Network Working Group T. Nadeau (Ed)
Internet Draft C. Pignataro (Ed)
Intended status: Standards Track Cisco Systems, Inc.
Expiration Date: September 2007
R. Aggarwal (Ed)
Juniper Networks
March 2007
Pseudo Wire Virtual Circuit Connectivity Verification (VCCV)
draft-ietf-pwe3-vccv-13.txt
Status of this Memo
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Abstract
This document describes Virtual Circuit Connection Verification
(VCCV) which provides a control channel that is associated
with a Pseudowire (PW), as well as the corresponding
operations and management functions such as connectivity
verification to be used over that control channel. VCCV
applies to all supported access circuit and transport types
currently defined for PWs.
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Table of Contents
1 Specification of requirements .......................... 4
2 Introduction ........................................... 4
3 Overview of VCCV ....................................... 5
4 CC Types and CV Types ................................... 5
4.1 Bidirectional Forwarding Detection ...................... 7
4.1.1 BFD Encapsulation ....................................... 7
4.1.2 CV Types for BFD ........................................ 7
5 VCCV Control Channel for MPLS PSN ....................... 7
5.1 Inband VCCV (Type 1) .................................... 7
5.2 Out-of-Band VCCV (Type 2) ............................... 8
5.3 TTL Expiry VCCV (Type 3) ................................ 8
5.4 VCCV Connectivity Verification Types .................... 8
5.4.1 MPLS LSP Ping ........................................... 9
5.5 VCCV Capability Advertisement for MPLS PSN .............. 10
5.5.1 VCCV Capability Advertisement LDP Sub-TLV ............... 11
6 VCCV Control Channel for L2TPv3/IP PSN ................. 12
6.1 L2TPv3 VCCV Message .................................... 13
6.1.1 L2TPv3 VCCV using ICMP Ping ............................ 13
6.1.2 L2TPv3 VCCV using BFD .................................. 13
6.2 L2TPv3 VCCV Capability Indication ...................... 13
6.2.1 L2TPv3 VCCV Capability AVP ............................. 13
6.3 L2TPv3 VCCV Operation .................................. 14
7. Capability Advertisement Selection ..................... 14
8. IANA Considerations .................................... 14
8.1 VCCV Interface Parameters Sub-TLV ...................... 14
8.1.1 Control Channel Types (CC Types) ........................ 15
8.1.2 Connectivity Verification Types (CV Types) .............. 15
8.2 PW Associated Channel Type ............................. 15
8.3 L2TPv3 Assignments ..................................... 15
8.3.1 Control Message Attribute Value Pairs (AVPs) ........... 15
8.3.2 Default L2-Specific Sublayer bits ...................... 15
8.3.3 ATM-Specific Sublayer bits ............................. 15
8.3.4 VCCV Capability AVP Values ............................. 15
9 Security Considerations ................................ 15
10 Acknowledgements ....................................... 17
11 References ............................................. 17
11.1 Normative References ................................... 17
11.2 Informative References ................................. 18
12 Editors' Addresses ..................................... 18
13 Contributors' Addresses ................................ 19
14 Intellectual Property Statement ........................ 20
15 Full Copyright Statement ............................... 20
1. Specification of requirements
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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. Introduction
As network operators deploy Pseudowire (PW) services, fault detec-
tion and diagnostic mechanisms particularly for the PSN portion of
the network are pivotal. Specifically, the ability to provide end-to-
end fault detection and diagnostics for an emulated PW service is
critical for the network operator. Operators have indicated in
[RFC4377] [RFC3916] that such a tool is required for PW deployments.
This document describes procedures for a PSN-agnostic fault
detection and diagnostics tool called Virtual Circuit Connection
Verification (VCCV).
|<-------------- Emulated Service ---------------->|
| |<---------- VCCV ----------> |
| |<------- Pseudowire ------->| |
| | | |
| | |<-- PSN Tunnel -->| | |
| V V V V |
V AC +----+ +----+ AC V
+-----+ | | PE1|==================| PE2| | +-----+
| |----------|............PW1.............|----------| |
| CE1 | | | | | | | | CE2 |
| |----------|............PW2.............|----------| |
+-----+ ^ | | |==================| | | ^ +-----+
^ | +----+ +----+ | | ^
| | Provider Edge 1 Provider Edge 2 | |
| | | |
Customer | | Customer
Edge 1 | | Edge 2
| |
| |
Native service Native service
Figure 1: PWE3 VCCV Operation Reference Model
Figure 1 depicts the basic functionality of VCCV, and where it
resides within the PWE3 VCCV Operation Reference Model [RFC3985].
Customer Edge (CE) routers CE1 and CE2 are attached to the emulated
service via Access Circuits (ACs) to each of the Provider Edge (PE)
Routers (PE1 and PE2). These PEs are in-turn, connected via a
Pseudowire (PW) that traverses the provider network. VCCV provides
several means of creating a control channel between PE routers that
attach the PW.
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+-------------+ +-------------+
| Layer2 | | Layer2 |
| Emulated | < Emulated Service > | Emulated |
| Services | | Services |
+-------------+ +-------------+
| | VCCV/PW | |
|Demultiplexer| < Control Channel > |Demultiplexer|
+-------------+ +-------------+
| PSN | < PSN Tunnel > | PSN |
+-------------+ +-------------+
| Physical | | Physical |
+-----+-------+ +-----+-------+
| |
| ____ ___ ____ |
| _/ \___/ \ _/ \__ |
| / \__/ \_ |
| / \ |
---------| MPLS or IP Network |-----
\ /
\ ___ ___ __ _/
\_/ \____/ \___/ \____/
Figure 2: PWE3 Protocol Stack Reference Model
including the VCCV control channel.
Figure 2 depicts how the VCCV control channel is associated with the
Pseudowire. Ping and other IP messages are encapsulated using the
PWE3 encapsulation as described below in sections 5 and 6. These mes-
sages, referred to as VCCV messages, are exchanged only after the
desire to exchange such traffic has been negotiated between the PEs
(see Section 7.)
3. Overview of VCCV
VCCV defines a set of messages that are exchanged between PEs to ver-
ify connectivity of the Pseudowire. To make sure that VCCV packets
follow the same path as the PW data flow, they SHOULD be encapsulated
with the same PW demultiplexer and trasported over the same PSN
tunnel. For example, if MPLS is the PSN in use, then the same
label shim header (and label stack) MUST be incorporated. The only
cases where this might not be possible is when out-of-band VCCV modes
are used which require this encapsulation to be altered; however,
these modes are NOT RECOMMENDED.
VCCV can be used both as a fault detection and/or a diagnostic
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tool for Pseudowires. An operator can periodically invoke VCCV
for proactive connectivity verification on an active Pseudowire,
or on an ad hoc or as-needed as a means of manual
connectivity verification. When invoking VCCV, the operator
triggers a combination of one of its various Control Channel types
(CC Types) and one of its various Connectivity Verification types (CV
Types.) These include LSP-Ping, L2TPV3, or ICMP Ping [RFC0792] modes
and are applicable depending on the underlying PSN.
Since a Pseudowire service is bi-directional, the reply MAY be sent
in-band over the PW in the reverse direction. Responses MUST
be encapsulated so that they follow the return path of
the Pseudowire in this case. In-band responses MUST be attempted
first. If an in-band test fails, the operator is advised to
then use a subsequent test using an out-of-band reply mode such
as Reply Mode 4 from [RFC4379], which will return the result
to the sender via an application level control channel to
determine the fault's direction.
The control channel maintained with VCCV can carry fault detection
status across a Pseudowire and convey this information between
the endpoints of the Pseudowire. Furthermore, this information
can then be translated into the native OAM status codes used by
the native access technologies, such as ATM or Ethernet. The
specific details of such status interworking is out of the scope
of this document, and is only noted here to illustrate the
utility of VCCV for such purposes. More complete details can
be found in [OAM-MAP].
4. CC Types and CV Types
The VCCV Control Channel type (CC type) defines several possible
types of control channel that VCCV can support. These control
channels can in turn carry several types of protocols defined by the
Connectivity Verification type (CV type). VCCV potentially supports
multiple CV Types concurrently, but it only supports the use of a
single CC Type. The specific type or types of VCCV packets that can
be accepted and sent by a router are indicated during capability
advertisement as described in sections 5.5 and 6.2. The various VCCV
CV types supported MUST be used only when they apply to the context
of the PW demultiplexor in use. For example, LSP Ping type should
only be used when MPLS is utilized as the PSN.
Once a set of VCCV capabilities is received and advertised, a CC Type
and CV Type(s) that match both the received and transmitted
capabilites can be selected. That is, a PE router needs to only
allow Types that are both received and advertised to be selected,
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performing a logical AND between the received and transmitted bitflag
fields. The specific CC Type and CV Type(s) are then chosen within
the constraints and rules specified in Section 4.1.1, Section
4.1.2 and Section 7. Once a specific CC Type has been chosen (i.e.,
it matches both the transmitted and received VCCV CC capability),
transmitted and replied to, this CC Type MUST be the only one used
until such time as the Pseudowire is re-signaled. In addition, based
on these rules and the procedures defined in Section
5.2 of [RFC4447], the Pseudowire MUST be re-signaled if a different
set of capabilities types is desired.
The CC and CV type indicator fields are defined as a bitmasks
used to indicate the specific CC or CV type or types (i.e.: none,
one or more) of control channel packets that may be sent on the VCCV
control channel. These values represent the numerical value
corresponding to the actual bit being set in the bitfield. The
definition of each CC and CV Type is dependent on the context within
which it is defined; please refer to the specific MPLS or L2TPv3
sections below.
Control Channel (CC) Types:
The defined values for CC Types are for MPLS PWs are:
Bit 0 (0x01) - Type 1: PWE3 control word with 0001b
as first nibble as defined in [RFC4385].
Bit 1 (0x02) - Type 2: MPLS Router Alert Label.
Bit 2 (0x04) - Type 3: MPLS PW Demultiplexor Label
TTL = 1 (Type 3).
Bit 3 (0x08) - Reserved
Bit 4 (0x10) - Reserved
Bit 5 (0x20) - Reserved
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
The defined values for CC Types are for L2TPv3 PWs are:
Bit 0 (0x01) - L2-Specific Sublayer with V-bit set.
Bit 1 (0x02) - Reserved
Bit 2 (0x04) - Reserved
Bit 3 (0x08) - Reserved
Bit 4 (0x10) - Reserved
Bit 5 (0x20) - Reserved
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
Connectivity Verification (CV) Types:
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The defined values for CV Types are for MPLS PWs are:
Bit 0 (0x01) - ICMP Ping.
Bit 1 (0x02) - LSP Ping.
Bit 2 (0x04) - BFD for PW Fault Detection Only.
Bit 3 (0x08) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling.
Bit 4 (0x10) - BFD for PW Fault Detection Only. Carrying
BFD payload without IP headers.
Bit 5 (0x20) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling. Carrying BFD payload
without IP headers.
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
The defined values for CV Types are for L2TPv3 PWs are:
Bit 0 (0x01) - ICMP Ping.
Bit 1 (0x02) - Reserved
Bit 2 (0x04) - BFD for PW Fault Detection Only.
Bit 3 (0x08) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling.
Bit 4 (0x10) - BFD for PW Fault Detection Only. Carrying BFD
payload without IP headers.
Bit 5 (0x20) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling. Carrying BFD payload without
IP headers.
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
It should be noted that two pairs of CV Types have been defined when
BFD is used. See Section 4.1.1 and 4.1.2.
If none of the types above are supported, the entire CC and CV Type
Indicator fields SHOULD be transmitted as 0x00 (i.e.: all bits in the
bitfield set to 0) to indicate this to the peer.
If no capability is signaled, then the peer MUST assume that the peer
has no VCCV capability and follow the procedures specified in this
document for this case.
4.1 Bidirectional Forwarding Detection
When heart-beat indication is necessary for one or more PWs, the
Bidirectional Forwarding Detection (BFD) [BFD] provides a
means of continuous monitoring of the PW data path and
propagation of forward and reverse defect indications.
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In order to use BFD, both ends of the PW connection must have
signaled the existence of a common control channel and the ability to
run BFD on it. Once a node has both signaled and received signaling
from its peer of these capabilities and has chosen a single BFD CV
Type as specified in Section 4.1.2, it MUST begin sending BFD control
packets. The packets MUST be sent on the control channel. The use
of the control channel provides the context required to bind and
bootstrap the BFD session, thus single-hop BFD initialization
procedures are followed [BFD], and BFD MUST be run in asynchronous
mode [BFD].
When one of the PEs (PE2 from Figure 1) does not receive control
messages from its peer PE (PE1 from Figure 1) during a certain
number of transmission intervals (a number provisioned by the
operator) PE2 declares that the PW in its receive direction is down.
In other words, PE1 enters the "forward defect" state for this PW.
PE1 then sends a message to PE2 with H=0 (i.e. "I do not hear you")
and with Diagnostic code 1. In turn, PE2 declares the PW is down in
its transmit direction and it uses Diagnostic code 3 in its control
messages to PE1. PE2 enters the "reverse defect" state for this PW.
How it further processes this error condition, and conveys this
status the attachment circuits is out of the scope of this
specification, and is instead defined in [OAM-MAP].
The VCCV message comprises a BFD packet [BFD] encapsulated as
specified by the CV Type (see Section 4.1.1.)
4.1.1 BFD Encapsulation
VCCV defines two pairs of CV Types (see Section 4) which group two
ways in which the BFD Connectivity Verification packets may be
encapsulated. When the CV Type is either 0x04 or 0x08, the VCCV
encapsulation includes the IP/UDP encapsulation as defined in Section
4 of [BFD-V4V6-1HOP]. However, when either CV Type 0x10 or 0x20 are
employed, the IP/UDP headers are omitted. In this second group
(i.e., cases using CV Type 0x10 or 0x20), the corresponding PW
Associated Channel Header's or Layer-2 Specific Sublayer's Channel
Type field MUST use the value of PW-ACT-TBD defined in Section 8.2 as
a means of allowing the data plane to demultiplex the control channel
and identify the encased BFD payload.
Additionally, only the CC Type 1 (PWE3 Control Word with 0001b as
first nibble as defined in [RFC4385]) allows for the use of the BFD
encapsulation without the IP/UDP headers (i.e., using CV Types 0x10
or 0x20) in conjunction with other CV Types that include an IP
Header. That is, CV Types 0x10 or 0x20 MUST NOT be used along with
other CV Types, unless the CC Type in used is Type 1 (PWE3 Control
Word with 0001b as first nibble as defined in [RFC4385]). This
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restriction stems from the fact that Type 1 is the only CC Type that
contains a Protocol Identification (PID) field, the Associated
Channel Type. If it is desired to concurrently have BFD along with a
CV Type that includes an IP Header (e.g., LSP Ping), over a Control
Channel utilizing CC Types 2 or 3, then only BFD encapsulations
including IP/UDP headers (i.e., CV Types 0x04 or 0x08) can be used.
4.1.2 CV Types for BFD
As with other CV Types, and given the bidirectional nature of BFD,
before selecting a given BFD CV Type capability to be used, there
MUST be a match in the given CV Type capability advertised and
received. That is, only BFD CV Types that were both advertised and
received are available to be selected. Additionally, only one BFD CV
Type can be used (selecting a BFD CV Type excludes all the rest BFD
CV Types). The following list enumerates restrictions on the usage
of BFD CV Types:
1. In the case of CV Type 0x08 or 0x20, the AC and PW status SHOULD
be conveyed via BFD status codes as specified in [OAM-MAP].
2. The CV Types 0x08 and 0x20, however, SHOULD NOT be used when a
control protocol such as LDP or L2TPV3 is available that can
signal the AC/PW status to the remote endpoint of the PW
[RFC4447].
3. In the case of type 0x04 or 0x10, BFD is used exclusively to
detect faults on the PW and the status of those faults SHOULD be
conveyed using some means other than BFD, such as using LDP
status messages when using MPLS as a transport (see [RFC4447]),
or the Circuit Status AVP in an L2TPv3 SLI message for L2TPv3
(see [RFC3931].)
4. Similarly, CV Types 0x04 and 0x10 SHOULD NOT be used when there
is no control protocol available to signal the AC/PW status.
5. Only a single BFD CV Type can be seleced and used.
5. VCCV Control Channel for MPLS PSN
When MPLS is used to transport PW packets, VCCV packets are
carried over the MPLS LSP as defined in this section.
In order to apply IP monitoring tools a PWE3 PW, an operator
may configure VCCV as a control channel for the PW between
the PEs endpoints [RFC3985]. Packets sent across this channel
from the source PE towards the destination PE either as in-band
traffic with the PW's data, or out-of-band. In all cases, the
control channel traffic MUST NOT be forwarded past the PE
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endpoints towards the Customer Edge (CE) devices; instead,
they must be intercepted at the PE endpoints for exception
processing.
The capability of which control channel type (CC Type) to
use is advertised by a PE to indicate which of the various
control channel types are supported. Once the receiving PE
has chosen a CC Type mode to use, it MUST continue using this mode
until such time as the PW is re-signaled. Thus, if a new CC
type is desired, the PW must be torn-down and re-established.
Ideally such a control channel would be completely inband. When
a control word is present on the PW, it is possible to indicate the
control channel by setting a bit in the control word header.
The following subsections define each of the currently defined VCCV
Control Channel Types (CC Types).
5.1. Inband VCCV (Type 1)
The PW set-up protocol [RFC4447] determines whether a PW uses a
control word. When a control word is used, it SHOULD have the
following form for the purpose of indicating VCCV control
channel messages. Note that for data, one uses the control
word defined just above the MPLS payload [RFC4385].
The PW Associated Channel for VCCV control channel traffic is
defined as follows in [RFC4385]:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | Channel Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: PW Associated Channel Header
The first nibble is set to 0001b to indicate a channel associated
with a Pseudowire [RFC4385][RFC4446]. The Version and the Reserved
fields are set to 0, and the Channel Type is set to 0x0021 for
IPv4 and 0x0057 for IPv6 payloads. If the payload contains
BFD without IP/UDP headers, it MUST use PW-ACT-TBD as the Channel
Type (see Section 8.2.)
For example, the following is an example of how the ethernet
ACH would be received [RFC4448] containing an LSP Ping payload
corresponding to a choice of CC Type of 0x01 and a CV Type of
0x02:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|0 0 0 0|0 0 0 0 0 0 0 0| 0x21 (IPv4) or 0x57 (IPv6) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: PW Associated Channel Header for VCCV
It should be noted that although some PW types are not required
to carry the control word, this type of VCCV MUST only be used
for those PW types that do employ the control word when it is
in use. Additionally, this is the only CC Type mode that allows the
concurrent usage of CV Types that are encapsulated with an IP Header
(e.g., LSP Ping) along with other CV Types that lack an IP Header
(e.g., BFD encapsulation as per CV Types 0x10 or 0x20.)
This is the preferred mode of VCCV operation when the control word
is present.
5.2. Out-of-Band VCCV (Type 2)
A VCCV control channel can alternatively be created by using the
MPLS router alert label [RFC3032] immediately above the PW label.
It should be noted that this approach MAY result in a differnt
equal cost multi-path (ECMP) hashing behavior than Pseudowire
PDUs and thus result in the VCCV control channel traffic taking
a path which differs from that of the actual data traffic under
test.
This is the preferred mode of VCCV operation when the control word
is not present.
5.3. TTL Expiry VCCV (Type 3)
The TTL of the PW label can be set to 1 to force the packet to be
processed within the destination router's control plane. This is
an inband control channel identification mechanism that is an
alternate to Section 5.1.
To use this type, the control word MUST be used.
5.4 VCCV Connectivity Verification Types
5.4.1 MPLS LSP Ping
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The LSP Ping header MUST be used in accordance with [RFC4379]
and MUST also contain the target FEC Stack containing the
sub-TLV of 8 for the "L2 VPN endpoint", 9 (deprecated) or 10 for
"FEC 128 Pseudowire" or 11 for the "FEC 129 Pseudowire". The
sub-TLV indicates the PW to be verified.
5.5 VCCV Capability Advertisement for MPLS PSN
To permit the indication of the type or types of PW control
channel(s) and connectivity verification mode or modes over a
particular PW, a VCCV parameter is defined below that is used as part
of the PW establishment signaling. When a PE signals a PW and
desires PW OAM for that PW, it MUST indicate this during PW
establishment using the messages defined below. Specifically, for PE
MUST include the VCCV interface parameter sub-TLV (0x0C) assigned in
[RFC4446] in the PW setup message [RFC4447].
The decision of the type of VCCV control channel is left completely
to the receiving control entity, although the set of choices is
given by the sender in that it indicates the type or types of
control channels and connectivity verification types that it can
understand. The receiver SHOULD chose a single Control Channel type
from the match between the choices sent and received, based on the
capability advertisement selection specified below in Section 7, and
it MUST continue to use this type for the duration of the life of the
control channel. Changing Control Channel types after one has been
established to be in use could potentially cause problems at the
receiving end, and could also lead to interoperability issues, thus
it is NOT RECOMMENDED.
When a PE sends a label mapping message for a PW, it uses
the VCCV parameter to indicate the type of OAM control channels
and connectivity verification type or types it is willing to receive
and can send on that PW. The capablity of supporting a control
channel or channels, and connectivity type or types used over that
control channel or channels MUST be signaled before the remote PE may
send VCCV messages, and then it can do so only on the control channel
or channels, and using the connectivity verification type or types
indicated.
If a PE receives VCCV messages prior to advertising capability for
this message, it MUST discard these messages and not reply to them.
In this case, the PE SHOULD increment an error counter and optionally
issue a system and/or SNMP notification to indicate to the system
administrator that this condition exists.
When LDP is used as the PW signaling protocol the requesting PE
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indicates its configured VCCV capability or capabilities to the
remote PE by including the VCCV parameter with appropriate options
indicating which control channel and connectivity verification types
it supports in the VCCV interface parameter sub-TLV field of the PW
ID FEC TLV (FEC 128) or in the interface parameter sub-TLV of the
Genralized PW ID FEC TLV (FEC 129). The requesting PE MAY indicate
that it supports multiple control channel options, and in doing so
agrees to support any and all indicated types if transmitted to it,
but MUST do so in accordance with the rules stipulated in Section
5.5.1 (VCCV Capability Advertisement Sub-TLV.)
Local policy may direct the PE to support certain OAM capability and
to indicate it. The absence of the VCCV parameter indicates that no
OAM functions are supported by the requesting PE, and thus the
receiving PE MUST NOT send any VCCV control channel traffic to it.
The reception of a VCCV parameter with no options set MUST be
ignored as if one is not transmitted at all.
The receiving PE similarly indicates its supported control channel
types in the label mapping message. These may or may not be the same
as the ones that were sent to it. The sender should examine the set
that is returned to understand which control channels it may
establish with the remote peer, as specoified in Section 4 and
Section 7. Similarly, it MUST NOT send control channel traffic to
the remote PE for which the remote PE has not indicated it supports.
5.5.1 VCCV Capability Advertisement LDP Sub-TLV
[RFC4447] defines an Interface Parameter Sub-TLV in the LDP PW ID
FEC (FEC 128) and an Interface Parameters TLV in the LDP Generalized
PW ID FEC (FEC 129) to signal different capabilities for specific
PWs. An optional sub-TLV parameter is defined to indicate the
capability of supporting none, one or more control channel and
connectivity verification types for VCCV. This is the VCCV parameter
field. If FEC 128 is used the VCCV parameter field is carried in the
Interface Parameter sub-TLV. field If FEC 129 is used it is carried
as an Interface Parameter sub-TLV in the Interface Parameters TLV.
The VCCV parameter ID is defined as follows in [RFC4446]:
Parameter ID Length Description
0x0c 4 VCCV
The format of the VCCV parameter field is as follows:
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
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x0c | 0x04 | CC Types | CV Types |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Control Channel (CC Types) type field defines a bitmask used to
indicate the type of control channel(s) (i.e.: none, one or more)
that a router is capable of receiving control channel traffic on.
If more than one control channel is specified, the router agrees
to accept control traffic over either control channel; however, see
the rules specified in Section 4 and Section 7 for more details.
If none of the types are supported, a CC Type Indicator of 0x00
SHOULD be transmitted to indicate this to the peer. However,
if no capability is signaled, then the PE MUST assume that its
peer is incapable of receiving any of the VCCV CC Types and
MUST NOT send any OAM control channel traffic to it. Note that
the CC and CV types definitions are consistent regardless of
the PW's transport or access circuit type. The CC and CV values
are defined in Section 4.
6. VCCV Control Channel for L2TPv3/IP PSN
When L2TPv3 is used to setup a PW over an IP PSN, VCCV packets are
carried over the L2TPv3 session as defined in this section. L2TPv3
provides a "Hello" keepalive mechanism for the L2TPv3 control plane
that operates in-band over IP or UDP (see Section 4.4 of [RFC3931].)
This built-in Hello facility provides dead peer and path detection
only for the group of sessions associated with the L2TP Control
Connection. VCCV, however, allows individual L2TP sessions to be
tested. This provides a more granular mechanism which can be used to
troubleshoot potential problems within the dataplane of L2TP
endpoints themselves, or to provide additional connection status of
individual Pseudowires.
The capability of which control channel type (CC Type) to use is
advertised by a PE to indicate which of the potentially various
control channel types are supported. Once the receiving PE
has chosen a mode to use, it MUST continue using this mode
until such time as the PW is re-signaled. Thus, if a new CC
type is desired, the PW must be torn-down and re-established.
In order to carry VCCV messages within an L2TPv3 session data packet,
the PW MUST be established such that an L2-Specific Sublayer (L2SS)
that defines the V-bit is present. This document defines the V-bit
for the Default L2-Specific Sublayer [RFC3931] and the ATM-Specific
Sublayer [RFC4454] using the Bit 0 position (see Section 8.3.2 and
Section 8.3.3.) The L2-Specific Sublayer presence and type (either
the Default or a PW-Specific L2SS) is signaled via the L2-Specific
Sublayer AVP, Attribute Type 69, as defined in [RFC3931]. The V-bit
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within the L2-Specific Sublayer is used to identify that a VCCV
message follows, and when the V-bit is set the L2SS has the following
format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1|0 0 0|Version| Reserved | Channel Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
L2-Specific Sublayer Format when the V-bit (bit 0) is set
The VCCV messages are distinguished from user data by the V-bit. The
V-bit is set to 1, indicating that a VCCV session message follows.
The next three bits MUST be set to 0 when sending and ignored upon
receipt. The remaining fields comprising 28 bits (i.e., Version,
Reserved and Channel Type) follow the same definition, format and
number registry from Section 5 of [RFC4385].
Depending on the CV Type in use, the Channel Type can indicate IPv4,
IPv6 (see [RFC4385]) or BFD (see Section 8.2) as VCCV payload
directly following the L2SS. For CV Types of 0x01, 0x04 and 0x08,
the Channel Type can indicate IPv4 (0x21) or IPv6 (0x57); for CV
Types of 0x10 and 0x20, the Channel Type indicates BFD Without IP/UDP
Header (PW-ACT-TBD).
6.1. L2TPv3 VCCV Message
The VCCV message over L2TPv3 directly follows the L2-Specific
Sublayer with the V-bit set. It could either contain an ICMP Echo
packet as described in Section 6.1.1, or a BFD packet as described in
Section 6.1.2.
6.1.1. L2TPv3 VCCV using ICMP Ping
When this connectivity verification mode is used, an ICMP Echo packet
[RFC0792] achieves connectivity verification. The ICMP Ping packet
directly follows the L2SS with the V-bit set. In the ICMP Echo
request, the IP Header fields MUST have the following values: the
destination IP address is set to the remote LCCE's IP address for the
tunnel endpoint, the source IP address is set to the local LCCE's IP
address for the tunnel endpoint, and the TTL is set to 1.
6.1.2. L2TPv3 VCCV using BFD
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The L2TPv3 Session ID provides the context to demultiplex the first
BFD control packet. See Section 4.1, Section 4.1.1 and Section
4.1.2 for additional details on BFD usage, BFD encapsulation and BFC
CV Types.
6.2. L2TPv3 VCCV Capability Indication
A new optional AVP is defined in Section 6.2.1 to indicate the
VCCV capabilities during session establishment. An LCCE MUST signal
its desire to use connectivity verification for a particular L2TPv3
session and its VCCV capabilities using the VCCV Capability AVP.
6.2.1. L2TPv3 VCCV Capability AVP
The "VCCV Capability AVP", Attribute type AVP-TBD, specifies the VCCV
capabilities as a pair of bitflags for the Control Channel (CC) and
Connectifity Verification (CV) Types. This AVP is exchanged during
session establishment (in ICRQ, ICRP, OCRQ or OCRP messages). The
value field has the following format:
VCCV Capability AVP (ICRQ, ICRP, OCRQ, OCRP)
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CC Types | CV Types |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
CC Types:
The Control Channel (CC) Types field defines a bitmask used to
indicate the type of control channel(s) that may be used to
receive OAM traffic on for the given Session. The router agrees
to accept VCCV traffic at any time over any of the signaled VCCV
control channel types. CC Type values are defined in Section 4.
Although there is only one value defined in this document, the CC
Types field is included for forward compatibility should further
CC Types need to be defined in the future.
A CC Type of 0x01 may only be requested when there is an
L2-Specific Sublayer that defines the V-bit present. If a CC Type
of 0x01 is requested without requesting an L2-Specific Sublayer
AVP with an L2SS type that defines the V-bit, the session MUST be
disconnected with a CDN message.
If no CC Type is supported, a CC Type Indicator of 0x00 SHOULD be
sent.
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CV Types:
The Connectifity Verification (CV) Types field defines a bitmask
used to indicate the specific type or types (i.e.: none, one or
more) of control packets that may be sent on the specified VCCV
control channel. CV Type values are defined in Section 4.
If no VCCV Capability AVP is signaled, then the LCCE MUST assume that
the peer is incapable of receiving VCCV and MUST NOT send any OAM
control channel traffic to it.
All L2TP AVPs have an M (Mandatory) bit, H (Hidden) bit, Length, and
Vendor ID. The Vendor ID for the VCCV Capability AVP MUST be 0,
indicating that this is an IETF-defined AVP. This AVP MAY be hidden
(the H bit MAY be 0 or 1). The M bit for this AVP SHOULD be set to
0. The Length (before hiding) of this AVP is 8.
6.3. L2TPv3 VCCV Operation
An LCCE sends VCCV messages on an L2TPv3 signaled Pseudowire for
fault detection and diagnostic of the L2TPv3 session. The VCCV
message travels inband with the Session and follows the exact same
path as the user data for the session, because the IP header and
L2TPv3 Session header are identical. The egress LCCE of the L2TPv3
session intercepts and processes the VCCV message, and verifies the
signaling and forwarding state of the Pseudowire on reception of the
VCCV message. Any faults detected can be signaled in the VCCV
response. It is to be noted that the VCCV mechanism for L2TPv3 is
primarily targeted at verifying the Pseudowire forwarding and
signaling state at the egress LCCE. It also helps when L2TPv3 Control
Connection and Session paths are not identical.
An LCCE MUST NOT send VCCV packets on an L2TPv3 session unless it has
received VCCV capability by means of the VCCV Capability AVP from the
remote end. If an LCCE receives VCCV packets and its not VCCV
capable or it has not sent VCCV capability indication to the remote
end, it MUST discard these messages. It should also increment an
error counter. In this case the LCCE MAY optionally issue a system
and/or SNMP notification.
As specified in Section 4, CV Types sent and received need to match
in order to be used. Specifically, and also because BFD is
bidirectional in nature, when using BFD as the connectivity
verification type, an LCCE must send VCCV packets on an L2TPv3
session only if it has signaled VCCV capability with a BFD CV Type to
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the remote end and received VCCV capability with a matching BFD CV
Type from the remote end.
7. Capability Advertisement Selection
When a PE receives a VCCV capability advertisement, the advertisement
may potentially contain more than one CC or CV Type. Only matching
capabilities can be selected. When multiple capabilities match, only
one CC Type MUST be used, and the CV Type or CV Types to be used
MUST follow the restrictions described in sections 4, 4.1.1 and
4.1.2.
In particular, once a valid CC Type is used by a PE (traffic sent
using that encapsulation), the PE MUST NOT send any traffic down
another CC Type control channel.
For cases were multiple CC Types are advertised, the following
precedence rules apply when choosing the single CC Type to use:
0x01 - PWE3 control word with 0001b as first nibble
0x04 - MPLS PW Demultiplexor Label TTL = 1
0x02 - MPLS Router Alert Label
The selection of the BFD CV Type to use out of the four BFD CV Types
defined in this document is tied to multiple factors: Given that BFD
is bidirectional in nature, only CV Types that are both received and
sent in VCCV capability signaling advertisement can be selected.
When a control protocol that can signal the AC/PW status is not
available, CV Types CV Types 0x04 and 0x10 SHOULD NOT be used. When a
control protocol that can signal the AC/PW status (such as LDP
[RFC4447] or L2TPv3 [RFC3931]) is available, CV Types 0x08 and 0x20
SHOULD NOT be used. All BFD CV Types are mutually exclusive with the
rest, and selecting a BFD CV Type prevents the use of any of the
other three BFD CV Types. Finally, only CC Type 0x01 (for both MPLS
and L2TPv3) supports the concurrent use of BFD CV Types 0x10 or 0x20
along with another CV Type that uses an encapsulation with IP
headers. Therefore, if it is desired to use a CV Type of 0x10 or
0x20 simultaneously with a CV Type that uses IP Headers, then CC Type
0x01 MUST be used.
8. IANA Considerations
8.1. VCCV Interface Parameters Sub-TLV
The VCCC Interface Parameters Sub-TLV codepoint is defined in
[RFC4446]. IANA is requested to create and maintain registries for
the CC Types and CV Types (bitmasks in the VCCV Parameter ID). The CC
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Type and CV Type new registries (see Section 8.1.1 and 8.1.2
respectively) are to be created in the Pseudo Wires Name Spaces,
reachable from <http://www.iana.org/assignments/pwe3-parameters>.
The allocations must be done using the "IETF Consensus" policy
defined in RFC2434.
8.1.1. Control Channel Types (CC Types)
IANA is requested to set up a registry of "VCCV Control Channel
Types". These are 8 bitfield values. CC Type values 0x01, 0x02, and
0x04 are specified in Section 4 of this document. The remaining
bitfield values (0x08, 0x10, 0x20, 0x40 and 0x80) are to be assigned
by IANA using the "IETF Consensus" policy defined in [RFC2434]. A
VCCV Control Channel Type description and a reference to an RFC
approved by the IESG are required for any assignment from this
registry.
Bit 0 (0x01) - Type 1: PWE3 control word with 0001b
as first nibble as defined in [RFC4385].
Bit 1 (0x02) - Type 2: MPLS Router Alert Label.
Bit 2 (0x04) - Type 3: MPLS PW Demultiplexor Label
TTL = 1 (Type 3).
Bit 3 (0x08) - Reserved
Bit 4 (0x10) - Reserved
Bit 5 (0x20) - Reserved
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
8.1.2. Connectivity Verification Types (CV Types)
IANA is requested to set up a registry of "VCCV Control Verification
Types". These are 8 bitfield values. CV Type values 0x01, 0x02, 0x04
0x08, 0x10 and 0x20 are specified in Section 4 of this document. The
remaining bitfield values (0x40 and 0x80) are to be assigned by IANA
using the "IETF Consensus" policy defined in [RFC2434]. A VCCV
Control Verification Type description and a reference to an RFC
approved by the IESG are required for any assignment from this
registry.
Bit 0 (0x01) - ICMP Ping.
Bit 1 (0x02) - LSP Ping.
Bit 2 (0x04) - BFD for PW Fault Detection Only.
Bit 3 (0x08) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling.
Bit 4 (0x10) - BFD for PW Fault Detection Only. Carrying
BFD payload without IP headers.
Bit 5 (0x20) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling. Carrying BFD payload
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without IP headers.
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
8.2 PW Associated Channel Type
The PW Associated Channel Types used by VCCV as defined above in
sections 4.1, 4.2 and 4.3 rely on previously allocated numbers from
the Pseudowire Associated Channel Types Registry [RFC4385] in the
Pseudo Wires Name Spaces reachable from
<http://www.iana.org/assignments/pwe3-parameters>. In particular,
0x21 (Internet Protocol version 4) MUST be used whenever an IPv4
payload follows the Pseudowire Associated Channel Header, or 0x57
MUST be used when an IPv6 payload follows the Pseudowire Associated
Channel Header.
In cases where raw BFD follows the Pseudowire Associated Channel
Header (i.e.: the IP/UDP encapsulation as specified in [BFD]
will not be present), a new Pseudowire Associated Channel Types
Registry [RFC4385] entry of PW-ACT-TBD is used. IANA is requested to
reserve a new Channel Types value as follows:
Value (in hex) Protocol Name Reference
-------------- ------------------------------- ---------
PW-ACT-TBD BFD Without IP/UDP Header [This document]
8.3. L2TPv3 Assignments
Sections 8.3.1 through 8.3.3 are registrations of new L2TP values for
registries already managed by IANA. Section 8.3.4 requests a new
registry to be added to the existing L2TP name spaces, and be
maintained by IANA accordingly. The Layer Two Tunneling Protocol
"L2TP" Name Spaces are reachable from
<http://www.iana.org/assignments/l2tp-parameters>.
8.3.1. Control Message Attribute Value Pairs (AVPs)
An additiona AVP Attribute is specified in Section 6.2.1. It is
required to be defined by IANA as described in Section 2.2 of
[RFC3438].
Attribute
Type Description
--------- ----------------------------------
AVP-TBD VCCV Capability AVP
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8.3.2. Default L2-Specific Sublayer bits
The Default L2-Specific Sublayer contains 8 bits in the low-order
portion of the header. This document defines one reserved bits in
the Default L2-Specific Sublayer in Section 6, which may be assigned
by IETF Consensus [RFC2434]. It is required to be assigned by IANA.
Default L2-Specific Sublayer bits - per [RFC3931]
---------------------------------
Bit 0 - V (VCCV) bit
8.3.3. ATM-Specific Sublayer bits
The ATM-Specific Sublayer contains 8 bits in the low-order portion of
the header. This document defines one reserved bits in the ATM-
Specific Sublayer in Section 6, which may be assigned by IETF
Consensus [RFC2434]. It is required to be assigned by IANA.
ATM-Specific Sublayer bits - per [RFC4454]
--------------------------
Bit 0 - V (VCCV) bit
8.3.4. VCCV Capability AVP Values
This is a new registry for IANA to maintain in the L2TP Name Spaces.
IANA is requested to maintain a registry for the CC Types and CV
Types bitmasks in the VCCV Capability AVP, defined in Section 6.2.1.
The allocations must be done using the "IETF Consensus" policy
defined in [RFC2434]. A VCCV CC or CV Type description and a
reference to an RFC approved by the IESG are required for any
assignment from this registry.
IANA is requested to reserve the following bits in this registry:
VCCV Capability AVP (Attribute Type AVP-TBD) Values
---------------------------------------------------
Control Channel (CC) Types
Bit 0 (0x01) - L2-Specific Sublayer with V-bit set.
Bit 1 (0x02) - Reserved
Bit 2 (0x04) - Reserved
Bit 3 (0x08) - Reserved
Bit 4 (0x10) - Reserved
Bit 5 (0x20) - Reserved
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
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Connectifity Verification (CV) Types
Bit 0 (0x01) - ICMP Ping
Bit 1 (0x02) - Reserved
Bit 2 (0x04) - BFD for PW Fault Detection Only.
Bit 3 (0x08) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling.
Bit 4 (0x10) - BFD for PW Fault Detection Only. Carrying
BFD payload without IP headers.
Bit 5 (0x20) - BFD for PW Fault Detection and AC/PW Fault
Status Signaling. Carrying BFD payload
without IP headers.
Bit 6 (0x40) - Reserved
Bit 7 (0x80) - Reserved
9. Security Considerations
Routers that implement the mechanism described herein are subject to
to additional denial-of-service attacks as follows:
An intruder may impersonate an LDP peer in order to
force a failure and reconnection of the TCP connection.
Please see the Security Considerations section of
[RFC3036] details.
An intruder could intercept or inject VCCV packets effectively
providing false positives or false negatives.
An intruder could deliberately flood a peer router with VCCV
messages to either obtain services without authorization or to
deny services to others.
A misconfigured or misbehaving device could inadvertantly flood
a peer router with VCCV messages which could result in a denial
of services. In particular, if a router is either implicitly or
explicitly indicated that it cannot support one or all of the
types of VCCV, but is sent those messages in sufficient quantity,
could result in a denial of service.
All of attacks above which concern the L2TPv3 or LDP control planes
may be countered by use of a control message authentication scheme
between LDP or L2TPv3 peers, such as the MD5-based scheme outlined in
[RFC3036] or the MD5 or SHA-1 based schemes described in [RFC3931] to
provide mutual peer authentication and individual control message
integrity and authenticity checking (see Section 8.1 of [RFC3931]).
Implementation of IP source address filters may also aid in deterring
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these types of attacks.
VCCV message throttling mechanisms should be employed, especially in
distributed implementations which have a centralized control plane
processor with various line cards attached by some data path. In
these architectures VCCV messages may be processed on the central
processor after being forwarded there by the receiving line card. In
this case, the path between the line card and the control processor
may become saturated if appropriate VCCV traffic throttling is not
employed, which could lead to a denial of service. Such filtering is
also useful for preventing the processing of unwanted VCCV messages,
such as those which are sent on unwanted (and perhaps unadvertised)
control channel types or VCCV types.
VCCV spoofing requires MPLS PW label spoofing and spoofing the PSN
tunnel header. As far as the PW label is concerned the same consider-
ations as specified in [RFC3031] apply. If the PSN is a MPLS tunnel,
PSN tunnel label spoofing is also required. For L2TPv3, data packet
spoofing considerations are outlined in Section 8.2 of [RFC3931].
While the L2TPv3 Session ID provides traffic separation, the optional
Cookie provides additional protection to thwarts spoofing attacks. To
maximize protection against a variety of dataplane attacks, a 64-bit
cookie can be used. L2TPv3 can also be run over IPsec as detailed in
Section 4.1.3 of [RFC3931].
10. Acknowledgements
The authors would like to thank Hari Rakotoranto, Michel Khouderchah,
Bertrand Duvivier, Vanson Lim, Chris Metz, W. Mark Townsley, Eric
Rosen, Dan Tappan, Danny McPherson, Luca Martini, Don O'Connor, Neil
Harrison, Danny Prairie and Mustapha Aissaoui for their valuable
comments and suggestions.
11. References
11.1. Normative References
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031, January 2001.
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
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Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, January 2001.
[RFC3036] Andersson, L., Doolan, P., Feldman, N., Fredette, A., and
B. Thomas, "LDP Specification", RFC 3036, January 2001.
[RFC3931] Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling
Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.
[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.
[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge
Emulation (PWE3)", BCP 116, RFC 4446, April 2006.
[RFC4447] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G.
Heron, "Pseudowire Setup and Maintenance Using the Label
Distribution Protocol (LDP)", RFC 4447, April 2006.
[RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", RFC 4379,
February 2006.
[BFD] Katz, D. and D. Ward, "Bidirectional Forwarding
Detection", draft-ietf-bfd-base-05 (work in progress),
June 2006.
11.2. Informative References
[RFC4377] Nadeau, T., Morrow, M., Swallow, G., Allan, D., and S.
Matsushima, "Operations and Management (OAM) Requirements
for Multi-Protocol Label Switched (MPLS) Networks",
RFC 4377, February 2006.
[RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to-
Edge (PWE3) Architecture", RFC 3985, March 2005.
[RFC3916] Xiao, X., McPherson, D., and P. Pate, "Requirements for
Pseudo-Wire Emulation Edge-to-Edge (PWE3)", RFC 3916,
September 2004.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
[OAM-MAP] Nadeau, T., "Pseudo Wire (PW) OAM Message Mapping",
draft-ietf-pwe3-oam-msg-map-04 (work in progress),
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March 2006.
[RFC3438] Townsley, W., "Layer Two Tunneling Protocol (L2TP)
Internet Assigned Numbers Authority (IANA) Considerations
Update", BCP 68, RFC 3438, December 2002.
[RFC4448] Martini, L., Rosen, E., El-Aawar, N., and G. Heron,
"Encapsulation Methods for Transport of Ethernet over MPLS
Networks", RFC 4448, April 2006.
[RFC4454] Singh, S., Townsley, M., and C. Pignataro, "Asynchronous
Transfer Mode (ATM) over Layer 2 Tunneling Protocol
Version 3 (L2TPv3)", RFC 4454, May 2006.
[BFD-V4V6-1HOP]
Katz, D. and D. Ward, "BFD for IPv4 and IPv6 (Single
Hop)", draft-ietf-bfd-v4v6-1hop-05 (work in progress),
June 2006.
12. Editors' Addresses
Thomas D. Nadeau
Cisco Systems, Inc.
300 Beaver Brook Road
Boxborough, MA 01719
Email: tnadeau@cisco.com
Carlos Pignataro
Cisco Systems, Inc.
7025 Kit Creek Road
PO Box 14987
Research Triangle Park, NC 27709
EMail: cpignata@cisco.com
Rahul Aggarwal
Juniper Networks
1194 North Mathilda Ave.
Sunnyvale, CA 94089
Email: rahul@juniper.net
13. Contributors' Addresses
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George Swallow
Cisco Systems, Inc.
300 Beaver Brook Road
Boxborough, MA 01719
Email: swallow@cisco.com
Monique Morrow
Cisco Systems, Inc.
Glatt-com
CH-8301 Glattzentrum
Switzerland
Email: mmorrow@cisco.com
Yuichi Ikejiri
NTT Communication Corporation
1-1-6, Uchisaiwai-cho, Chiyoda-ku
Tokyo 100-8019
Shinjuku-ku, JAPAN
Email: y.ikejiri@ntt.com
Kenji Kumaki
KDDI Corporation
KDDI Bldg. 2-3-2,
Nishishinjuku,
Tokyo 163-8003,
JAPAN
E-mail: ke-kumaki@kddi.com
Peter B. Busschbach
Lucent Technologies
67 Whippany Road
Whippany, NJ, 07981
E-mail: busschbach@lucent.com
Vasile Radoaca
Nortel Networks
Billerica, MA, 01803
PWE3 Working Group Expires September 2007 [Page 26]
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Email: vasile@nortelnetworks.com
14. Intellectual Property Statement
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15. Full Copyright Statement
Copyright (C) The IETF Trust (2007). This document is subject
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This document and the information contained herein are provided on an
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PWE3 Working Group Expires September 2007 [Page 27]
draft-ietf-pwe3-vccv-13 VCCV March 2, 2007
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
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PWE3 Working Group Expires September 2007 [Page 28]
