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Internet Engineering Task Force (IETF) A. Takacs
Request for Comments: 7369 B. Gero
Category: Standards Track Ericsson
ISSN: 2070-1721 H. Long
Huawei
October 2014
GMPLS RSVP-TE Extensions for Ethernet
Operations, Administration, and Maintenance (OAM) Configuration
Abstract
The work related to GMPLS Ethernet Label Switching (GELS) extended
GMPLS RSVP-TE to support the establishment of Ethernet Label
Switching Paths (LSPs). IEEE Ethernet Connectivity Fault Management
(CFM) specifies an adjunct Operations, Administration, and
Maintenance (OAM) flow to check connectivity in Ethernet networks.
CFM can also be used with Ethernet LSPs for fault detection and
triggering recovery mechanisms. The ITU-T Y.1731 specification
builds on CFM and specifies additional OAM mechanisms, including
Performance Monitoring, for Ethernet networks. This document
specifies extensions of the GMPLS RSVP-TE protocol to support the
setup of the associated Ethernet OAM entities of Ethernet LSPs and
defines the Ethernet technology-specific TLVs based on the GMPLS OAM
Configuration Framework. This document supports, but does not
modify, the IEEE and ITU-T OAM mechanisms.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7369.
Takacs, et al. Standards Track [Page 1]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
Copyright Notice
Copyright (c) 2014 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Overview of Ethernet OAM Operation . . . . . . . . . . . . . 3
3. GMPLS RSVP-TE Extensions . . . . . . . . . . . . . . . . . . 5
3.1. Operation Overview . . . . . . . . . . . . . . . . . . . 5
3.2. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 7
3.3. Ethernet OAM Configuration Sub-TLV . . . . . . . . . . . 8
3.3.1. MD Name Sub-TLV . . . . . . . . . . . . . . . . . . . 9
3.3.2. Short MA Name Sub-TLV . . . . . . . . . . . . . . . . 10
3.3.3. MEP ID Sub-TLV . . . . . . . . . . . . . . . . . . . 11
3.3.4. Continuity Check (CC) Sub-TLV . . . . . . . . . . . . 12
3.4. Proactive Performance Monitoring . . . . . . . . . . . . 12
3.5. Summary of Ethernet OAM Configuration Errors . . . . . . 13
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
4.1. RSVP-TE OAM Configuration Registry . . . . . . . . . . . 14
4.2. Ethernet Sub-TLVs Sub-Registry . . . . . . . . . . . . . 15
4.3. RSVP Error Code . . . . . . . . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.1. Normative References . . . . . . . . . . . . . . . . . . 16
6.2. Informative References . . . . . . . . . . . . . . . . . 17
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 17
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
Takacs, et al. Standards Track [Page 2]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
1. Background
Provider Backbone Bridging - Traffic Engineering (PBB-TE)
[IEEE.802.1Q-2011] decouples the Ethernet data and control planes and
allows external control and management mechanisms to create
explicitly routed Ethernet connections. In addition, PBB-TE defines
mechanisms for protection switching of bidirectional Ethernet
connections. Ethernet Connectivity Fault Management (CFM) defines an
adjunct connectivity-monitoring OAM flow to check the liveliness of
Ethernet networks [IEEE.802.1Q-2011], including the monitoring of
specific explicitly routed Ethernet connections. The ITU-T
Recommendation Y.1731 [ITU-T.G.8013-2013] extended CFM and specified
additional OAM functionality.
In the IETF, the work related to GMPLS Ethernet Label Switching
(GELS) extended the GMPLS control plane to support the establishment
of explicitly routed Ethernet connections [RFC5828] [RFC6060]. We
refer to GMPLS-established Ethernet connections as "Ethernet LSPs".
GELS enables the application of MPLS-TE and GMPLS provisioning and
recovery features in Ethernet networks.
The use of GMPLS RSVP-TE to support the establishment and
configuration of OAM entities with LSP signaling is defined in a
technology-agnostic way in [RFC7260]. The purpose of this document
is to specify the additional technology-specific OAM entities to
support Ethernet connections.
1.1. 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 [RFC2119].
2. Overview of Ethernet OAM Operation
For the purposes of this document, we only discuss Ethernet OAM
aspects that are relevant for proactive connectivity monitoring of
Ethernet LSPs and assume that on-demand OAM functions will be
supported by management-plane operations.
PBB-TE defines point-to-point Ethernet Switched Paths (ESPs) as a
provisioned, traffic-engineered, unidirectional connectivity,
identified by the 3-tuple [ESP-MAC DA, ESP-MAC SA, ESP-VID], where
the ESP-MAC DA is the destination address of the ESP, the ESP-MAC SA
is the source address of the ESP, and the ESP-VID is a VLAN
identifier allocated for explicitly routed connections. To form a
bidirectional PBB-TE connection, two co-routed point-to-point ESPs
are combined. The combined ESPs must have the same ESP-MAC addresses
Takacs, et al. Standards Track [Page 3]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
but may have different ESP-VIDs. The formed co-routed bidirectional
path is a path where the forward and backward directions follow the
same route (links and nodes) across the network.
Note that although it would be possible to use GMPLS to set up a
single unidirectional ESP, the Ethernet OAM mechanisms are only fully
functional when bidirectional connections are established with co-
routed ESPs. Therefore, the scope of this document only covers
bidirectional point-to-point PBB-TE connections.
At both ends of the bidirectional point-to-point PBB-TE connection,
one Maintenance Entity Group End Point (MEP) is configured. The MEPs
monitoring a PBB-TE connection must be configured with the same
Maintenance Domain Level (MD Level) and Maintenance Association
Identifier (MAID). Each MEP has a unique identifier, the MEP ID.
Besides these identifiers, a MEP monitoring a PBB-TE connection must
be provisioned with the 3-tuples [ESP-MAC DA, ESP-MAC SA, ESP-VID] of
the two ESPs.
In the case of point-to-point VLAN connections, the connection may be
identified with a single VLAN or with two VLANs, one for each
direction. Therefore, instead of the 3-tuples of the PBB-TE ESPs,
MEPs must be provisioned with the proper VLAN identifiers.
MEPs exchange Connectivity Check Messages (CCMs) periodically with
fixed intervals. Eight distinct intervals are defined in
[IEEE.802.1Q-2011]:
+---+--------------------+----------------+
| # | CCM Interval (CCI) | 3-Bit Encoding |
+---+--------------------+----------------+
| 0 | Reserved | 000 |
| | | |
| 1 | 3 1/3 ms | 001 |
| | | |
| 2 | 10 ms | 010 |
| | | |
| 3 | 100 ms | 011 |
| | | |
| 4 | 1 s | 100 |
| | | |
| 5 | 10 s | 101 |
| | | |
| 6 | 1 min | 110 |
| | | |
| 7 | 10 min | 111 |
+---+--------------------+----------------+
Table 1: CCM Interval Encoding
Takacs, et al. Standards Track [Page 4]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
If three consecutive CCMs are lost, connectivity failure is declared.
The MEP detecting the failure will signal the defect to the remote
MEP in the subsequent CCMs it emits by setting the Remote Defect
Indicator (RDI) bit in the CCM. If a MEP receives a CCM with the RDI
bit set, it immediately declares failure. The detection of a failure
may trigger protection switching mechanisms or may be signaled to a
management system.
At each transit node, Maintenance Entity Group Intermediate Points
(MIPs) may be established to help failure localization, e.g., using
link trace and loopback functions. MIPs need to be provisioned with
a subset of the MEP identification parameters described above.
3. GMPLS RSVP-TE Extensions
3.1. Operation Overview
To simplify the configuration of connectivity monitoring, the
associated MEPs should be automatically established when an Ethernet
LSP is signaled. To monitor an Ethernet LSP, a set of parameters
must be provided to set up a Maintenance Association and related
MEPs. Optionally, MIPs may be created at the transit nodes of the
Ethernet LSP. The LSP Attribute Flags "OAM MEP entities desired" and
"OAM MIP entities desired", as described in [RFC7260], are used to
signal that the respective OAM entities must be established. An OAM
Configuration TLV, as described in [RFC7260], is added to the
LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES objects specifying that
Ethernet OAM is to be set up for the LSP. Information specific to
Ethernet OAM, as described below, is carried in the new Ethernet OAM
Configuration Sub-TLV (see Section 3.3) within the OAM Configuration
TLV.
o A unique MAID must be allocated for the PBB-TE connection, and
both MEPs must be configured with the same information. The MAID
consists of an optional Maintenance Domain Name (MD Name) and a
mandatory Short Maintenance Association Name (Short MA Name).
Various formatting rules for these names have been defined in
[IEEE.802.1Q-2011]. Since this information is also carried in all
CCMs, the combined length of the MD Name and Short MA Name is
limited to 44 bytes (see [IEEE.802.1Q-2011] for the details of the
message format). How these parameters are determined is out of
the scope of this document.
o Each MEP must be provisioned with a MEP ID. The MEP ID uniquely
identifies a given MEP within a Maintenance Association. That is,
the combination of MAID and MEP ID must uniquely identify a MEP.
How the value of the MEP ID is determined is out of the scope of
this document.
Takacs, et al. Standards Track [Page 5]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
o The Maintenance Domain Level (MD Level) allows hierarchical
separation of monitoring entities. [IEEE.802.1Q-2011] allows
differentiation of eight levels. How the value of the MD Level is
determined is out of the scope of this document. Note that
probably for all Ethernet LSPs, a single (default) MD Level will
be used within a network domain.
o The desired CCM Interval must be specified by the management
system based on service requirements or operator policy. The same
CCM Interval must be set in each of the MEPs monitoring a given
Ethernet LSP. How the value of the CCM Interval is determined is
out of the scope of this document.
o The desired forwarding priority to be set by MEPs for the CCM
frames may be specified. The same CCM priority must be set in
each of the MEPs monitoring a given Ethernet LSP. How CCM
priority is determined is out of the scope of this document. Note
that the highest priority should be used as the default CCM
priority.
o MEPs must be aware of their own reachability parameters and those
of the remote MEP. In the case of bidirectional point-to-point
PBB-TE connections, this requires that the 3-tuples [ESP-MAC A,
ESP-MAC B, ESP-VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are
configured in each MEP, where the ESP-MAC A is the same as the
local MEP's Media Access Control (MAC) address and ESP-MAC B is
the same as the remote MEP's MAC address. The GMPLS Ethernet
Label format, as defined in [RFC6060], consists of the ESP-MAC DA
and ESP-VID. Hence, the necessary reachability parameters for the
MEPs can be obtained from the Ethernet Labels (i.e., carried in
the downstream and upstream labels). In the case of point-to-
point VLAN connections, MEPs need to be provisioned with the VLAN
identifiers only, which can be derived similarly from the Ethernet
Labels.
Based on the procedures described in [RFC6060] for bidirectional PBB-
TE Ethernet LSP establishment, the Ethernet OAM configuration
procedures are as follows.
When the RSVP-TE signaling is initiated for the bidirectional
Ethernet LSP, the local node generates a Path message and:
o Allocates an upstream label formed by combining its MAC address
(ESP-MAC A) and locally selected VID (ESP-VID1), which will be
used to receive traffic;
Takacs, et al. Standards Track [Page 6]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
o MUST include the OAM Configuration TLV with OAM Type set to
Ethernet OAM in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES
objects;
o MUST include the OAM Function Flags Sub-TLV in the OAM
Configuration TLV and set the OAM function flags as needed;
o MUST include an Ethernet OAM Configuration Sub-TLV in the OAM
Configuration TLV that specifies the CCM Interval and MD Level;
o MAY add an MD Name Sub-TLV (optional) and MUST add a Short MA Name
Sub-TLV (required) to the Ethernet OAM Configuration Sub-TLV,
which will unambiguously identify a Maintenance Association for
this specific PBB-TE connection. Note that values for these
parameters may be derived from the GMPLS LSP identification
parameters; and
o MUST include a MEP ID Sub-TLV in the Ethernet OAM Configuration
Sub-TLV and select two distinct integer values to identify the
local and remote MEPs within the Maintenance Association created
for monitoring of the point-to-point PBB-TE connection.
Once the remote node receives the Path message, it can use the
UPSTREAM_LABEL to extract the reachability information of the
initiator. Then, it allocates a Label by selecting a local MAC
address (ESP-MAC B) and VID (ESP-VID2) that will be used to receive
traffic. These parameters determine the reachability information of
the local MEP. That is, the 3-tuples [ESP-MAC A, ESP-MAC B, ESP-
VID1] and [ESP-MAC B, ESP-MAC A, ESP-VID2] are derived from the
Ethernet Labels. In addition, the information received in the
Ethernet OAM Configuration TLV is used to configure the local MEP.
Once the Resv message successfully arrives to the initiator, this end
can extract the remote side's reachability information from the Label
object and therefore has all the information needed to properly
configure its local MEP.
3.2. OAM Configuration TLV
This TLV is specified in [RFC7260] and is used to select which OAM
technology/method should be used for the LSP. In this document, a
new OAM Type, Ethernet OAM, is defined. IANA has allocated OAM Type
1 for Ethernet OAM in the "RSVP-TE OAM Configuration Registry".
Takacs, et al. Standards Track [Page 7]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
RSVP-TE OAM Configuration Registry
OAM Type Description
------------ ------------------
1 Ethernet OAM
When the Ethernet OAM Type is requested, the receiving node should
look for the corresponding technology-specific Ethernet OAM
Configuration Sub-TLV.
3.3. Ethernet OAM Configuration Sub-TLV
The Ethernet OAM Configuration Sub-TLV (depicted below) is defined
for configuration parameters specific to Ethernet OAM. The Ethernet
OAM Configuration Sub-TLV, when used, MUST be carried in the OAM
Configuration TLV. This new sub-TLV accommodates Ethernet 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 32 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version |MD L.| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: Indicates a new type, the Ethernet OAM Configuration Sub-TLV.
IANA has assigned the value 32 from the "OAM Sub-TLVs" space in the
"RSVP-TE OAM Configuration Registry".
Length: Indicates the total length of the TLV including padding and
including the Type and Length fields.
Version: Identifies the CFM protocol version according to
[IEEE.802.1Q-2011]. If a node does not support a specific CFM
version, an error MUST be generated: "OAM Problem/Unsupported OAM
Version".
MD L. (MD Level): Indicates the desired MD Level. Possible values
are defined according to [IEEE.802.1Q-2011]. If a node does not
support a specific MD Level, an error MUST be generated: "OAM
Problem/Unsupported MD Level".
Takacs, et al. Standards Track [Page 8]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
3.3.1. MD Name Sub-TLV
The optional MD Name Sub-TLV is depicted below. It MAY be used for
MD naming.
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) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Format | Name Length | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ MD Name ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 1, MD Name Sub-TLV. IANA will maintain an Ethernet TLV Type
space in the "RSVP-TE OAM Configuration Registry" for the sub-TLV
types carried in the Ethernet OAM Configuration Sub-TLV.
Length: Indicates the total length of the TLV, including padding and
the Type and Length fields.
Format: According to [IEEE.802.1Q-2011].
Name Length: The length of the MD Name field in bytes. This is
necessary to allow non-4-byte padded MD Name lengths.
MD Name: Variable-length field, formatted according to the format
specified in the Format field.
If an undefined Format is specified, an error MUST be generated: "OAM
Problem/Unknown MD Name Format". Also, the combined length of MD
Name and Short MA Name MUST be less than or equal to 44 bytes. If
this is violated, an error MUST be generated: "OAM Problem/Name
Length Problem". Note that it is allowed to have no MD Name;
therefore, the MD Name Sub-TLV is optional. In this case, the MA
Name must uniquely identify a Maintenance Association.
Takacs, et al. Standards Track [Page 9]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
3.3.2. Short MA Name Sub-TLV
The Short MA Name Sub-TLV is depicted below. This sub-TLV MUST be
present in the Ethernet 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Format | Name Length | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Short MA Name ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 2, Short MA Name Sub-TLV. IANA will maintain an Ethernet TLV
Type space in the "RSVP-TE OAM Configuration Registry" for the sub-
TLV types carried in the Ethernet OAM Configuration Sub-TLV.
Length: Indicates the total length of the TLV, including padding and
the Type and Length fields.
Format: According to [IEEE.802.1Q-2011].
Name Length: The length of the Short MA Name field in bytes. This is
necessary to allow non-4-byte padded MA Name lengths.
Short MA Name: Variable-length field formatted according to the
format specified in the Format field.
If an undefined Format is specified, an error MUST be generated: "OAM
Problem/Unknown MA Name Format". Also, the combined length of MD
Name and Short MA Name MUST be less than or equal to 44 bytes. If
this is violated, an error MUST be generated: "OAM Problem/Name
Length Problem". Note that it is allowed to have no MD Name; in this
case, the MA Name MUST uniquely identify a Maintenance Association.
Takacs, et al. Standards Track [Page 10]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
3.3.3. MEP ID Sub-TLV
The MEP ID Sub-TLV is depicted below. This sub-TLV MUST be present
in the Ethernet 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (3) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local MEP ID |T|R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote MEP ID |T|R| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 3, MEP ID Sub-TLV. IANA will maintain an Ethernet TLV Type
space in the "RSVP-TE OAM Configuration Registry" for the sub-TLV
types carried in the Ethernet OAM Configuration Sub-TLV.
Length: Indicates the total length of the TLV, including padding and
the Type and Length fields.
Local MEP ID: A 16-bit integer value in the range 1-8191 of the MEP
ID on the initiator side.
Remote MEP ID: A 16-bit integer value in the range 1-8191 of the MEP
ID to be set for the MEP established at the receiving side. This
value is determined by the initiator node. This is possible since a
new MAID is assigned to each PBB-TE connection, and MEP IDs must be
only unique within the scope of the MAID.
Two flags are defined: Transmit (T) and Receive (R). When T is set,
the corresponding MEP MUST send OAM packets. When R is set, the
corresponding MEP MUST expect to receive OAM packets. These flags
are used to configure the role of MEPs.
Takacs, et al. Standards Track [Page 11]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
3.3.4. Continuity Check (CC) Sub-TLV
The Continuity Check (CC) Sub-TLV is depicted below. This sub-TLV
MUST be present in the Ethernet 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prio | CCM I | Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 4, Continuity Check (CC) Sub-TLV. IANA will maintain an
Ethernet TLV Type space in the "RSVP-TE OAM Configuration Registry"
for the sub-TLV types carried in the Ethernet OAM Configuration Sub-
TLV.
Length: Indicates the total length of the TLV, including padding and
the Type and Length fields.
Prio: Indicates the priority to be set for CCM frames. In Ethernet,
3 bits carried in VLAN TAGs identify priority information. Setting
the priority is optional. If the most significant bit is set to
zero, the subsequent 3 priority bits will be ignored, and priority
bits of the Ethernet CCM frame will be set based on default values
specified in the Ethernet nodes. If the most significant bit is set
to 1, the subsequent 3 bits will be used to set the priority bits of
the Ethernet CCM frame.
CCM I (CCM Interval): MUST be set according to the 3-bit encoding
[IEEE.802.1Q-2011] shown in Table 1. As a consequence, the most
significant bit will be set to 0. Four bits are allocated to support
the configuration of CCM Intervals that may be specified in the
future. If a node does not support the requested CCM Interval, an
error MUST be generated: "OAM Problem/Unsupported CC Interval".
3.4. Proactive Performance Monitoring
Ethernet OAM functions for Performance Monitoring (PM) allow
measurements of different performance parameters including Frame Loss
Ratio, Frame Delay, and Frame Delay Variation as defined in
[ITU-T.G.8013-2013]. Only a subset of PM functions are operated in a
proactive fashion to monitor the performance of the connection
continuously. Proactive PM supports Fault Management functions by
providing an indication of decreased service performance and
therefore may provide triggers to initiate recovery procedures.
Takacs, et al. Standards Track [Page 12]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
While on-demand PM functions are, for the purposes of this document,
always initiated by management commands, for proactive PM, it may be
desirable to utilize the control plane for configuration and
activation together with Fault Management functions such as the
Continuity Check.
[ITU-T.G.8013-2013] defines dual-ended Loss Measurement as proactive
OAM for Performance Monitoring and as a PM function applicable to
Fault Management. For dual-ended Loss Measurement, each MEP
piggybacks transmitted and received frame counters on CC messages to
support and synchronize bidirectional Loss Measurements at the MEPs.
Dual-ended Loss Measurement is supported by setting the Performance
Monitoring/Loss OAM Function Flag and the Continuity Check Flag in
the OAM Function Flags Sub-TLV [RFC7260] and configuring the
Continuity Check functionality by including the Ethernet OAM
Configuration Sub-TLV. No additional configuration is required for
this type of Loss Measurement.
3.5. Summary of Ethernet OAM Configuration Errors
In addition to the error values specified in [RFC7260], this document
defines the following values for the "OAM Problem" Error Code.
o If a node does not support a specific CFM version, an error MUST
be generated: "OAM Problem/Unsupported OAM Version".
o If a node does not support a specific MD Level, an error MUST be
generated: "OAM Problem/Unsupported MD Level".
o If an undefined MD name format is specified, an error MUST be
generated: "OAM Problem/Unknown MD Name Format".
o If an undefined MA name format is specified, an error MUST be
generated: "OAM Problem/Unknown MA Name Format".
o The combined length of MD Name and Short MA Name must be less than
or equal to 44 bytes. If this is violated, an error MUST be
generated: "OAM Problem/Name Length Problem".
o If a node does not support the requested CCM Interval, an error
MUST be generated: "OAM Problem/Unsupported CC Interval".
Takacs, et al. Standards Track [Page 13]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
4. IANA Considerations
4.1. RSVP-TE OAM Configuration Registry
IANA maintains the "RSVP-TE OAM Configuration Registry". IANA has
assigned an "OAM Type" from this registry as follows:
o "Ethernet OAM" has been allocated type 1 from the "OAM Types" sub-
registry of the "RSVP-TE OAM Configuration Registry".
o "Ethernet OAM Configuration Sub-TLV" has been allocated type 32
from the technology-specific range of the "OAM Sub-TLVs" sub-
registry of the "RSVP-TE OAM Configuration Registry".
RSVP-TE OAM Configuration Registry
OAM Types
OAM Type Number | Description | Reference
-------------------------------------------
1 | Ethernet OAM | [RFC7369]
OAM Sub-TLVs
Sub-TLV Type | Description | Ref.
-----------------------------------------------------------
32 |Ethernet OAM Configuration Sub-TLV| [RFC7369]
Takacs, et al. Standards Track [Page 14]
RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
4.2. Ethernet Sub-TLVs Sub-Registry
IANA will maintain an "Ethernet Sub-TLVs Sub-Registry" in the "RSVP-
TE OAM Configuration Registry" for the sub-TLV types carried in the
Ethernet OAM Configuration Sub-TLV. This document defines the
following types.
Ethernet Sub-TLVs Sub-Registry
Range | Registration Procedures
------------+--------------------------
0-65534 | IETF Review
65535 | Experimental
Sub-TLV Type | Description | Ref.
---------------------------------------------------------
0 | Reserved | [RFC7369]
1 | MD Name Sub-TLV | [RFC7369]
2 | Short MA Name Sub-TLV | [RFC7369]
3 | MEP ID Sub-TLV | [RFC7369]
4 | Continuity Check Sub-TLV | [RFC7369]
5-65534 | Unassigned | [RFC7369]
65535 | Reserved for Experimental Use | [RFC7369]
4.3. RSVP Error Code
IANA maintains an Error Code, "OAM Problem", in the "Error Codes and
Globally-Defined Error Value Sub-Codes" sub-registry of the "Resource
Reservation Protocol (RSVP) Parameters" registry. [RFC7260] defines
a set of Error Value sub-codes for the "OAM Problem" Error Code.
This document defines additional Error Value sub-codes for the "OAM
Problem" Error Code as summarized below.
Value | Description | Reference
-------+---------------------------+-----------
7 | Unsupported OAM Version | [RFC7369]
8 | Unsupported MD Level | [RFC7369]
9 | Unknown MD Name Format | [RFC7369]
10 | Unknown MA Name Format | [RFC7369]
11 | Name Length Problem | [RFC7369]
12 | Unsupported CC Interval | [RFC7369]
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RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
5. Security Considerations
This document does not introduce any additional security issues to
those discussed in [RFC7260] and [RFC6060].
The signaling of OAM-related parameters and the automatic
establishment of OAM entities based on RSVP-TE messages add a new
aspect to the security considerations discussed in [RFC3473]. In
particular, a network element could be overloaded if a remote
attacker targeted that element by sending frequent periodic messages
requesting liveliness monitoring of a high number of LSPs. Such an
attack can efficiently be prevented when mechanisms for message
integrity and node authentication are deployed. Since the OAM
configuration extensions rely on the hop-by-hop exchange of exiting
RSVP-TE messages, procedures specified for RSVP message security in
[RFC2747] can be used to mitigate possible attacks.
For a more comprehensive discussion of GMPLS security and attack
mitigation techniques, please see "Security Framework for MPLS and
GMPLS Networks" [RFC5920].
6. References
6.1. Normative References
[IEEE.802.1Q-2011]
IEEE, "IEEE Standard for Local and metropolitan area
networks--Media Access Control (MAC) Bridges and Virtual
Bridged Local Area Networks", IEEE Std 802.1Q, 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6060] Fedyk, D., Shah, H., Bitar, N., and A. Takacs,
"Generalized Multiprotocol Label Switching (GMPLS) Control
of Ethernet Provider Backbone Traffic Engineering (PBB-
TE)", RFC 6060, March 2011,
<http://www.rfc-editor.org/info/rfc6060>.
[RFC7260] Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE
Extensions for Operations, Administration, and Maintenance
(OAM) Configuration", RFC 7260, June 2014,
<http://www.rfc-editor.org/info/rfc7260>.
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RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
6.2. Informative References
[ITU-T.G.8013-2013]
International Telecommunications Union, "OAM functions and
mechanisms for Ethernet based networks", ITU-T
Recommendation G.8013/Y.1731, November 2011.
[RFC2747] Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic
Authentication", RFC 2747, January 2000,
<http://www.rfc-editor.org/info/rfc2747>.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003,
<http://www.rfc-editor.org/info/rfc3473>.
[RFC5828] Fedyk, D., Berger, L., and L. Andersson, "Generalized
Multiprotocol Label Switching (GMPLS) Ethernet Label
Switching Architecture and Framework", RFC 5828, March
2010, <http://www.rfc-editor.org/info/rfc5828>.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010,
<http://www.rfc-editor.org/info/rfc5920>.
Acknowledgements
The authors would like to thank Francesco Fondelli, Adrian Farrel,
Loa Andersson, Eric Gray, and Dimitri Papadimitriou for their useful
comments.
Contributors
Don Fedyk
EMail: don.fedyk@hp.com
Dinesh Mohan
EMail: dinmohan@hotmail.com
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RFC 7369 GMPLS-Based Ethernet OAM Configuration October 2014
Authors' Addresses
Attila Takacs
Ericsson
Konyves Kalman krt. 11.
Budapest 1097
Hungary
EMail: attila.takacs@ericsson.com
Balazs Peter Gero
Ericsson
Konyves Kalman krt. 11.
Budapest 1097
Hungary
EMail: balazs.peter.gero@ericsson.com
Hao Long
Huawei
China
EMail: lonho@huawei.com
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