draft-ietf-mpls-tp-data-plane-00.txt   draft-ietf-mpls-tp-data-plane-01.txt 
MPLS D. Frost, Ed. MPLS D. Frost, Ed.
Internet-Draft S. Bryant, Ed. Internet-Draft S. Bryant, Ed.
Intended status: Standards Track Cisco Systems Intended status: Standards Track Cisco Systems
Expires: August 28, 2010 M. Bocci, Ed. Expires: September 13, 2010 M. Bocci, Ed.
Alcatel-Lucent Alcatel-Lucent
February 24, 2010 March 12, 2010
MPLS Transport Profile Data Plane Architecture MPLS Transport Profile Data Plane Architecture
draft-ietf-mpls-tp-data-plane-00 draft-ietf-mpls-tp-data-plane-01
Abstract Abstract
The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP) The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP)
is the set of MPLS protocol functions applicable to the construction is the set of MPLS protocol functions applicable to the construction
and operation of packet-switched transport networks. This document and operation of packet-switched transport networks. This document
specifies the subset of these functions that comprises the MPLS-TP specifies the subset of these functions that comprises the MPLS-TP
data plane: the architectural layer concerned with the encapsulation data plane: the architectural layer concerned with the encapsulation
and forwarding of packets within an MPLS-TP network. and forwarding of packets within an MPLS-TP network.
skipping to change at page 2, line 9 skipping to change at page 2, line 9
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on August 28, 2010. This Internet-Draft will expire on September 13, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 12 skipping to change at page 3, line 12
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the BSD License. described in the BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. MPLS-TP Packet Encapsulation and Forwarding . . . . . . . . . 5 2. MPLS-TP Packet Encapsulation and Forwarding . . . . . . . . . 5
3. MPLS-TP Transport Entities . . . . . . . . . . . . . . . . . . 5 3. MPLS-TP Transport Entities . . . . . . . . . . . . . . . . . . 5
3.1. Label Switched Paths . . . . . . . . . . . . . . . . . . . 5 3.1. Label Switched Paths . . . . . . . . . . . . . . . . . . . 6
3.1.1. LSP Packet Encapsulation and Forwarding . . . . . . . 5 3.1.1. LSP Packet Encapsulation and Forwarding . . . . . . . 6
3.1.2. LSP Payloads . . . . . . . . . . . . . . . . . . . . . 6 3.1.2. LSP Payloads . . . . . . . . . . . . . . . . . . . . . 6
3.1.3. LSP Types . . . . . . . . . . . . . . . . . . . . . . 6 3.1.3. LSP Types . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Sections . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2. Sections . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3. Pseudowires . . . . . . . . . . . . . . . . . . . . . . . 8 3.3. Pseudowires . . . . . . . . . . . . . . . . . . . . . . . 9
4. MPLS-TP Generic Associated Channel . . . . . . . . . . . . . . 8 4. MPLS-TP Generic Associated Channel . . . . . . . . . . . . . . 9
5. Media-Specific Considerations . . . . . . . . . . . . . . . . 8 5. Server Layer Considerations . . . . . . . . . . . . . . . . . 10
5.1. Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.1. Ethernet Media . . . . . . . . . . . . . . . . . . . . . . 10
5.1.1. Destination MAC Address Determination . . . . . . . . 8 5.1.1. Point-to-Point Links . . . . . . . . . . . . . . . . . 10
5.2. Other Media . . . . . . . . . . . . . . . . . . . . . . . 9 5.1.2. Multipoint Links . . . . . . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . . 10 8.1. Normative References . . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
The MPLS Transport Profile (MPLS-TP) [I-D.ietf-mpls-tp-framework] is The MPLS Transport Profile (MPLS-TP) [I-D.ietf-mpls-tp-framework] is
the set of protocol functions that meet the requirements [RFC5654] the set of protocol functions that meet the requirements [RFC5654]
for the application of MPLS to the construction and operation of for the application of MPLS to the construction and operation of
packet-switched transport networks. Packet transport networks are packet-switched transport networks. Packet transport networks are
defined and described in [I-D.ietf-mpls-tp-framework]. defined and described in [I-D.ietf-mpls-tp-framework].
This document specifies the subset of protocol functions that This document specifies the subset of protocol functions that
skipping to change at page 4, line 29 skipping to change at page 4, line 29
(IETF) / International Telecommunication Union Telecommunication (IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network. capabilities and functionalities of a packet transport network.
1.1. Scope 1.1. Scope
This document has the following purposes: This document has the following purposes:
o To identify the data-plane functions within the MPLS Transport o To identify the data-plane functions within the MPLS Transport
Profile Profile;
o To indicate which of these data-plane functions an MPLS-TP o To indicate which of these data-plane functions an MPLS-TP
implementation is required to support implementation is required to support.
Note that the MPLS-TP functions discussed in this document are Note that the MPLS-TP functions discussed in this document are
considered OPTIONAL unless stated otherwise. considered OPTIONAL unless stated otherwise.
1.2. Terminology 1.2. Terminology
Term Definition Term Definition
------- ------------------------------------------ ------- ------------------------------------------
G-ACh Generic Associated Channel G-ACh Generic Associated Channel
GAL G-ACh Label GAL G-ACh Label
LER Label Edge Router
LSP Label Switched Path LSP Label Switched Path
LSR Label Switching Router LSR Label Switching Router
MAC Media Access Control MAC Media Access Control
MPLS-TP MPLS Transport Profile MPLS-TP MPLS Transport Profile
OAM Operations, Administration and Maintenance OAM Operations, Administration and Maintenance
PW Pseudowire PW Pseudowire
QoS Quality of Service QoS Quality of Service
TTL Time To Live
Additional definitions and terminology can be found in Additional definitions and terminology can be found in
[I-D.ietf-mpls-tp-framework] and [RFC5654]. [I-D.ietf-mpls-tp-framework] and [RFC5654].
2. MPLS-TP Packet Encapsulation and Forwarding 2. MPLS-TP Packet Encapsulation and Forwarding
This document defines the encapsulation and forwarding functions This document defines the encapsulation and forwarding functions
applicable to packets traversing an MPLS-TP Label Switched Path applicable to packets traversing an MPLS-TP Label Switched Path
(LSP), Pseudowire (PW), or Section (see Section 3 for the definitions (LSP), Pseudowire (PW), or Section (see Section 3 for the definitions
of these transport entities). Encapsulation and forwarding functions of these transport entities). Encapsulation and forwarding functions
for packets outside an MPLS-TP LSP, PW, or Section, and mechanisms for packets outside an MPLS-TP LSP, PW, or Section, and mechanisms
for delivering packets to or from MPLS-TP LSPs, PWs, and Sections, for delivering packets to or from MPLS-TP LSPs, PWs, and Sections,
are outside the scope of this document. are outside the scope of this document.
MPLS-TP packet encapsulation and forwarding operates according to the
MPLS data-plane architecture described in [RFC3031] and [RFC3032],
and the data-plane architectures for Single-Segment Pseudowires
[RFC3985], Multi-Segment Pseudowires [RFC5659], and Point-to-
Multipoint Pseudowires [I-D.ietf-pwe3-p2mp-pw-requirements], except
as noted otherwise in this document.
MPLS-TP forwarding is based on the label that identifies an LSP or
PW. The label value specifies the processing operation to be
performed by the next hop at that level of encapsulation. A swap of
this label is an atomic operation in which the contents of the packet
after the swapped label are opaque to the forwarder. The only event
that interrupts a swap operation is Time To Live (TTL) expiry.
Further processing to determine the context of a packet occurs when a
swap operation is interrupted in this manner, when a pop operation
exposes a specific reserved label, or when the packet is received
with the Generic Associated Channel Label (GAL) (see Section 4) at
the top of the stack. Otherwise the packet is forwarded according to
the procedures in [RFC3032].
3. MPLS-TP Transport Entities 3. MPLS-TP Transport Entities
The MPLS Transport Profile includes the following data-plane The MPLS Transport Profile includes the following data-plane
transport entities: transport entities:
o Label Switched Paths (LSPs) o Label Switched Paths (LSPs)
o Sections o Sections
o Pseudowires (PWs) o Pseudowires (PWs)
skipping to change at page 6, line 8 skipping to change at page 6, line 32
architecture [RFC3270]. Both E-LSP and L-LSP MPLS DiffServ modes are architecture [RFC3270]. Both E-LSP and L-LSP MPLS DiffServ modes are
included. The Traffic Class field (formerly the EXP field) of an included. The Traffic Class field (formerly the EXP field) of an
MPLS label follows the definition of [RFC5462] and [RFC3270] and MUST MPLS label follows the definition of [RFC5462] and [RFC3270] and MUST
be processed according to the rules specified in those documents. be processed according to the rules specified in those documents.
The Pipe and Short Pipe DiffServ tunneling and TTL processing models The Pipe and Short Pipe DiffServ tunneling and TTL processing models
described in [RFC3270] and [RFC3443] are included in the MPLS-TP. described in [RFC3270] and [RFC3443] are included in the MPLS-TP.
The Uniform model is outside the scope of the MPLS-TP. The Uniform model is outside the scope of the MPLS-TP.
Per-platform, per-interface or other context-specific label space Per-platform, per-interface or other context-specific label space
[RFC5331] MAY be used for MPLS-TP LSPs. Note that the requirements [RFC5331] MAY be used for MPLS-TP LSPs. Downstream [RFC3031] or
of a particular LSP type may dictate which label spaces it can use. upstream [RFC5331] label allocation schemes MAY be used for MPLS-TP
LSPs. Note that the requirements of a particular LSP type may
dictate which label spaces or allocation schemes it can use.
Per-packet Equal-Cost Multi-Path (ECMP) load-balancing is outside the Per-packet Equal-Cost Multi-Path (ECMP) load-balancing is outside the
scope of the MPLS-TP. scope of the MPLS-TP.
Penultimate Hop Popping (PHP) MUST be disabled by default on MPLS-TP Penultimate Hop Popping (PHP) MUST be disabled by default on MPLS-TP
LSPs. LSPs.
Fragmentation procedures as specified in [RFC3032] are outside the
scope of the MPLS-TP.
3.1.2. LSP Payloads 3.1.2. LSP Payloads
The MPLS-TP includes support for the following LSP payload types: The MPLS-TP includes support for the following LSP payload types:
o Network-layer protocol packets o Network-layer protocol packets
o Pseudowire packets o Pseudowire packets
The rules for processing LSP payloads that are network-layer protocol The rules for processing LSP payloads that are network-layer protocol
packets SHALL be as specified in [RFC3032] except as specifically packets SHALL be as specified in [RFC3032].
noted otherwise in this document.
The rules for processing LSP payloads that are pseudowire packets The rules for processing LSP payloads that are pseudowire packets
SHALL be as specified in [RFC3985] and the attendant standards SHALL be as specified in [RFC3985] and the attendant standards
defined by the IETF Pseudowire Emulation Edge-to-Edge (PWE3) Working defined by the IETF Pseudowire Emulation Edge-to-Edge (PWE3) Working
Group. Group.
Note that the payload of an MPLS-TP LSP may be a packet type that Note that the payload of an MPLS-TP LSP may be a packet type that
itself contains one or more MPLS labels. This is true, for instance, itself contains one or more MPLS labels. This is true, for instance,
when the payload is a pseudowire or another MPLS-TP LSP. From the when the payload is a pseudowire or another MPLS-TP LSP. From the
data-plane perspective, however, an MPLS-TP packet is an MPLS packet data-plane perspective, however, an MPLS-TP packet is an MPLS packet
skipping to change at page 7, line 51 skipping to change at page 8, line 23
3.2. Sections 3.2. Sections
Two MPLS-TP LSRs are considered to be topologically adjacent at a Two MPLS-TP LSRs are considered to be topologically adjacent at a
particular layer n >= 0 of the MPLS-TP LSP hierarchy if there exists particular layer n >= 0 of the MPLS-TP LSP hierarchy if there exists
a link between them at the next lowest network layer. Such a link, a link between them at the next lowest network layer. Such a link,
if it exists, will be either an MPLS-TP LSP (if n > 0) or a data-link if it exists, will be either an MPLS-TP LSP (if n > 0) or a data-link
provided by the underlying server layer network (if n = 0), and is provided by the underlying server layer network (if n = 0), and is
referred to as an MPLS-TP Section at layer n of the MPLS-TP LSP referred to as an MPLS-TP Section at layer n of the MPLS-TP LSP
hierarchy. Thus, the links traversed by a layer n+1 MPLS-TP LSP are hierarchy. Thus, the links traversed by a layer n+1 MPLS-TP LSP are
layer n MPLS-TP sections. layer n MPLS-TP sections. Such an LSP is referred to as a client of
the section layer, and the section layer as the server layer with
respect to its clients.
Note that the MPLS label stack associated with an MPLS-TP section at Note that the MPLS label stack associated with an MPLS-TP section at
layer n consists of n labels, in the absence of stack optimisation layer n consists of n labels, in the absence of stack optimisation
mechanisms such as PHP. Note also that in order for two LSRs to mechanisms such as PHP. Note also that in order for two LSRs to
exchange MPLS-TP control packets over a section, an additional label, exchange MPLS-TP control packets over a section, an additional label,
the Generic Associated Channel Label (GAL) (see Section 4) must the G-ACh Label (GAL) (see Section 4) must appear at the bottom of
appear at the bottom of the label stack. the label stack.
An MPLS-TP section may provide one or more of the following types of
service to its client layer:
o Point-to-point bidirectional
o Point-to-point unidirectional
o Point-to-multipoint unidirectional
The manner in which a section provides such a service is outside the
scope of the MPLS-TP.
Note that an LSP of any of the types listed in Section 3.1.3 may
serve as a section for a client-layer transport entity as long as it
supports the type of service the client requires.
3.3. Pseudowires 3.3. Pseudowires
The data-plane architectures for Single-Segment Pseudowires The data-plane architectures for Single-Segment Pseudowires
[RFC3985], Multisegment Pseudowires [RFC5659] and Point-to-Multipoint [RFC3985], Multi-Segment Pseudowires [RFC5659], and Point-to-
Pseudowires [I-D.ietf-pwe3-p2mp-pw-requirements], and the associated Multipoint Pseudowires [I-D.ietf-pwe3-p2mp-pw-requirements], and the
data-plane pseudowire protocol functions, as defined by the IETF associated data-plane pseudowire protocol functions, as defined by
Pseudowire Emulation Edge-to-Edge (PWE3) Working Group, are included the IETF Pseudowire Emulation Edge-to-Edge (PWE3) Working Group, are
in the MPLS-TP. included in the MPLS-TP.
This document specifies no modifications or extensions to pseudowire This document specifies no modifications or extensions to pseudowire
data-plane architectures or protocols. data-plane architectures or protocols.
4. MPLS-TP Generic Associated Channel 4. MPLS-TP Generic Associated Channel
The MPLS Generic Associated Channel (G-ACh) mechanism is specified in The MPLS Generic Associated Channel (G-ACh) mechanism is specified in
[RFC5586] and included in the MPLS-TP. The G-ACh provides an [RFC5586] and included in the MPLS-TP. The G-ACh provides an
auxiliary logical data channel associated with MPLS-TP Sections, auxiliary logical data channel associated with MPLS-TP Sections,
LSPs, and PWs in the data plane. The primary purpose of the G-ACh in LSPs, and PWs in the data plane. The primary purpose of the G-ACh in
the context of MPLS-TP is to support control, management, and OAM the context of MPLS-TP is to support control, management, and OAM
traffic associated with MPLS-TP transport entities. The G-ACh MUST traffic associated with MPLS-TP transport entities. The G-ACh MUST
NOT be used to transport client layer network traffic in MPLS-TP NOT be used to transport client layer network traffic in MPLS-TP
networks. networks.
5. Media-Specific Considerations For pseudowires, the G-ACh uses the first four bits of the PW control
word to provide the initial discrimination between data packets and
packets belonging to the associated channel, as described in
[RFC4385]. When this first nibble of a packet, immediately following
the label at the bottom of stack, has a value of '1', then this
packet belongs to a G-ACh. The first 32 bits following the bottom of
stack label then have a defined format called an Associated Channel
Header (ACH), which further defines the content of the packet. The
ACH is therefore both a demultiplexer for G-ACh traffic on the PW,
and a discriminator for the type of G-ACh traffic.
When the the control message is carried over a section or an LSP,
rather than over a PW, it is necessary to provide an indication in
the packet that the payload is something other than a client data
packet. This is achieved by including a reserved label with a value
of 13 in the label stack. This reserved label is referred to as the
G-ACh Label (GAL), and is defined in [RFC5586]. When a GAL is found,
it indicates that the payload begins with an ACH. The GAL is thus a
demultiplexer for G-ACh traffic on the section or the LSP, and the
ACH is a discriminator for the type of traffic carried on the G-ACh.
Note however that MPLS-TP forwarding follows the normal MPLS model,
and that a GAL is invisible to an LSR unless it is the top label in
the label stack. The only other circumstance under which the label
stack may be inspected for a GAL is when the TTL has expired. Any
MPLS-TP component that intentionally performs this inspection must
assume that it is asynchronous with respect to the forwarding of
other packets. All operations on the label stack are in accordance
with [RFC3031] and [RFC3032].
5. Server Layer Considerations
This section discusses considerations for support of the MPLS-TP data This section discusses considerations for support of the MPLS-TP data
plane by specific underlying server layer media. plane by server layer technologies and media.
5.1. Ethernet In general, the MPLS-TP network has no awareness of the internals of
the server layer of which it is a client, requiring only that the
server layer be capable of delivering the type of service required by
the MPLS-TP transport entities that make use of it. Note that what
appears to be a single server layer link to the MPLS-TP network may
be a complicated construct underneath, such as an LSP or a collection
of underlying links operating as a bundle. Special care may be
needed in network design and operation when such constructs are used
as a server layer for MPLS-TP.
5.1.1. Destination MAC Address Determination 5.1. Ethernet Media
5.1.1. Point-to-Point Links
When two MPLS-TP nodes are connected by a point-to-point Ethernet When two MPLS-TP nodes are connected by a point-to-point Ethernet
link, the question arises as to what destination Ethernet Media link, the question arises as to what destination Ethernet Media
Access Control (MAC) address should be specified in Ethernet frames Access Control (MAC) address should be specified in Ethernet frames
transmitted to the peer node over the link. The problem of transmitted to the peer node over the link. The problem of
determining this address does not arise in IP/MPLS networks because determining this address does not arise in IP/MPLS networks because
of the presence of the Ethernet Address Resolution Protocol (ARP) of the presence of the Ethernet Address Resolution Protocol (ARP)
[RFC0826] or IP version 6 Neighbor Discovery protocol [RFC4861], [RFC0826] or IP version 6 Neighbor Discovery protocol [RFC4861],
which allow the unicast MAC address of the peer device to be learned which allow the unicast MAC address of the peer device to be learned
dynamically. dynamically.
If existing mechanisms are available in an MPLS-TP network to If existing mechanisms are available in an MPLS-TP network to
determine the destination unicast MAC addresses of peer nodes - for determine the destination unicast MAC addresses of peer nodes - for
example if the network also happens to be an IP/MPLS network - such example if the network also happens to be an IP/MPLS network - such
mechanisms SHOULD be used. The remainder of this section discusses mechanisms SHOULD be used. The remainder of this section discusses
the available options when this is not the case. the available options when this is not the case.
One possibility is for each node to be statically configured with the One possibility is for each node to be statically configured with the
MAC address of its peer. Static MAC address configuration MAY be MAC address of its peer. Static MAC address configuration MAY be
used in an MPLS-TP network, but can present an administrative burden used in an MPLS-TP network, but can present an administrative burden
and lead to operational problems. and lead to operational problems. For example, replacement of an
Ethernet interface to resolve a hardware fault when this approach is
used requires that the peer node be manually reconfigured with the
new MAC address. This is especially problematic if the peer is
operated by another provider.
Another possibility is to use the Ethernet broadcast address, but Another possibility is to use the Ethernet broadcast address, but
this may lead to excessive frame distribution and processing at the this may lead to excessive frame distribution and processing at the
Ethernet layer. Broadcast traffic may also be treated specially by Ethernet layer. Broadcast traffic may also be treated specially by
some devices and this may not be desirable for MPLS-TP data frames. some devices and this may not be desirable for MPLS-TP data frames.
The preferred approach is therefore to use as the destination MAC The preferred approach is therefore to use as the destination MAC
address an Ethernet multicast address reserved for MPLS-TP. The address an Ethernet multicast address reserved for MPLS-TP for use
address allocated for this purpose by the Internet Assigned Numbers over point-to-point links. The address allocated for this purpose by
Authority (IANA) is 01-00-5E-XX-XX-XX. An MPLS-TP implementation the Internet Assigned Numbers Authority (IANA) is 01-00-5E-XX-XX-XX.
MUST process Ethernet frames received with this destination MAC An MPLS-TP implementation MUST process Ethernet frames received over
address by default. a point-to-point link with this destination MAC address by default.
[Editor's note: Decide what to say about multipoint Ethernet and Note that this approach is applicable only when the attached Ethernet
switched links. Decide if there is a need for protocol mechanisms to link is known to be point-to-point. If a link is not known to be
support learning of the Ethernet unicast MAC addresses of MPLS-TP point-to-point, the reserved MAC address noted above MUST NOT be
peers that are not also IP peers.] used.
5.2. Other Media A further alternative is to adapt or introduce a protocol mechanism
for learning the Ethernet unicast MAC addresses of MPLS-TP peers that
are not also IP peers. This topic is for further study.
[Editor's note: Decide whether any considerations for media other 5.1.2. Multipoint Links
than Ethernet need to be mentioned.]
When a multipoint Ethernet link serves as a section for a point-to-
multipoint MPLS-TP LSP, and multicast destination MAC addressing at
the Ethernet layer is used for the LSP, the addressing and
encapsulation procedures specified in [RFC5332] SHALL be used.
When a multipoint Ethernet link - that is, a link which is not known
to be point-to-point - serves as a section for a point-to-point
MPLS-TP LSP, unicast destination MAC addresses must be used for
Ethernet frames carrying packets of the LSP. Note that according to
the discussion in the previous section, this implies the use of
either static MAC address configuration or a protocol that enables
peer MAC address discovery.
6. Security Considerations 6. Security Considerations
TBD This document serves primarily to specify which aspects of existing
MPLS data-plane functionality apply to MPLS-TP. As such it
introduces no new security considerations in itself, but the security
considerations documented in the specifications to which it refers
apply as well to MPLS-TP.
7. IANA Considerations 7. IANA Considerations
A future version of this document will detail IANA considerations for The authors request that IANA allocate an Ethernet Multicast Address
the allocation of a standard Ethernet multicast MAC address for use from the Ethernet Multicast Addresses table in the ethernet-numbers
in MPLS-TP networks. registry for use by MPLS-TP LSRs over point-to-point links as
described in Section 5.1.1. The entry should specify an address of
the form 01-00-5E-XX-XX-XX, a Type Field of 8847/8848, and a usage
"MPLS-TP point-to-point (this draft)".
8. References 8. References
8.1. Normative References 8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031, January 2001. Label Switching Architecture", RFC 3031, January 2001.
skipping to change at page 11, line 5 skipping to change at page 13, line 13
RFC 5331, August 2008. RFC 5331, August 2008.
[RFC4875] Aggarwal, R., Papadimitriou, D., and S. Yasukawa, [RFC4875] Aggarwal, R., Papadimitriou, D., and S. Yasukawa,
"Extensions to Resource Reservation Protocol - Traffic "Extensions to Resource Reservation Protocol - Traffic
Engineering (RSVP-TE) for Point-to-Multipoint TE Label Engineering (RSVP-TE) for Point-to-Multipoint TE Label
Switched Paths (LSPs)", RFC 4875, May 2007. Switched Paths (LSPs)", RFC 4875, May 2007.
[RFC5332] Eckert, T., Rosen, E., Aggarwal, R., and Y. Rekhter, "MPLS [RFC5332] Eckert, T., Rosen, E., Aggarwal, R., and Y. Rekhter, "MPLS
Multicast Encapsulations", RFC 5332, August 2008. Multicast Encapsulations", RFC 5332, August 2008.
[RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
"Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
Use over an MPLS PSN", RFC 4385, February 2006.
8.2. Informative References 8.2. Informative References
[I-D.ietf-mpls-tp-framework] [I-D.ietf-mpls-tp-framework]
Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Bocci, M., Bryant, S., Frost, D., Levrau, L., and L.
Berger, "A Framework for MPLS in Transport Networks", Berger, "A Framework for MPLS in Transport Networks",
draft-ietf-mpls-tp-framework-10 (work in progress), draft-ietf-mpls-tp-framework-10 (work in progress),
February 2010. February 2010.
[I-D.ietf-pwe3-p2mp-pw-requirements] [I-D.ietf-pwe3-p2mp-pw-requirements]
Heron, G., Wang, L., Aggarwal, R., Vigoureux, M., Bocci, Heron, G., Wang, L., Aggarwal, R., Vigoureux, M., Bocci,
 End of changes. 29 change blocks. 
59 lines changed or deleted 164 lines changed or added

This html diff was produced by rfcdiff 1.38. The latest version is available from http://tools.ietf.org/tools/rfcdiff/