draft-ietf-bier-mvpn-03.txt   draft-ietf-bier-mvpn-04.txt 
Internet Engineering Task Force E. Rosen, Ed. Internet Engineering Task Force E. Rosen, Ed.
Internet-Draft Juniper Networks, Inc. Internet-Draft Juniper Networks, Inc.
Intended status: Standards Track M. Sivakumar Intended status: Standards Track M. Sivakumar
Expires: December 22, 2016 Cisco Systems, Inc. Expires: January 19, 2017 Cisco Systems, Inc.
S. Aldrin S. Aldrin
Google, Inc. Google, Inc.
A. Dolganow A. Dolganow
Alcatel-Lucent Nokia
T. Przygienda T. Przygienda
Ericsson Juniper Networks, Inc.
June 20, 2016 July 18, 2016
Multicast VPN Using BIER Multicast VPN Using BIER
draft-ietf-bier-mvpn-03 draft-ietf-bier-mvpn-04
Abstract Abstract
The Multicast Virtual Private Network (MVPN) specifications require The Multicast Virtual Private Network (MVPN) specifications require
the use of multicast tunnels ("P-tunnels") that traverse a Service the use of multicast tunnels ("P-tunnels") that traverse a Service
Provider's backbone network. The P-tunnels are used for carrying Provider's backbone network. The P-tunnels are used for carrying
multicast traffic across the backbone. A variety of P-tunnel types multicast traffic across the backbone. A variety of P-tunnel types
are supported. Bit Index Explicit Replication (BIER) is a new are supported. Bit Index Explicit Replication (BIER) is a new
architecture that provides optimal multicast forwarding through a architecture that provides optimal multicast forwarding through a
"multicast domain", without requiring intermediate routers to "multicast domain", without requiring intermediate routers to
skipping to change at page 1, line 47 skipping to change at page 1, line 47
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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."
This Internet-Draft will expire on December 22, 2016. This Internet-Draft will expire on January 19, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Use of the PMSI Tunnel Attribute . . . . . . . . . . . . . . 4 2. Use of the PMSI Tunnel Attribute . . . . . . . . . . . . . . 4
3. Explicit Tracking . . . . . . . . . . . . . . . . . . . . . . 6 2.1. MPLS Label . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Using the LIR Flag . . . . . . . . . . . . . . . . . . . 7 2.2. Explicit Tracking . . . . . . . . . . . . . . . . . . . . 7
3.2. Using the LIR-pF Flag . . . . . . . . . . . . . . . . . . 7 2.2.1. Using the LIR Flag . . . . . . . . . . . . . . . . . 7
4. Data Plane . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.2. Using the LIR-pF Flag . . . . . . . . . . . . . . . . 7
4.1. Encapsulation and Transmission . . . . . . . . . . . . . 8 3. Data Plane . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Disposition . . . . . . . . . . . . . . . . . . . . . . . 9 3.1. Encapsulation and Transmission . . . . . . . . . . . . . 8
4.2.1. At a BFER that is an Egress PE . . . . . . . . . . . 9 3.2. Disposition . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.2. At a BFER that is a P-tunnel Segmentation Boundary . 9 3.2.1. At a BFER that is an Egress PE . . . . . . . . . . . 10
5. Contributor Addresses . . . . . . . . . . . . . . . . . . . . 10 3.2.2. At a BFER that is a P-tunnel Segmentation Boundary . 10
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 4. Contributor Addresses . . . . . . . . . . . . . . . . . . . . 10
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9.1. Normative References . . . . . . . . . . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.2. Informative References . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction 1. Introduction
[RFC6513] and [RFC6514] specify the protocols and procedures that a [RFC6513] and [RFC6514] specify the protocols and procedures that a
Service Provider (SP) can use to provide Multicast Virtual Private Service Provider (SP) can use to provide Multicast Virtual Private
Network (MVPN) service to its customers. Multicast tunnels are Network (MVPN) service to its customers. Multicast tunnels are
created through an SP's backbone network; these are known as created through an SP's backbone network; these are known as
"P-tunnels". The P-tunnels are used for carrying multicast traffic "P-tunnels". The P-tunnels are used for carrying multicast traffic
across the backbone. The MVPN specifications allow the use of across the backbone. The MVPN specifications allow the use of
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originator of the route that is carrying this PTA. This will originator of the route that is carrying this PTA. This will
either be a /32 IPv4 address or a /128 IPv6 address. Whether either be a /32 IPv4 address or a /128 IPv6 address. Whether
the address is IPv4 or IPv6 can be inferred from the total the address is IPv4 or IPv6 can be inferred from the total
length of the PMSI Tunnel attribute. length of the PMSI Tunnel attribute.
o "MPLS label". This field contains an upstream-assigned MPLS o "MPLS label". This field contains an upstream-assigned MPLS
label. It is assigned by the router that originates the BGP route label. It is assigned by the router that originates the BGP route
to which the PTA is attached. Constraints on the way in which the to which the PTA is attached. Constraints on the way in which the
originating router selects this label are discussed below. originating router selects this label are discussed below.
o "Flags". When the tunnel type is BIER, two of the bits in the PTA o "Flags". When the tunnel type is BIER, two of the flags in the
Flags field are meaningful. Details about the use of these bits PTA Flags field are meaningful. Details about the use of these
can be found in Section 3. flags can be found in Section 2.2.
* "Leaf Info Required per Flow (LIR-pF)". This bit is introduced
in [EXPLICIT_TRACKING]. A BFIR SHOULD NOT set this bit UNLESS
it knows that all the BFERs in the BIER domain (or at least all
the BFERs to which it needs to transmit) support this bit.
(How this is known is outside the scope of this document.)
This bit MAY be set in a (C-*,C-*) S-PMSI A-D route, but MUST
NOT be set in I-PMSI A-D routes or in other S-PMSI A-D routes.
* "Leaf Info Required Bit". The setting of this bit depends upon
the type of route and the NLRI of the route that carries the
PTA.
+ In an I-PMSI A-D route or a (C-*,C-*) S-PMSI A-D route, the * "Leaf Info Required per Flow (LIR-pF)". This flag is
bit SHOULD be clear, unless the LIR-pF bit has also been set introduced in [EXPLICIT_TRACKING]. A BFIR SHOULD NOT set this
(see above). This bit SHOULD also be clear in a (C-S,C-*) flag UNLESS it knows that all the BFERs in the BIER domain (or
or (C-*,C-G) S-PMSI A-D route. at least all the BFERs to which it needs to transmit) support
this flag. (How this is known is outside the scope of this
document.) Procedures for the use of this flag are given in
Section 2.2.2
+ In other S-PMSI A-D routes, the bit SHOULD be set. * "Leaf Info Required Bit". See Section 2.2.1.
Note that if a PTA specifying "BIER" is attached to an I-PMSI or Note that if a PTA specifying "BIER" is attached to an I-PMSI or
S-PMSI A-D route, the route MUST NOT be distributed beyond the S-PMSI A-D route, the route MUST NOT be distributed beyond the
boundaries of a BIER domain. That is, any routers that receive the boundaries of a BIER domain. That is, any routers that receive the
route must be in the same BIER domain as the originator of the route. route must be in the same BIER domain as the originator of the route.
If the originator is in more than one BIER domain, the route must be If the originator is in more than one BIER domain, the route must be
distributed only within the BIER domain in which the BFR-Prefix in distributed only within the BIER domain in which the BFR-Prefix in
the PTA uniquely identifies the originator. As with all MVPN routes, the PTA uniquely identifies the originator. As with all MVPN routes,
distribution of these routes is controlled by the provisioning of distribution of these routes is controlled by the provisioning of
Route Targets. Route Targets.
2.1. MPLS Label
Suppose an ingress PE originates two x-PMSI A-D routes, where we use Suppose an ingress PE originates two x-PMSI A-D routes, where we use
the term "x-PMSI" to mean "I-PMSI or S-PMSI". Suppose both routes the term "x-PMSI" to mean "I-PMSI or S-PMSI". Suppose both routes
carry a PTA, and the PTA of each route specifies"BIER". carry a PTA, and the PTA of each route specifies"BIER".
o If the two routes do not carry the same set of Route Targets o If the two routes do not carry the same set of Route Targets
(RTs), then their respective PTAs MUST contain different MPLS (RTs), then their respective PTAs MUST contain different MPLS
label values. label values.
o If the ingress PE is supporting MVPN extranet ([EXTRANET]) o If the ingress PE is supporting MVPN extranet ([RFC7900])
functionality, and if the two routes originate from different functionality, and if the two routes originate from different
VRFs, then the respective PTAs of the two routes MUST contain VRFs, then the respective PTAs of the two routes MUST contain
different MPLS label values. different MPLS label values.
o If the ingress PE is supporting the "Extranet Separation" feature o If the ingress PE is supporting the "Extranet Separation" feature
of MVPN extranet (see Section 7.3 of [EXTRANET], section ), and if of MVPN extranet (see Section 7.3 of [RFC7900], section ), and if
one of the routes carries the "Extranet Separation" extended one of the routes carries the "Extranet Separation" extended
community and the other does not, then the respective PTAs of the community and the other does not, then the respective PTAs of the
two routes MUST contain different MPLS label values. two routes MUST contain different MPLS label values.
o If segmented P-tunnels are being used, then the respective PTAs of o If segmented P-tunnels are being used, then the respective PTAs of
the two routes MUST contain different MPLS label values, as long the two routes MUST contain different MPLS label values, as long
as the NLRIs are not identical. In this case, the MPLS label can as the NLRIs are not identical. In this case, the MPLS label can
be used by the BFER to identify the particular C-flow to which a be used by the BFER to identify the particular C-flow to which a
data packet belongs, and this greatly simplifies the process of data packet belongs, and this greatly simplifies the process of
forwarding a received packet to its next P-tunnel segment. This forwarding a received packet to its next P-tunnel segment. This
is explained further in Section 4. is explained further below. See also Section 3.
When segmented P-tunnels are being used, an ABR or ASBR may receive, When segmented P-tunnels are being used, an ABR or ASBR may receive,
from a BIER domain, an x-PMSI A-D route whose PTA specifies "BIER". from a BIER domain, an x-PMSI A-D route whose PTA specifies "BIER".
This means that BIER is being used for one segment of a segmented This means that BIER is being used for one segment of a segmented
P-tunnel. The ABR/ASBR may in turn need to originate an x-PMSI A-D P-tunnel. The ABR/ASBR may in turn need to originate an x-PMSI A-D
route whose PTA identifies the next segment of the P-tunnel. The route whose PTA identifies the next segment of the P-tunnel. The
next segment may also be "BIER". Suppose an ASBR receives x-PMSI A-D next segment may also be "BIER". Suppose an ASBR receives x-PMSI A-D
routes R1 and R2, and as a result originates x-PMSI A-D routes R3 and routes R1 and R2, and as a result originates x-PMSI A-D routes R3 and
R4 respectively, where the PTAs of each of the four routes specify a R4 respectively, where the PTAs of each of the four routes specify
BIER. Then the PTAs of R3 and R4 MUST NOT specify the same MPLS BIER. Then the PTAs of R3 and R4 MUST NOT specify the same MPLS
label, UNLESS both of the following conditions hold: label, UNLESS both of the following conditions hold:
o R1 and R2 have the same "originating router" in their respective o R1 and R2 have the same "originating router" in their respective
NLRIs. NLRIs.
o R1 and R2 specify the same MPLS label in their respective PTAs. o R1 and R2 specify the same MPLS label in their respective PTAs.
3. Explicit Tracking The ABR/ASBR MUST then program its dataplane such that a packet
arriving with the upstream-assigned label specified in route R1 is
transmitted with the upstream-assigned label specified in route R3,
and a packet arriving with the upstream-assigned label specified in
route R2 is transmitted with the label specified in route R4. Of
course, the data plane must also be programmed to encapsulate the
transmitted packets with an appropriate BIER header, whose BitString
is determined by the multicast flow overlay.
2.2. Explicit Tracking
When using BIER to transport an MVPN data packet through a BIER When using BIER to transport an MVPN data packet through a BIER
domain, an ingress PE functions as a BFIR (see [BIER_ARCH]). The domain, an ingress PE functions as a BFIR (see [BIER_ARCH]). The
BFIR must determine the set of BFERs to which the packet needs to be BFIR must determine the set of BFERs to which the packet needs to be
delivered. This can be done in either of two ways: delivered. This can be done in either of two ways:
1. By using the explicit tracking mechanism based on the "Leaf Info 1. Using the explicit tracking mechanism based on the "Leaf Info
Required" flag, as specified in [RFC6513] and [RFC6514], or Required" flag specified in [RFC6513] and [RFC6514]. This method
is further described in Section 2.2.1.
2. By using the explicit tracking mechanism based on the LIR-pF flag 2. Using the explicit tracking mechanism based on the LIR-pF flag
as specified in [EXPLICIT_TRACKING]. This mechanism MAY be used specified in [EXPLICIT_TRACKING]. This method, further described
if (and only if) segmented P-tunnels are not being used. in Section 2.2.2, may be used if (and only if) segmented
P-tunnels are not being used.
3.1. Using the LIR Flag 2.2.1. Using the LIR Flag
To determine the set of BFERs to which a given MVPN data packet needs To determine the set of BFERs to which the packets of a given C-flow
to be delivered, the BFIR originating an S-PMSI A-D route sets the must be sent, a BFIR MUST originate a (C-S,C-G) S-PMSI A-D route for
LIR bit in the route's PTA. Per [RFC6514], the BFERs will respond the given C-flow. It MUST attach a PTA to that route, and MUST set
with Leaf A-D routes. By matching the received Leaf A-D routes to the LIR flag in the PTA. Per [RFC6514], the BFERs that need to
the originated S-PMSI A-D routes, the originator of the S-PMSI A-D receive that C-flow will respond with (C-S,C-G) Leaf A-D routes. By
route determines the set of BFERs that need to receive the multicast matching the received Leaf A-D routes to the originated S-PMSI A-D
data flow (or flows) that is (are) identified in the NLRI of the of routes, the originator of the S-PMSI A-D route determines the set of
the S-PMSI A-D route. BFERs that need to receive the multicast data flow that is identified
in the NLRI of S-PMSI A-D route.
This requires that each BFIR originate an S-PMSI A-D route for each The PTA MAY specify a tunnel type ("BIER") and a non-zero MPLS label.
C-flow for which it serves as BFIR. The BFIR MAY include, in each (If it specifies one of these it MUST also specify the other.)
such route, a PTA as described in Section 2. However, if the BFIR Alternatively, the PTA MAY specify "no tunnel type" and a zero MPLS
has originated an I-PMSI A-D route or a wildcard S-PMSI A-D route label. In this case, the tunnel type ("BIER") and non-zero MPLS
that "matches" (according to the rules of [RFC6625]) a particular label MUST be specified in an I-PMSI A-D route or in a wildcard
C-flow, then it may do explicit tracking for that C-flow by S-PMSI A-D route that "matches" (according to the rules of [RFC6625])
originating an S-PMSI A-D route for that C-flow, but including a PTA the C-flow in question.
that specifies "no tunnel type".
3.2. Using the LIR-pF Flag 2.2.2. Using the LIR-pF Flag
If segmented P-tunnels are not being used, the BFIR can determine the If segmented P-tunnels are not being used, the BFIR can determine the
set of BFERs to which a given MVPN data packet needs to be delivered set of BFERs that need to receive the packets of a given (C-S,C-G)
by originating a (C-*,C-*) S-PMSI A-D route, and by setting the LIR- C-flow as follows. The BFIR MUST originate a wildcard S-PMSI A-D
pF flag in the PTA of that route. Per [EXPLICIT_TRACKING], each BFER route (either (C-*,C-*), (C-*,C-G), or (C-S,C-G) and the PTA of that
will respond with one or more Leaf A-D routes, identifying the flows route MUST the following settings:
that it is expecting to receive from the BFIR that originated the
(C-*,C-*) S-PMSI A-D route. o The LIR-pF flag MUST be set;
o The tunnel type MUST be set to "BIER;
o A non-zero MPLS label MUST be specified.
Per [EXPLICIT_TRACKING], a BFER that needs to receive (C-S,C-G)
traffic from the BFIR will respond with a Leaf A-D route.
A BFIR MUST NOT use this method of finding the set of BFERs needing A BFIR MUST NOT use this method of finding the set of BFERs needing
to receive a given C-flow unless it knows that all those BFERs to receive a given C-flow unless it knows that all those BFERs
support the LIR-pF flag. How this is known is outside the scope of support the LIR-pF flag. How this is known is outside the scope of
this document. this document.
This option greatly reduces the number of S-PMSI A-D routes that a This method greatly reduces the number of S-PMSI A-D routes that a
BFIR needs to originate; it now needs to originate only one such BFIR needs to originate; it can now originate as few as one such
route, rather than one for each C-flow. However, it does not provide route (a (C-*,C-*) S-PMSI A-D route), rather than one for each
a way for the BFIR to assign a distinct label to each C-flow. C-flow. However, the method does not provide a way for the BFIR to
Therefore it cannot be used when segmented P-tunnels are in use (see assign a distinct label to each C-flow. Therefore it cannot be used
Section 4 for an explanation). when segmented P-tunnels are in use (see Section 3 for an
explanation).
4. Data Plane Note: if a BFIR originates a (C-*,C-*) S-PMSI A-D route with the LIR-
pF flag set, but also originates a more specific wildcard route that
matches a particular (C-S,C-G), the BFERs will not originate Leaf A-D
routes for that (C-S,C-G) unless the LIR-pF flag is also set in the
more specific wildcard route. If the BFIR also originates a
(C-S,C-G) S-PMSI A-D route without the LIR flag set, the BFERs will
not originate Leaf A-D routes for that (C-S,C-G) unless the LIR flag
is also set in that route.
The MVPN application plays the role of the "multicast flow layer" as 3. Data Plane
described in [BIER_ARCH].
4.1. Encapsulation and Transmission The MVPN application plays the role of the "multicast flow overlay"
as described in [BIER_ARCH].
3.1. Encapsulation and Transmission
To transmit an MVPN data packet, an ingress PE follows the rules of To transmit an MVPN data packet, an ingress PE follows the rules of
[RFC6625] to find the S-PMSI A-D route or I-PMSI A-D route that is a [RFC6625] to find the S-PMSI A-D route or I-PMSI A-D route that is a
"match for transmission" for that packet. (In applying the rules of "match for transmission" for that packet. (In applying the rules of
[RFC6625], any S-PMSI A-D route with a PTA specifying "no tunnel [RFC6625], any S-PMSI A-D route with a PTA specifying "no tunnel
information" is ignored.) If the matching route has a PTA specifying information" is ignored.) If the matching route has a PTA specifying
a "BIER", the (upstream-assigned) MPLS label from that PTA is pushed "BIER", the (upstream-assigned) MPLS label from that PTA is pushed on
on the packet's label stack. Then the packet is encapsulated in a the packet's label stack. Then the packet is encapsulated in a BIER
BIER header and forwarded, according to the procedures of [BIER_ARCH] header and forwarded, according to the procedures of [BIER_ARCH] and
and [BIER_ENCAPS]. (See especially Section 4, "Imposing and [BIER_ENCAPS]. (See especially Section 4, "Imposing and Processing
Processing the BIER Encapsulation", of [BIER_ENCAPS].) the BIER Encapsulation", of [BIER_ENCAPS].)
In order to create the proper BIER header for a given packet, the In order to create the proper BIER header for a given packet, the
BFIR must know all the BFERs that need to receive that packet. It BFIR must know all the BFERs that need to receive that packet. It
determines this by finding all the Leaf A-D routes that correspond to determines this by finding all the Leaf A-D routes that correspond to
the S-PMSI A-D route that is the packet's match for transmission. the S-PMSI A-D route that is the packet's match for transmission.
There are two different cases to consider: There are two different cases to consider:
1. The S-PMSI A-D route that is the match for transmission carries a 1. The S-PMSI A-D route that is the match for transmission carries a
PTA that has the LIR flag set but does not have the LIR-pF flag PTA that has the LIR flag set but does not have the LIR-pF flag
set. set.
skipping to change at page 9, line 5 skipping to change at page 9, line 23
route. route.
2. The S-PMSI A-D route that is the match for transmission carries a 2. The S-PMSI A-D route that is the match for transmission carries a
PTA that has the LIR-pF flag. PTA that has the LIR-pF flag.
In this case, the corresponding Leaf A-D routes are those whose In this case, the corresponding Leaf A-D routes are those whose
"route key" field is derived from the NLRI of the S-PMSI A-D "route key" field is derived from the NLRI of the S-PMSI A-D
route according to the procedures described in Section 5.2 of route according to the procedures described in Section 5.2 of
[EXPLICIT_TRACKING]. [EXPLICIT_TRACKING].
4.2. Disposition 3.2. Disposition
The procedures for handling a received BIER packet at BFER depend on
whether the BFER is an egress PE for the packet. A BFER can tell
whether it is an egress PE for a given BIER packet by examining the
MPLS label that the packet is carrying immediately after the BIER
header. This will be an upstream-assigned label (from the BFIR) that
has been advertised in the PTA of an S-PMSI A-D route.
Note that if segmented P-tunnels are in use, a BFER might be a
P-tunnel segmentation border router rather than an egress PE, or a
BFER might be both an egress PE and a P-tunnel segmentation border
router.
Depending upon the role of the BFER for given packet, it may need to
follow the procedures of Section 4.2.1, the procedures of
Section 4.2.2, or both.
4.2.1. At a BFER that is an Egress PE
When a BFER receives an MVPN multicast data packet that has been When a BFER receives an MVPN multicast data packet that has been
BIER-encapsulated, it determines from the MPLS label at the top of BIER-encapsulated, the BIER layer passes the following information to
the packet's label stack whether it is an egress PE for the packet or the multicast flow overlay:
not. If it is an egress PE, the BIER layer passes the following
information to the multicast flow layer:
o The BFR-prefix corresponding to the sub-domain-id and BFIR-id in o The BFR-prefix corresponding to the sub-domain-id and BFIR-id in
the BIER header. the BIER header.
o The "payload", which is an MPLS packet whose top label is an o The "payload", which is an MPLS packet whose top label is an
upstream-assigned label. The BFR-prefix provides the "context" in upstream-assigned label. The BFR-prefix provides the "context" in
which the upstream-assigned label is interpreted. which the upstream-assigned label is interpreted.
Note that per [RFC5331], the context for an upstream-assigned Note that per [RFC5331], the context for an upstream-assigned
label is the IP address of the label assigner, which in this case label is the IP address of the label assigner, which in this case
is the BFR-prefix of the BFIR. is the BFR-prefix of the BFIR.
4.2.2. At a BFER that is a P-tunnel Segmentation Boundary By looking up the upstream-assigned label in the appropriate context,
the multicast flow overlay determines whether the BFER is an egress
PE for the packet.
Note that if segmented P-tunnels are in use, a BFER might be a
P-tunnel segmentation border router rather than an egress PE, or a
BFER might be both an egress PE and a P-tunnel segmentation border
router. Depending upon the role of the BFER for given packet, it may
need to follow the procedures of Section 3.2.1, the procedures of
Section 3.2.2, or both.
3.2.1. At a BFER that is an Egress PE
From looking up the packet's upstream-assigned label in the context
of the packet's BFIR-prefix, the egress PE determines the egress VRF
for the packet. From the IP header of the payload, the multicast
states of the VRF, the upstream-assigned label, and the BFR-prefix,
the egress PE can determine whether the packet needs to be forwarded
out one or more VRF interfaces.
3.2.2. At a BFER that is a P-tunnel Segmentation Boundary
When segmented P-tunnels are being used, a BFER that receives a BIER- When segmented P-tunnels are being used, a BFER that receives a BIER-
encapsulated MVPN multicast data packet may need to be forwarded on encapsulated MVPN multicast data packet may need to be forwarded on
its next P-tunnel segment. The choice of the next P-tunnel segment its next P-tunnel segment. The choice of the next P-tunnel segment
for the packet depends upon the C-flow to which the packet belongs. for the packet depends upon the C-flow to which the packet belongs.
Since the BFIR assigns a distinct upstream-assigned MPLS label for As long as the BFIR has assigned the MPLS label according to the
each C-flow, the BFER can select the proper "next P-tunnel segment" constraints specified in Section 2.1, the BFIR will have assigned
for a given packet simply by looking up the upstream-assigned label distinct upstream-assigned MPLS labels to distinct C-flows. The BFER
that immediately follows the BIER header. (If the BFIR had not can thus select the proper "next P-tunnel segment" for a given packet
assigned a distinct label to each C-flow, the BFER would need to simply by looking up the upstream-assigned label that immediately
maintain all the state from the Multicast Flow Overlay in order to follows the BIER header.
select the next P-tunnel segment.)
5. Contributor Addresses 4. Contributor Addresses
Below is a list of other contributing authors in alphabetical order: Below is a list of other contributing authors in alphabetical order:
IJsbrand Wijnands IJsbrand Wijnands
Cisco Systems, Inc. Cisco Systems, Inc.
De Kleetlaan 6a De Kleetlaan 6a
Diegem 1831 Diegem 1831
Belgium Belgium
Email: ice@cisco.com Email: ice@cisco.com
6. Acknowledgments 5. Acknowledgments
The authors wish to thank Jeffrey Zhang for his ideas and The authors wish to thank Jeffrey Zhang for his ideas and
contributions to this work. contributions to this work.
7. IANA Considerations 6. IANA Considerations
IANA is requested to assign a value for "BIER" from the "P-Multicast IANA is requested to assign a value for "BIER" from the "P-Multicast
Service Interface Tunnel (PMSI Tunnel) Tunnel Types" registry. The Service Interface Tunnel (PMSI Tunnel) Tunnel Types" registry. The
reference should be this document. reference should be this document.
8. Security Considerations 7. Security Considerations
The security considerations of [BIER_ARCH], [BIER_ENCAPS], [RFC6513] The security considerations of [BIER_ARCH], [BIER_ENCAPS], [RFC6513]
and [RFC6514] are applicable. and [RFC6514] are applicable.
9. References 8. References
9.1. Normative References 8.1. Normative References
[BIER_ARCH] [BIER_ARCH]
Wijnands, IJ., Rosen, E., Dolganow, A., Przygienda, T., Wijnands, IJ., Rosen, E., Dolganow, A., Przygienda, T.,
and S. Aldrin, "Multicast using Bit Index Explicit and S. Aldrin, "Multicast using Bit Index Explicit
Replication", internet-draft draft-ietf-bier-architecture- Replication", internet-draft draft-ietf-bier-architecture-
03, January 2016. 03, January 2016.
[BIER_ENCAPS] [BIER_ENCAPS]
Wijnands, IJ., Rosen, E., Dolganow, A., Tantsura, J., and Wijnands, IJ., Rosen, E., Dolganow, A., Tantsura, J., and
S. Aldrin, "Encapsulation for Bit Index Explicit S. Aldrin, "Encapsulation for Bit Index Explicit
skipping to change at page 11, line 33 skipping to change at page 12, line 5
[RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP [RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
Encodings and Procedures for Multicast in MPLS/BGP IP Encodings and Procedures for Multicast in MPLS/BGP IP
VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012, VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012,
<http://www.rfc-editor.org/info/rfc6514>. <http://www.rfc-editor.org/info/rfc6514>.
[RFC6625] Rosen, E., Ed., Rekhter, Y., Ed., Hendrickx, W., and R. [RFC6625] Rosen, E., Ed., Rekhter, Y., Ed., Hendrickx, W., and R.
Qiu, "Wildcards in Multicast VPN Auto-Discovery Routes", Qiu, "Wildcards in Multicast VPN Auto-Discovery Routes",
RFC 6625, DOI 10.17487/RFC6625, May 2012, RFC 6625, DOI 10.17487/RFC6625, May 2012,
<http://www.rfc-editor.org/info/rfc6625>. <http://www.rfc-editor.org/info/rfc6625>.
9.2. Informative References 8.2. Informative References
[EXPLICIT_TRACKING] [EXPLICIT_TRACKING]
Dolganow, A., Kotalwar, J., Rosen, E., and Z. Zhang, Dolganow, A., Kotalwar, J., Rosen, E., and Z. Zhang,
"Explicit Tracking with Wild Card Routes in Multicast "Explicit Tracking with Wild Card Routes in Multicast
VPN", internet-draft draft-ietf-bess-mvpn-expl-track-00, VPN", internet-draft draft-ietf-bess-mvpn-expl-track-00,
June 2016. June 2016.
[EXTRANET]
Rekhter, Y., Rosen, E., Aggarwal, R., Cai, Y., and T.
Morin, "Extranet Multicast in BGP/IP MPLS VPNs", internet-
draft draft-ietf-bess-mvpn-extranet-07, April 2016.
[RFC7524] Rekhter, Y., Rosen, E., Aggarwal, R., Morin, T., [RFC7524] Rekhter, Y., Rosen, E., Aggarwal, R., Morin, T.,
Grosclaude, I., Leymann, N., and S. Saad, "Inter-Area Grosclaude, I., Leymann, N., and S. Saad, "Inter-Area
Point-to-Multipoint (P2MP) Segmented Label Switched Paths Point-to-Multipoint (P2MP) Segmented Label Switched Paths
(LSPs)", RFC 7524, DOI 10.17487/RFC7524, May 2015, (LSPs)", RFC 7524, DOI 10.17487/RFC7524, May 2015,
<http://www.rfc-editor.org/info/rfc7524>. <http://www.rfc-editor.org/info/rfc7524>.
[RFC7900] Rekhter, Y., Ed., Rosen, E., Ed., Aggarwal, R., Cai, Y.,
and T. Morin, "Extranet Multicast in BGP/IP MPLS VPNs",
RFC 7900, DOI 10.17487/RFC7900, June 2016,
<http://www.rfc-editor.org/info/rfc7900>.
Authors' Addresses Authors' Addresses
Eric C. Rosen (editor) Eric C. Rosen (editor)
Juniper Networks, Inc. Juniper Networks, Inc.
10 Technology Park Drive 10 Technology Park Drive
Westford, Massachusetts 01886 Westford, Massachusetts 01886
United States United States
Email: erosen@juniper.net Email: erosen@juniper.net
skipping to change at page 12, line 30 skipping to change at page 13, line 4
Email: masivaku@cisco.com Email: masivaku@cisco.com
Sam K Aldrin Sam K Aldrin
Google, Inc. Google, Inc.
1600 Amphitheatre Parkway 1600 Amphitheatre Parkway
Mountain View, California Mountain View, California
United States United States
Email: aldrin.ietf@gmail.com Email: aldrin.ietf@gmail.com
Andrew Dolganow Andrew Dolganow
Alcatel-Lucent Nokia
600 March Rd. 600 March Rd.
Ottawa, Ontario K2K 2E6 Ottawa, Ontario K2K 2E6
Canada Canada
Email: andrew.dolganow@alcatel-lucent.com Email: andrew.dolganow@nokia.com
Tony Przygienda Tony Przygienda
Ericsson Juniper Networks, Inc.
300 Holger Way 1137 Innovation Way
San Jose, California 95134 San Jose, California 94089
United States United States
Email: antoni.przygienda@ericsson.com Email: prz@juniper.net
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