].
When configuring Performance monitoring functionalities it is
possible to choose either the default configuration, by only setting
the respective flags in the "OAM functions TLV", or a customized
configuration. To customize the configuration one would set the
respective flags in the including the respective Loss and/or Delay
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sub-TLVs).
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.
2.1.3. Configuration of Fault Management Signals
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. When configuring Fault Monitoring Signals 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 "MPLS OAM FMS sub-TLV").
If an intermediate point is meant to originate fault management
signal messages this means that such an intermediate point is
associated to a server MEP through a co-located MPLS-TP client/server
adaptation function. Such a server MEP needs to be configured by its
own LSP-ping session (or, alternatively, via an NMS or RSVP-TE).
However, by setting the "Fault Management subscription" flag in the
"MPLS OAM FMS sub-TLV" a client LSP can indicate that it would like
an association to be created to the server MEP(s) on any intermediate
nodes.
2.2. OAM Functions TLV
The "OAM Functions TLV" depicted below is carried as a TLV of the LSP
Echo request/response 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OAM Func. Type (16) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|C|V|L|D|F| OAM Function Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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The "OAM Functions TLV" contains a number of flags indicating which
OAM functions should be activated as well as OAM function specific
sub-TLVs with configuration parameters for the particular function.
Type: indicates a new type, the "OAM Functions TLV" (IANA to define,
suggested value 16).
Length: the length of the OAM Function Flags field including the
total length of the sub-TLVs in octets.
OAM Function Flags: a bitmap numbered from left to right as shown in
the figure.
These flags are defined in this document:
OAM Function Flag bit# Description
--------------------- ---------------------------
0 (C) Continuity Check (CC)
1 (V) Connectivity Verification (CV)
2 (F) Fault Management Signals (FMS)
3 (L) Performance Monitoring/Loss (PM/Loss)
4 (D) Performance Monitoring/Delay (PM/Delay)
5 (T) Throughput Measurement
6-31 Reserved (set all to 0s)
Sub-TLVs corresponding to the different flags 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. The "MPLS OAM
Source MEP-ID sub-TLV" MUST also be included. 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.
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- "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.
2.2.1. 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 Functions 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 (1) (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, suggested value 1).
Length: indicates the length of the TLV including sub-TLVs but
excluding the Type and Length field, in octets.
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.
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-
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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 LSP Echo request 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 LSP Echo reply 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.
2.2.1.1. 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.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lcl. Discr. Type (1) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Discriminator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "Local Discriminator sub-TLV" (IANA
to define, suggested value 1).
Length: indicates the TLV length in octets, excluding the Type and
Length field. (4)
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.
2.2.1.2. 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nego. Timer 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, suggested value 2).
Length: indicates the length of the parameters in octets (12).
Acceptable Min. Asynchronous TX interval: in case of S (symmetric)
flag set in the "BFD Configuration sub-TLV", it expresses the desired
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 SHOULD reply with
an interval greater than the one proposed.
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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 the "Unsupported BFD TX Echo rate interval"
error MUST be generated. By default the value is set to 0.
2.2.1.3. 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) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "BFD Authentication sub-TLV" (IANA to
define).
Length: indicates the TLV total length in octets, exluding the Type
and Length fields. (4)
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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.
2.2.2. MPLS OAM Source MEP-ID sub-TLV
The "MPLS OAM Source MEP-ID sub-TLV" depicted below is carried as a
sub-TLV of the "OAM Functions TLV".
Note that support of ITU IDs is out-of-scope.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source MEP-ID Type (4) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Node ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tunnel ID | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM Source MEP-ID sub-TLV"
(IANA to define, suggested value 3).
Length: indicates the length of the TLV in octets, excluding the Type
and Length fields. (8)
Source Node ID: 32-bit node identifier as defined in [RFC6370].
Tunnel ID: a 16-bit unsigned integer unique to the node as defined in
[RFC6370].
LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
defined in [RFC6370].
2.2.3. 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.
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The "Performance Monitoring sub-TLV" provides the configuration
information mentioned in Section 7 of [RFC6374]. It includes support
for the configuration of quality thresholds and, as described in
[RFC6374], "the crossing of which will trigger warnings or alarms,
and result reporting and exception notification will be integrated
into the system-wide network management and reporting framework."
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
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 (2)(IANA)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|D|L|J|Y|K|C| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "Performance Monitoring sub-TLV"
(IANA to define, suggested value 2).
Length: indicates the TLV length in octets, exluding the Type and
Length fields.
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)
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- 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.
2.2.3.1. 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
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 (16).
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
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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 milliseconds) 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 SHOULD reply with a higher interval. By default it is set to
(100) as per [RFC6375].
Test Interval: test messages interval in milliseconds as described in
[RFC6374]. By default it is set to (10) as per [RFC6375].
Loss Threshold: the threshold value of measured lost packets per
measurement over which action(s) SHOULD be triggered.
2.2.3.2. MPLS OAM PM Delay sub-TLV
The "MPLS OAM PM Delay sub-TLV" depicted below is carried as a sub-
TLV of the "Performance Monitoring 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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 2).
Length: indicates the length of the parameters in octets (16).
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 milliseconds) 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 with a higher interval. By default it is set to (1000)
as per [RFC6375].
Test Interval: test messages interval (in milliseconds) as described
in [RFC6374]. By default it is set to (10) as per [RFC6375].
Delay Threshold: the threshold value of measured two-way delay (in
milliseconds) over which action(s) SHOULD be triggered.
2.2.4. 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". When both working and protection
paths are configured, both LSPs SHOULD be configured with identical
settings of the E flag, T flag, and the refresh timer.
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 (3) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E|S|T| Reserved (set to all 0s)| Refresh Timer | PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type, the "MPLS OAM FMS sub-TLV" (IANA to
define, suggested value 3).
Length: indicates the length of the parameters in octets (4).
FMS Signal Flags are used to enable the FMS signals at end point MEPs
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and the Server MEPs of the links over which the LSP is forwarded. In
this document only the S flag pertains to Server MEPs.
The following flags are defined:
- E: Enable Alarm Indication Signal (AIS) and Lock Report (LKR)
signalling as described in [RFC6427]. Default value is 1
(enabled).
- S: Indicate to a server MEP that its should transmit AIS and LKR
signals on the client LSP. Default value is 0 (disabled).
- T: Set timer value, enabled the configuration of a specific
timer value. Default value is 0 (disabled).
- Remaining bits: Reserved for future specification and set to 0.
Refresh Timer: indicates the refresh timer of fault indication
messages, in seconds. The value MUST be between 1 to 20 seconds as
specified for the Refresh Timer field in [RFC6427]. If the edge LSR
receiving the Path message can not support the value it SHOULD reply
with a higher timer value.
PHB: identifies the per-hop behavior of packets with fault management
information.
3. IANA Considerations
This document specifies the following new TLV types:
- "OAM Functions" type: 16;
sub-TLV types to be carried in the "OAM Functions TLV":
- "BFD Configuration" type: 1;
- "MPLS OAM Performance Monitoring" type: 2;
- "MPLS OAM FMS" type: 3;
- "MPLS OAM Source MEP-ID" type: 4.
sub-TLV types to be carried in the "BFD Configuration sub-TLV":
- "Local Discriminator" type: 1;
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- "Negotiation Timer Parameters" type: 2;
- "BFD Authentication" sub-TLV type: 3.
sub-TLV types to be carried in the "Performance monitoring sub-TLV":
- "MPLS OAM PM Loss" type: 1;
- "MPLS OAM PM Delay" type: 2;
This document specifies additional Return Codes to LSP Ping:
- "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 ".
4. 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.
5. References
5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
and S. Ueno, "Requirements of an MPLS Transport Profile",
RFC 5654, September 2009.
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[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,
"Bidirectional Forwarding Detection (BFD) for MPLS Label
Switched Paths (LSPs)", RFC 5884, June 2010.
[RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
Profile (MPLS-TP) Identifiers", RFC 6370, September 2011.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, September 2011.
[RFC6427] Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S.,
and D. Ward, "MPLS Fault Management Operations,
Administration, and Maintenance (OAM)", RFC 6427,
November 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.
5.2. Informative References
[RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", RFC 4379,
February 2006.
[RFC6371] Busi, I. and D. Allan, "Operations, Administration, and
Maintenance Framework for MPLS-Based Transport Networks",
RFC 6371, September 2011.
[RFC6375] Frost, D. and S. Bryant, "A Packet Loss and Delay
Measurement Profile for MPLS-Based Transport Networks",
RFC 6375, September 2011.
[RFC6669] Sprecher, N. and L. Fang, "An Overview of the Operations,
Administration, and Maintenance (OAM) Toolset for MPLS-
Based Transport Networks", RFC 6669, July 2012.
[RSVP-TE-CONF]
Bellagamba, E., Andersson, L., Ward, D., and P.
Skoldstrom, "Configuration of pro-active MPLS-TP
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Operations, Administration, and Maintenance (OAM)
Functions Using RSVP-TE", 2012,
<draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext>.
Authors' Addresses
Elisa Bellagamba (editor)
Ericsson
Torshamnsgatan 48
Kista, 164 40
Sweden
Email: elisa.bellagamba@ericsson.com
Loa Andersson
Huawei
Skanorvagen 3
Johanneshov, 121 52
Sweden
Phone:
Email: loa@mail01.huawei.com
Pontus Skoldstrom (editor)
Acreo AB
Electrum 236
Kista, 164 40
Sweden
Phone: +46 8 6327731
Email: pontus.skoldstrom@acreo.se
Dave Ward
Cisco
Phone:
Email: dward@cisco.com
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John Drake
Juniper
Phone:
Email: jdrake@juniper.net
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