Signaling Root-Initiated Point-to-Multipoint Pseudowire using LDP
draft-ietf-pwe3-p2mp-pw-03
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Authors | Gianni Vecchio , Lizhong Jin , Luca Martini , Maciek Konstantynowicz , Sami Boutros , Siva Sivabalan , Yuji Kamite | ||
| Last updated | 2011-10-28 (Latest revision 2011-03-02) | ||
| Replaces | draft-martini-pwe3-p2mp-pw | ||
| Replaced by | draft-ietf-pals-p2mp-pw, RFC 8338 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-pwe3-p2mp-pw-03
Network Working Group Siva Sivabalan (Ed.)
Internet Draft Sami Boutros (Ed.)
Intended status: Standards Track Luca Martini
Expires: April 15, 2012 Cisco Systems
Frederic Jounay Maciek Konstantynowicz
Philippe Niger Juniper
France Telecom
Thomas D. Nadeau Gianni Del Vecchio
CA Technologies Swisscom
Simon Delord Yuji Kamite
Telstra NTT Communications
Laurent Ciavaglia Lizhong Jin
Martin Vigoureux ZTE
Alcatel-Lucent
October 27, 2011
Signaling Root-Initiated Point-to-Multipoint Pseudowire using LDP
draft-ietf-pwe3-p2mp-pw-03.txt
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on April 27, 2012.
Boutros Expires April 15, 2012 [Page 1]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
Abstract
This document specifies a mechanism to signal Point-to-Multipoint
(P2MP) Pseudowires (PW) tree using LDP. Such a mechanism is suitable
for any Layer 2 VPN service requiring P2MP connectivity over an IP or
MPLS enabled PSN. A P2MP PW established via the proposed mechanism is
root initiated.
Table of Contents
1. Introduction...................................................2
2. Terminology....................................................4
3. Signaling P2MP PW..............................................5
3.1. PW ingress to egress incompatibility issues...............6
3.2. P2MP PW FEC...............................................7
3.3. Group ID usage...........................................11
3.4. Generic Label TLV........................................11
3.5. Transport LSP TLV........................................12
4. LDP Capability Negotiation....................................13
5. P2MP PW Status................................................15
6. Security Considerations.......................................15
7. IANA Considerations...........................................15
7.1. FEC Type Name Space......................................15
7.2. LDP TLV Type.............................................16
7.3. mLDP Opaque Value Element TLV Type.......................16
7.4. Selective Tree Interface Parameter sub-TLV Type..........16
8. Acknowledgment................................................17
9. References....................................................17
9.1. Normative References.....................................17
9.2. Informative References...................................18
Full Copyright Statement.........................................21
Intellectual Property Statement..................................21
1. Introduction
A Point-to-Multipoint (P2MP) Pseudowire (PW) emulates the
essential attributes of a unidirectional P2MP Telecommunications
service such as P2MP ATM over PSN. A major difference between a
Point-to-Point (P2P) PW outlined in [RFC3985] and a P2MP PW is that
the former is intended for bidirectional service whereas the latter
is intended for both unidirectional and bidirectional services.
Requirements for P2MP PW are described in [P2MP-PW-REQ].
Sivabalan Expires April 27, 2012 [Page 2]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
A P2MP PW can be constructed as either Single Segment (P2MP SS-PW)
or Multi Segment (P2MP MS-PW) Pseudowire as mentioned in [P2MP-PW-
REQ]. P2MP MS-PW is outside the scope of this document. A reference
model for P2MP PW is depicted in Figure 1 below. A transport LSP
associated with a P2MP SS-PW SHOULD be a P2MP MPLS LSP (i.e., P2MP
TE tunnel established via RSVP-TE [RFC4875] or P2MP LSP established
via mLDP [mLDP]) spanning from the Root-PE (R-PE) to the Leaf-PE(s)
(L-PEs) of the P2MP SS-PW tree. For example, in Figure 1, PW1 can be
associated with a P2MP TE tunnel or P2MP LSP setup using [mLDP]
originating from T-PE1 and terminating at T-PE2 and T-PE3.
Mechanisms for establishing P2P SS-PW using LDP are described in
[RFC4447]. In this document, we specify a method to signal P2MP PW
using LDP. In particular, we define new TLVs, parameters, and status
codes to facilitate LDP to signal and maintain P2MP PWs.
|<--------------P2MP PW---------------->|
Native | | Native
Service | |<--PSN1->| |<--PSN2->| | Service
(AC) V V V V V V (AC)
| +-----+ +------+ +------+ |
| | | | P1 |=========|T-PE2 |AC3 | +---+
| | | | .......PW1.........>|-------->|CE3|
| |T-PE1|=========| . |=========| | | +---+
| | .......PW1........ | +------+ |
| | . |=========| . | +------+ |
| | . | | . |=========|T-PE3 |AC4 | +---+
+---+ |AC1 | . | | .......PW1.........>|-------->|CE4|
|CE1|------->|... | | |=========| | | +---+
+---+ | | . | +------+ +------+ |
| | . | +------+ +------+ |
| | . |=========| P2 |=========|T-PE4 |AC5 | +---+
| | .......PW1..............PW1.........>|-------->|CE5|
| | |=========| |=========| | | +---+
| +-----+ +------+ +------+ |
Figure 1: P2MP PW
Sivabalan Expires April 27, 2012 [Page 3]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
As outlined in [P2MP-PW-REQ], even though the traffic flow from an
R-PE to L-PEs is P2MP in nature, it may be desirable for any L-PE to
send unidirectional P2P traffic destined only to the R-PE. The
proposed mechanism takes such option into consideration.
A P2MP PW requires an MPLS LSP to carry the PW traffic, and the MPLS
packets carried over the PW will be encapsulated according to the
methods described in [RFC5332].
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119].
2. Terminology
FEC: Forwarding Equivalence Class
LDP: Label Distribution Protocol
mLDP: Label Distribution Protocol for P2MP LSP
LSP: Label Switching Path
MS-PW: Multi-Segment Pseudowire
P2P: Point to Point
P2MP: Point to Multipoint
PE: Provider Edge
PSN: Packet Switched Network
PW: Pseudowire
SS-PW: Single-Segment Pseudowire
S-PE: Switching Provider Edge Node of MS-PW
Sivabalan Expires April 27, 2012 [Page 4]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
TE: Traffic Engineering
R-PE: Root-PE - ingress PE, PE initiating P2MP PW setup.
L-PE: Leaf-PE - egress PE.
3. Signaling P2MP PW
In order to advertise labels as well as exchange PW related LDP
messages, PEs must establish LDP sessions among themselves using the
Extended Discovery Mechanisms. A PE discovers other PEs that are to
be connected via P2MP PWs either via manual configuration or
autodiscovery [RFC6074].
R-PE and each L-PE MUST be configured with the same FEC as defined
in the following section.
P2MP PW requires that there is an active P2MP transport LSP set up
between R-PE and L-PE(s). The procedure to set up the P2MP transport
LSP is different depending on the protocol used (RSVP-TE or mLDP).
In case of mLDP, an L-PE can decide to join the P2MP LSP at any
time, while in the case of RSVP-TE the P2MP transport LSP is set up
by the R-PE, generally at the initial service provisioning time. It
should be noted that local policy can override any decision to add
or prune existing or new L-PE(s) to/from the tree. In any case, the
PW setup can ignore these differences, and simply assume that the
P2MP transport LSP is available when needed.
A P2MP PW signaling is initiated by the R-PE simply by sending a
P2MP-PW LDP label mapping message to the L-PE(s) belonging to that
P2MP PW. This label mapping message will contain the following:
1. A P2MP Upstream PW FEC element.
2. An Interface Parameters TLV, as described in [RFC4447].
3. A PW Grouping TLV as described in [RFC4447].
4. A Transport LSP TLV.
5. A label TLV for the upstream-assigned label used by R-PE
for the traffic going from R-PE to L-PE(s).
Sivabalan Expires April 27, 2012 [Page 5]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
The R-PE imposes the upstream-assigned label on the outbound packets
sent over the P2MP-PW, and using this label an L-PE identifies the
inbound packets arriving over the P2MP PW.
Additionally, the R-PE MAY send label mapping message(s) to one or
more L-PE(s) to signal unidirectional P2P PW(s). The L-PE(s) can use
such PW(s) to send traffic to the R-PE. This optional label mapping
message will contain the following:
1. P2P Downstream PW FEC element.
2. A label TLV for the down-stream assigned label used by the
corresponding L-PE to send traffic to the R-PE.
The LDP liberal label retention mode is used, and per requirements
specified in [RFC5036], the label request message MUST also be
supported.
The upstream-assigned label is allocated according to the rules in
[RFC5331].
When an L-PE receives a PW Label Mapping Message, it MUST verify
that the associated P2MP transport LSP is in place. If the
associated P2MP transport LSP is not in place, and its type is LDP
P2MP LSP, the L-PE SHOULD attempt to join the P2MP LSP. If the P2MP
transport LSP is not in place, and its type is RSVP-TE P2MP LSP, the
L-PE SHOULD wait till the P2MP transport LSP is signaled.
3.1. PW ingress to egress incompatibility issues
If an R-PE signals a PW with a pw type, CW mode, or interface
parameters that a particular L-PE cannot accept, then the L-PE must
not enable the PW, and notify the user. In this case, a PW status
message of 0x00000001 (Pseudowire Not Forwarding) MUST also be sent
to the R-PE.
Note that this procedure does not apply if the L-PE had not been
provisioned with this particular P2MP PW. In this case according to
the LDP liberal label retention rules, no action is taken.
Sivabalan Expires April 27, 2012 [Page 6]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
3.2. P2MP PW FEC
[RFC4447] specifies two types of LDP FEC elements called "PWid FEC
Element" and "Generalized PWid FEC Element" used to signal P2P PWs.
We define two new types of FEC element called "P2MP Upstream PW FEC
Element" and "P2P Downstream PW FEC Element". These FEC elements are
associated with a mandatory upstream assigned label and an optional
downstream assigned label respectively.
FEC type of the P2MP Upstream PW FEC Element is 0x82 (pending IANA
allocation) and is encoded 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|FEC Type = 0x82|C| PW Type | PW Info Length|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AGI Type | Length | AGI Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ AGI Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AII Type | Length | SAII Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ SAII Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Transport LSP TLV (0x0971)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |PMSI Tunnel Typ| Transport LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Transport LSP ID (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Optional Parameters |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: P2MP Upstream PW FEC Element
Sivabalan Expires April 27, 2012 [Page 7]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
* PW Type:
15-bit representation of PW type, and the assigned values are
assigned by IANA.
* C bit:
A value of 1 or 0 indicates whether control word is present or
absent for the P2MP PW.
* PW Info Length:
Sum of the lengths of AGI, SAII and Optional Parameters field in
octets. If this value is 0, then it references all PWs using the
specified grouping ID. In this case, there are neither other FEC
element fields (AGI, SAII, etc.) present, nor any interface
parameters TLVs.
* AGI:
Attachment Group Identifier can be used to uniquely identify VPN
or VPLS instance associated with the P2MP PW. This has the same
format as the Generalized PWid FEC element [RFC4447].
* SAII:
Source Attachment Individual Identifier is used to identify the
root of the P2MP PW. The root is represented using AII type 2
format specified in [RFC5003]. Note that the SAII can be omitted
by simply setting the length and type to zero.
P2MP PW is identified by the Source Attachment Identifier (SAI).
If the AGI is non-null, the SAI is the combination of the SAII
and the AGI, if the AGI is null, the SAI is the SAII.
* Transport LSP TLV:
A P2MP PW MUST be associated with a transport LSP. The Transport
LSP TLV contains the information required to identify the
transport LSP. Transport LSP TLV MUST immediately follow the FEC,
Sivabalan Expires April 27, 2012 [Page 8]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
but is not part of the FEC, and SHOULD NOT be used in other
messages where the FEC is used.
* Optional Parameters:
The Optional Parameter field can contain some TLVs that are not
part of the FEC, but are necessary for the operation of the PW.
This proposed mechanism uses two such TVLs: Interface Parameters
TLV and Group ID TLV.
The Interface Parameters TLV and Group ID TLV specified in
[RFC4447] can also be used in conjunction with P2MP PW FEC. For
Group ID TLV the sender and receiver of these TLVs should follow
the same rules and procedures specified in [RFC4447]. For
Interface Parameters TLV the procedure differs from the one
specified in [RFC4447] due to specifics of P2MP connectivity. When
the interface parameters are signaled by an R-PE, each L-PE must
check if its configured value(s) is less than or equal to the
threshold value provided by the R-PE (e.g., MTU size (Ethernet),
max number of concatenated ATM cells, etc)). For other interface
parameters like CEP/TDM Payload bytes (TDM), the value MUST
exactly match the values signaled by the R-PE.
Multicast traffic stream associated with a P2MP PW can be
selective or inclusive. To support the former, this document
defines a new optional Selective Tree Interface Parameter sub-TLV
(type is pending IANA allocation) according to the format
described in [RFC4447]. The value of the sub-TLV contains the
source and the group for a given multicast tree as shown in Figure
3. This is similar to the way (S, G) is defined in [VPLS-MCAST].
Also, if a P2MP PW is associated with multiple selective trees,
the corresponding label mapping message will carry more than one
instances of this Sub-TLV. Furthermore, in the absence of this
sub-TLV, the P2MP PW is associated with all multicast traffic
stream originating from the root.
Sivabalan Expires April 27, 2012 [Page 9]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
+----------------------------------------- +
| Multicast Source Length (1 Octet) |
+----------------------------------------- +
| Multicast Source (variable length) |
+----------------------------------------- +
| Multicast Group Length (1 Octet) |
+----------------------------------------- +
| Multicast Group (variable length) |
+----------------------------------------- +
Figure 3: Selective Tree Interface Parameter Sub-TLV Value
The Multicast Source field contains the address of the multicast
source. The Multicast Source field contains an IPv4 address or IPv6
address depending on whether the Multicast Source Length is 32 or
128. The Multicast Source Length can be set to 0 to indicate
wildcard.
The Multicast Group field contains the address of the multicast
group. The Multicast Group field contains an IPv4 address or IPv6
address depending on whether the Multicast Group Length is 32 or
128. The Multicast Group Length can be set to 0 to indicate
wildcard.
Note that since the LDP label mapping message is only sent by an R-
PE to all the L-PEs, it is not possible to negotiate any interface
parameters.
The type of optional P2P Downstream PW FEC Element is 0x83 (pending
IANA allocation), and is encoded as follows:
Sivabalan Expires April 27, 2012 [Page 10]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|FEC Type = 0x83|C| PW Type | PW Info Length|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AGI Type | Length | AGI Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ AGI Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AII Type | Length | SAII Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ SAII Value (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: P2P Downstream PW FEC Element
The definition of the fields in the P2P Downstream PW FEC Element is
the same as those of P2MP Upstream PW FEC Element.
3.3. Group ID usage
The Grouping TLV as defined in [RFC4447] contains a group ID capable
of indicating an arbitrary group membership of a P2MP-PW. This group
ID can be used in LDP "wild card" status, and withdraw label
messages, as described in [RFC4447].
3.4. Generic Label TLV
As in the case of P2P PW signaling, P2MP PW labels are carried
within Generic Label TLV contained in LDP Label Mapping Message. A
Generic Label TLV is formatted and processed as per the rules and
procedures specified in [RFC4447]. For a given P2MP PW, a single
upstream-assigned label is allocated by the R-PE, and is advertised
to all the L-PEs using the Generic Label TLV in label mapping
message containing the P2MP Upstream PW FEC element.
Sivabalan Expires April 27, 2012 [Page 11]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
The R-PE MAY also allocate a unique label for each L-PE from which
it intends to receive P2P traffic. Such a label is advertised to the
L-PE using Generic Label TLV in label mapping message.
3.5. Transport LSP TLV
A P2MP PW MUST be associated with a transport LSP which can be
established using RSVP-TE or mLDP. Thus, a Label Mapping Message
MUST contain the identity of the transport LSP. For this purpose,
this specification introduces a new TLV called "Transport LSP TLV"
which 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Transport LSP TLV (0x0971)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |PMSI Tunnel Typ| Tunnel Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Tunnel Identifier (contd.) ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Transport LSP TLV
Note: TLV number pending IANA allocation.
* Reserved Flags:
Reserved bits Must be set to 0 when transmitting the message, and
ignored on receiving the message.
* PMSI Tunnel Type:
The Transport LSP Type identifies the type of technology used to
establish a transport LSP. The PMSI tunnel type is defined in
[L3VPN-MCAST].
Sivabalan Expires April 27, 2012 [Page 12]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
When the type is set to mLDP P2MP LSP, the Tunnel Identifier is
a P2MP FEC Element as defined in [mLDP]. A new mLDP Opaque Value
Element type for L2VPN-MCAST application needs to be allocated.
Editor Comment: The content of the Opaque Value Element TLV is a
TBD.
* Tunnel Identifier:
The Tunnel containing the Transport LSP is identified by the
Tunnel Identifier which is defined in [L3VPN-MCAST].
Transport LSP TLV MUST be present only in the Label Mapping
Message. An R-PE sends Label Mapping Message as soon as the
transport LSP ID associated with the P2MP PW is known (e.g., via
configuration) regardless of the operational state of that
transport LSP. Similarly, an R-PE does not withdraw the labels
when the corresponding transport LSP goes down. Furthermore, an
L-PE retains the P2MP PW labels regardless of the operational
status of the transport LSP.
Note that a given transport LSP can be associated with more than one
P2MP PWs and all P2MP PWs will be sharing the same R-PE and L-PE(s).
In the case of LDP P2MP LSP, when an L-PE receives the Label
Mapping Message, it can initiate the process of joining the P2MP LSP
tree associated with the P2MP PW.
In the case of RSVP-TE P2MP LSP, only the R-PE initiates the
signaling of P2MP LSP.
4. LDP Capability Negotiation
The capability of supporting P2MP PW must be advertised to all LDP
peers. This is achieved by using the methods in [RFC5561] and
advertising the P2MP PW LDP capability TLV. If an LDP peer supports
the dynamic capability advertisement, this can be done by sending a
new capability message with the S bit set for the P2MP PW capability
TLV. If the peer does not support dynamic capability advertisement,
then the P2MP PW TLV MUST be included in the LDP initialization
Sivabalan Expires April 27, 2012 [Page 13]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
procedures in the capability parameter [RFC5561]. An LSR having P2MP
PW capability MUST recognize both P2MP Upstream FEC Element and P2P
Downstream FEC Element in LDP Label Binding Message.
In line with requirements listed in [RFC5561] the following TLV is
defined to indicate the P2MP PW capability:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| TLV Code Point=0x703 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| Reserved | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: P2MP PW LDP Capability TLV
Note: TLV number pending IANA allocation.
* U-bit:
SHOULD be 1 (ignore if not understood).
* F-bit:
SHOULD be 0 (don't forward if not understood).
* TLV Code Point:
The TLV type identifies a specific capability. The P2MP PW
capability code point is requested in the IANA allocation section
below.
* S-bit:
The State Bit indicates whether the sender is advertising or
withdrawing the P2MP PW capability. The State bit is used as
follows:
1 - The TLV is advertising the capability specified by the
TLV Code Point.
Sivabalan Expires April 27, 2012 [Page 14]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
0 - The TLV is withdrawing the capability specified by the
TLV Code Point.
5. P2MP PW Status
In order to support the proposed mechanism, a node MUST be capable
of handling PW status. As such, PW status negotiation procedure
described in [RFC4447] is not applicable to P2MP PW.
Once an L-PE successfully processes a Label Mapping Message for a
P2MP PW, it MUST send appropriate PW status according to the
procedure specified [RFC4447] to notify the PW status. If there is
no PW status notification required, then no PW status notification
is sent (for example if the P2MP PW is established and operational
with a status of 0x00000000, pw status message is not necessary). PW
status message sent from any L-PE to R-PE contains P2P Downstream PW
FEC to identify the PW.
An R-PE also sends PW status to L-PE(s) to reflect its view of a
P2MP PW state. Such PW status message contains P2MP Upstream PW FEC
to identify the PW.
Connectivity status of the underlying P2MP LSP that P2MP PW is
associated with, can be verified using LSP Ping and Traceroute
procedures described in [P2MP-LSP-PING].
6. Security Considerations
The security measures described in [RFC4447] is adequate for the
proposed mechanism.
7. IANA Considerations
7.1. FEC Type Name Space
This document uses two new FEC element types, number 0x82 and 0x83
will be requested as an allocation from the registry "FEC Type Name
Space" for the Label Distribution Protocol (RFC5036):
Sivabalan Expires April 27, 2012 [Page 15]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
Value Hex Name Reference
------- ----- ----------------------------- ---------
130 0x82 P2MP PW Upstream FEC Element RFCxxxx
131 0x83 P2MP PW Downstream FEC Element RFCxxxx
7.2. LDP TLV Type
This document uses a new LDP TLV types, IANA already maintains a
registry of name "TLV TYPE NAME SPACE" defined by RFC5036. The
following values are suggested for assignment:
TLV type Description:
0x0971 Transport LSP TLV
0x0703 P2MP PW Capability TLV
7.3. mLDP Opaque Value Element TLV Type
This document requires allocation of a new mLDP Opaque Value Element
Type from the LDP MP Opaque Value Element type name space defined in
[mLDP].
The following value is suggested for assignment:
TLV type Description
0x3 L2VPN-MCAST application TLV
7.4. Selective Tree Interface Parameter sub-TLV Type
This document requires allocation of a sub-TLV from the registry
"Pseudowire Interface Parameters Sub-TLV Type".
The following value is suggested for assignment:
TLV type Description
0x0D Selective Tree Interface Parameter.
Sivabalan Expires April 27, 2012 [Page 16]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
8. Acknowledgment
Authors would like thank Kamran Raza, Andre Pelletier, and Parag
Jain for their valuable suggestions.
9. References
9.1. Normative References
[RFC2119] Bradner. S, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March, 1997.
[RFC4447] "Transport of Layer 2 Frames Over MPLS", Martini, L.,
et al., rfc4447 April 2006.
[RFC5036] Andersson, L., Minei, I., and B. Thomas, "LDP
Specification", RFC 5036, October 2007.
[RFC5003] C. Metz, L. Martini, F. Balus, J. Sugimoto, "Attachment
Individual Identifier (AII) Types for Aggregation", RFC5003,
September 2007.
[RFC5331] R. Aggarwal, Y. Rekhter, E. Rosen, "MPLS Upstream Label
Assignment and Context-Specific Label Space", rfc5331, August 2008.
[RFC5332] T. Eckert, E. Rosen, Ed.,R. Aggarwal, Y. Rekhter, "MPLS
Multicast Encapsulations", rfc5332, August 2008.
[mLDP] I. Minei, K. Kompella, I. Wijnands, B. Thomas, "Label
Distribution Protocol Extensions for Point-to-Multipoint and
Multipoint-to-Multipoint Label Switched Paths", draft-ietf-mpls-ldp-
p2mp-06, Work In Progress, April 2009.
[RFC4875] R. Aggarwal, Ed., D. Papadimitriou, Ed., S. Yasukawa, Ed.,
"Extensions to Resource Reservation Protocol - Traffic Engineering
(RSVP-TE) for Point-to-Multipoint TE Label Switched Paths (LSPs).",
rfc4875, May 2007.
Sivabalan Expires April 27, 2012 [Page 17]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
[L3VPN-MCAST] R. Aggarwal, E. Rosen, T. Morin, Y. Rekhter, "BGP
Encodings and Procedures for Multicast in MPLS/BGP IP VPNs", draft-
ietf-l3vpn-2547bis-mcast-bgp-08.txt, Work in Progress, October 2009.
[RFC5561] B.Thomas, K.Raza, S.Aggarwal, R.Agarwal, JL. Le Roux, "LDP
Capabilities", rfc5561, July 2009.
9.2. Informative References
[RFC3985] Stewart Bryant, et al., "PWE3 Architecture", RFC3985
[RFC6074] E. Rosen,W. Luo,B. Davie,V. Radoaca "Provisioning, Auto-
Discovery, and Signaling in Layer 2 Virtual Private Networks
(L2VPNs)", RFC6074, January 2011.
[P2MP-PW-REQ] F. Jounay, et. al, "Requirements for Point to
Multipoint Pseudowire", draft-ietf-pwe3-p2mp-pw-requirements-03.txt,
Work in Progress, August 2010.
[P2MP-LSP-PING] A. Farrel, S. Yasukawa, "Detecting Data Plane
Failures in Point-to-Multipoint Multiprotocol Label Switching (MPLS)
- Extensions to LSP Ping", draft-ietf-mpls-p2mp-lsp-ping-15.txt,
Work In Progress, January 2011.
[VPLS-MCAST] R. Aggarwal, Y. Kamite, L. Fang, and Y. Rekhter,
"Multicast in VPLS", draft-ietf-l2vpn-vpls-mcast-09.txt, Work In
Progress, July 2011.
Author's Addresses
Siva Sivabalan
Cisco Systems, Inc.
2000 Innovation Drive
Kanata, Ontario, K2K 3E8
Canada
Email: msiva@cisco.com
Sami Boutros
Sivabalan Expires April 27, 2012 [Page 18]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
Cisco Systems, Inc.
3750 Cisco Way
San Jose, California 95134
USA
Email: sboutros@cisco.com
Luca Martini
Cisco Systems, Inc.
9155 East Nichols Avenue, Suite 400
Englewood, CO, 80112
United States
Email: lmartini@cisco.com
Maciek Konstantynowicz
Juniper Networks
UNITED KINGDOM
Email: maciek@juniper.net
Gianni Del Vecchio
Swisscom (Schweiz) AG
Zentweg 9
CH-3006 Bern
Switzerland
Email: Gianni.DelVecchio@swisscom.com
Thomas D. Nadeau
CA Technologies
273 Corporate Drive
Portsmouth, NH 03801
USA
Email: thomas.nadeau@ca.com
Frederic Jounay
France Telecom
2, avenue Pierre-Marzin
22307 Lannion Cedex
FRANCE
Email: frederic.jounay@orange-ftgroup.com
Philippe Niger
France Telecom
2, avenue Pierre-Marzin
Sivabalan Expires April 27, 2012 [Page 19]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
22307 Lannion Cedex
FRANCE
Email: philippe.niger@orange-ftgroup.com
Yuji Kamite
NTT Communications Corporation
Tokyo Opera City Tower
3-20-2 Nishi Shinjuku, Shinjuku-ku
Tokyo 163-1421
Japan
Email: y.kamite@ntt.com
Lizhong Jin
ZTE
889 Bibo Road,
Shanghai, 201203
P.R.China
Email: lizhong.jin@zte.com.cn
Martin Vigoureux
Alcatel-Lucent
Route de Villejust
Nozay, 91620
France
Email: martin.vigoureux@alcatel-lucent.com
Laurent Ciavaglia
Alcatel-Lucent
Route de Villejust
Nozay, 91620
France
Email: Laurent.Ciavaglia@alcatel-lucent.com
Simon Delord
Telstra
E-mail: simon.a.delord@team.telstra.com
Sivabalan Expires April 27, 2012 [Page 20]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
Full Copyright Statement
Copyright (c) 2010 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.
All IETF Documents and the information contained therein are provided
on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE
ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights.
Copies of Intellectual Property disclosures made to the IETF
Secretariat and any assurances of licenses to be made available, or
the result of an attempt made to obtain a general license or
permission for the use of such proprietary rights by implementers or
users of this specification can be obtained from the IETF on-line IPR
repository at http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
any standard or specification contained in an IETF Document. Please
address the information to the IETF at ietf-ipr@ietf.org.
Sivabalan Expires April 27, 2012 [Page 21]
Internet-Draft draft-ietf-pwe3-p2mp-pw-03.txt October 2011
The definitive version of an IETF Document is that published by, or
under the auspices of, the IETF. Versions of IETF Documents that are
published by third parties, including those that are translated into
other languages, should not be considered to be definitive versions
of IETF Documents. The definitive version of these Legal Provisions
is that published by, or under the auspices of, the IETF. Versions of
these Legal Provisions that are published by third parties, including
those that are translated into other languages, should not be
considered to be definitive versions of these Legal Provisions.
For the avoidance of doubt, each Contributor to the UETF Standards
Process licenses each Contribution that he or she makes as part of
the IETF Standards Process to the IETF Trust pursuant to the
provisions of RFC 5378. No language to the contrary, or terms,
conditions or rights that differ from or are inconsistent with the
rights and licenses granted under RFC 5378, shall have any effect and
shall be null and void, whether published or posted by such
Contributor, or included with or in such Contribution.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Sivabalan Expires April 27, 2012 [Page 22]