draft-ietf-softwire-mesh-multicast-17.txt   draft-ietf-softwire-mesh-multicast-18.txt 
Softwire WG M. Xu Softwire WG M. Xu
Internet-Draft Y. Cui Internet-Draft Y. Cui
Intended status: Standards Track J. Wu Intended status: Standards Track J. Wu
Expires: February 4, 2018 S. Yang Expires: March 28, 2018 S. Yang
Tsinghua University Tsinghua University
C. Metz C. Metz
G. Shepherd G. Shepherd
Cisco Systems Cisco Systems
August 3, 2017 September 24, 2017
Softwire Mesh Multicast Softwire Mesh Multicast
draft-ietf-softwire-mesh-multicast-17 draft-ietf-softwire-mesh-multicast-18
Abstract Abstract
The Internet needs to support IPv4 and IPv6 packets. Both address The Internet needs to support IPv4 and IPv6 packets. Both address
families and their related protocol suites support multicast of the families and their related protocol suites support multicast of the
single-source and any-source varieties. During IPv6 transition, single-source and any-source varieties. During IPv6 transition,
there will be scenarios where a backbone network running one IP there will be scenarios where a backbone network running one IP
address family internally (referred to as internal IP or I-IP), while address family internally (referred to as internal IP or I-IP), while
the attached client networks running another IP address family the attached client networks running another IP address family
(referred to as external IP or E-IP). The I-IP backbone should offer (referred to as external IP or E-IP). The I-IP backbone should offer
skipping to change at page 1, line 43 skipping to change at page 1, line 43
cases for IPv6-over-IPv4 scenario. cases for IPv6-over-IPv4 scenario.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 https://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 February 4, 2018. This Internet-Draft will expire on March 28, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Scenarios of Interest . . . . . . . . . . . . . . . . . . . . 6 3. Scenarios of Interest . . . . . . . . . . . . . . . . . . . . 6
4. IPv4-over-IPv6 Mechanism . . . . . . . . . . . . . . . . . . 7 4. IPv4-over-IPv6 Mechanism . . . . . . . . . . . . . . . . . . 7
4.1. Mechanism Overview . . . . . . . . . . . . . . . . . . . 8 4.1. Mechanism Overview . . . . . . . . . . . . . . . . . . . 8
4.2. Group Address Mapping . . . . . . . . . . . . . . . . . . 8 4.2. Group Address Mapping . . . . . . . . . . . . . . . . . . 8
4.3. Source Address Mapping . . . . . . . . . . . . . . . . . 9 4.3. Source Address Mapping . . . . . . . . . . . . . . . . . 9
4.4. Routing Mechanism . . . . . . . . . . . . . . . . . . . . 10 4.4. Routing Mechanism . . . . . . . . . . . . . . . . . . . . 10
5. Control Plane Functions of AFBR . . . . . . . . . . . . . . . 11 5. Control Plane Functions of AFBR . . . . . . . . . . . . . . . 11
5.1. E-IP (*,G) State Maintenance . . . . . . . . . . . . . . 11 5.1. E-IP (*,G) and (S,G) State Maintenance . . . . . . . . . 11
5.2. E-IP (S,G) State Maintenance . . . . . . . . . . . . . . 11 5.2. I-IP (S',G') State Maintenance . . . . . . . . . . . . . 11
5.3. I-IP (S',G') State Maintenance . . . . . . . . . . . . . 11 5.3. E-IP (S,G,rpt) State Maintenance . . . . . . . . . . . . 11
5.4. E-IP (S,G,rpt) State Maintenance . . . . . . . . . . . . 11 5.4. Inter-AFBR Signaling . . . . . . . . . . . . . . . . . . 11
5.5. Inter-AFBR Signaling . . . . . . . . . . . . . . . . . . 12 5.5. SPT Switchover . . . . . . . . . . . . . . . . . . . . . 14
5.6. SPT Switchover . . . . . . . . . . . . . . . . . . . . . 14 5.6. Other PIM Message Types . . . . . . . . . . . . . . . . . 14
5.7. Other PIM Message Types . . . . . . . . . . . . . . . . . 14 5.7. Other PIM States Maintenance . . . . . . . . . . . . . . 14
5.8. Other PIM States Maintenance . . . . . . . . . . . . . . 14
6. Data Plane Functions of the AFBR . . . . . . . . . . . . . . 14 6. Data Plane Functions of the AFBR . . . . . . . . . . . . . . 14
6.1. Process and Forward Multicast Data . . . . . . . . . . . 14 6.1. Process and Forward Multicast Data . . . . . . . . . . . 14
6.2. TTL . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.2. TTL . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.3. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 15 6.3. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 15
7. Packet Format and Translation . . . . . . . . . . . . . . . . 15 7. Packet Format and Translation . . . . . . . . . . . . . . . . 15
8. Softwire Mesh Multicast Encapsulation . . . . . . . . . . . . 16 8. Softwire Mesh Multicast Encapsulation . . . . . . . . . . . . 16
9. Security Considerations . . . . . . . . . . . . . . . . . . . 17 9. Security Considerations . . . . . . . . . . . . . . . . . . . 17
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 17 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
11.1. Normative References . . . . . . . . . . . . . . . . . . 17 11.1. Normative References . . . . . . . . . . . . . . . . . . 17
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| mPrefix46 |group address | | mPrefix46 |group address |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
Figure 4: IPv4-Embedded IPv6 Multicast Address Format Figure 4: IPv4-Embedded IPv6 Multicast Address Format
An IPv6 multicast prefix (mPrefix46) is assigned to each AFBR. AFBRs An IPv6 multicast prefix (mPrefix46) is assigned to each AFBR. AFBRs
will prepend the prefix to an IPv4 multicast group address when will prepend the prefix to an IPv4 multicast group address when
translating it to an IPv6 multicast group address. translating it to an IPv6 multicast group address.
The mPrefix46 for SSM mode is also defined in Section 2 of [RFC8114]. The construction of the mPrefix46 for SSM is the same as the
construction of the mPrefix64 described in Section 5 of [RFC8114].
With this scheme, each IPv4 multicast address can be mapped into an With this scheme, each IPv4 multicast address can be mapped into an
IPv6 multicast address (with the assigned prefix), and each IPv6 IPv6 multicast address (with the assigned prefix), and each IPv6
multicast address with the assigned prefix can be mapped into an IPv4 multicast address with the assigned prefix can be mapped into an IPv4
multicast address. The group address translation algorithm can be multicast address. The group address translation algorithm can be
reffered in Section 5.2 of [RFC8114]. reffered in Section 5.2 of [RFC8114].
4.3. Source Address Mapping 4.3. Source Address Mapping
There are two kinds of multicast: ASM and SSM. Considering that the There are two kinds of multicast: ASM and SSM. Considering that the
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4.4. Routing Mechanism 4.4. Routing Mechanism
In the mesh multicast scenario, routing information is REQUIRED to be In the mesh multicast scenario, routing information is REQUIRED to be
distributed among AFBRs to make sure that the PIM messages that a distributed among AFBRs to make sure that the PIM messages that a
downstream AFBR propagates reach the right upstream AFBR. downstream AFBR propagates reach the right upstream AFBR.
Every AFBR MUST know the /32 prefix in "IPv4-Embedded IPv6 Virtual Every AFBR MUST know the /32 prefix in "IPv4-Embedded IPv6 Virtual
Source Address Format". To achieve this, every AFBR should announce Source Address Format". To achieve this, every AFBR should announce
one of its E-IPv4 interfaces in the "v4" field, and the corresponding one of its E-IPv4 interfaces in the "v4" field, and the corresponding
uPrefix46. The announcement SHOULD be sent to the other AFBRs uPrefix46. The announcement SHOULD be sent to the other AFBRs
through MBGP. Since every IP address of upstream AFBR's E-IPv4 through MBGP [RFC4760]. Since every IP address of upstream AFBR's
interface is different from each other, every uPrefix46 that AFBR E-IPv4 interface is different from each other, every uPrefix46 that
announces MUST be different, and uniquely identifies each AFBR. AFBR announces MUST be different, and uniquely identifies each AFBR.
"uPrefix46" is an IPv6 prefix, and the distribution mechanism is the "uPrefix46" is an IPv6 prefix, and the distribution mechanism is the
same as the traditional mesh unicast scenario. But "v4" field is an same as the traditional mesh unicast scenario. But "v4" field is an
E-IPv4 address, and BGP messages are NOT tunneled through softwires E-IPv4 address, and BGP messages are NOT tunneled through softwires
or any other mechanism specified in [RFC5565], AFBRs MUST be able to or any other mechanism specified in [RFC5565], AFBRs MUST be able to
transport and encode/decode BGP messages that are carried over transport and encode/decode BGP messages that are carried over
I-IPv6, whose NLRI and NH are of E-IPv4 address family. I-IPv6, whose NLRI and NH are of E-IPv4 address family.
In this way, when a downstream AFBR receives an E-IPv4 PIM (S,G) In this way, when a downstream AFBR receives an E-IPv4 PIM (S,G)
message, it can translate this message into (S',G') by looking up the message, it can translate this message into (S',G') by looking up the
IP address of the corresponding AFBR's E-IPv4 interface. Since the IP address of the corresponding AFBR's E-IPv4 interface. Since the
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able to map a particular multicast group address to the same RP (see able to map a particular multicast group address to the same RP (see
Section 4.7 of [RFC7761]), when the upstream AFBR checks the "source Section 4.7 of [RFC7761]), when the upstream AFBR checks the "source
address" field of the message, it finds the IPv4 address of the RP, address" field of the message, it finds the IPv4 address of the RP,
and assertains that this is originally a (*,G) message. This is then and assertains that this is originally a (*,G) message. This is then
translated back to the (*,G) message and processed. translated back to the (*,G) message and processed.
5. Control Plane Functions of AFBR 5. Control Plane Functions of AFBR
AFBRs are responsible for the following functions: AFBRs are responsible for the following functions:
5.1. E-IP (*,G) State Maintenance 5.1. E-IP (*,G) and (S,G) State Maintenance
When an AFBR wishes to propagate a Join/Prune(*,G) message to an I-IP
upstream router, the AFBR MUST translate Join/Prune(*,G) messages
into Join/Prune(S',G') messages following the rules specified above,
then send the latter.
5.2. E-IP (S,G) State Maintenance
When an AFBR wishes to propagate a Join/Prune(S,G) message to an I-IP E-IP (*,G) and (S,G) state maintenance on AFBR is the same as E-IP
upstream router, the AFBR MUST translate Join/Prune(S,G) messages (*,G) and (S,G) state maintenance on mAFTR described in Section 7.2
into Join/Prune(S',G') messages following the rules specified above, of [RFC8114]
then send the latter.
5.3. I-IP (S',G') State Maintenance 5.2. I-IP (S',G') State Maintenance
It is possible that the I-IP transit core runs another non-transit It is possible that the I-IP transit core runs another non-transit
I-IP PIM-SSM instance. Since the translated source address starts I-IP PIM-SSM instance. Since the translated source address starts
with the unique "Well-Known" prefix or the ISP-defined prefix that with the unique "Well-Known" prefix or the ISP-defined prefix that
SHOULD NOT be used by other service provider, mesh multicast will not SHOULD NOT be used by other service provider, mesh multicast will not
influence non-transit PIM-SSM multicast at all. When an AFBR influence non-transit PIM-SSM multicast at all. When an AFBR
receives an I-IP (S',G') message, it MUST check S'. If S' starts receives an I-IP (S',G') message, it MUST check S'. If S' starts
with the unique prefix, then the message is actually a translated with the unique prefix, then the message is actually a translated
E-IP (S,G) or (*,G) message, and the AFBR MUST translate this message E-IP (S,G) or (*,G) message, and the AFBR MUST translate this message
back to E-IP PIM message and process it. back to E-IP PIM message and process it.
5.4. E-IP (S,G,rpt) State Maintenance 5.3. E-IP (S,G,rpt) State Maintenance
When an AFBR wishes to propagate a Join/Prune(S,G,rpt) message to an When an AFBR wishes to propagate a Join/Prune(S,G,rpt) message to an
I-IP upstream router, the AFBR MUST operate as specified in I-IP upstream router, the AFBR MUST operate as specified in
Section 6.5 and Section 6.6. Section 6.5 and Section 6.6.
5.5. Inter-AFBR Signaling 5.4. Inter-AFBR Signaling
Assume that one downstream AFBR has joined a RPT of (*,G) and a SPT Assume that one downstream AFBR has joined a RPT of (*,G) and a SPT
of (S,G), and decide to perform an SPT switchover. According to of (S,G), and decide to perform an SPT switchover. According to
[RFC7761], it SHOULD propagate a Prune(S,G,rpt) message along with [RFC7761], it SHOULD propagate a Prune(S,G,rpt) message along with
the periodical Join(*,G) message upstream towards RP. However, the periodical Join(*,G) message upstream towards RP. However,
routers in the I-IP transit core do not process (S,G,rpt) messages routers in the I-IP transit core do not process (S,G,rpt) messages
since the I-IP transit core is treated as SSM-only. As a result, the since the I-IP transit core is treated as SSM-only. As a result, the
downstream AFBR is unable to prune S from this RPT, so it will downstream AFBR is unable to prune S from this RPT, so it will
receive two copies of the same data of (S,G). In order to solve this receive two copies of the same data of (S,G). In order to solve this
problem, we introduce a new mechanism for downstream AFBRs to inform problem, we introduce a new mechanism for downstream AFBRs to inform
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When RP' receives this encapsulated message, it SHOULD decapsulate When RP' receives this encapsulated message, it SHOULD decapsulate
the message as in the unicast scenario, and retrieve the original the message as in the unicast scenario, and retrieve the original
(S,G,rpt) message. The incoming interface of this message may be (S,G,rpt) message. The incoming interface of this message may be
different to the outgoing interface which propagates multicast data different to the outgoing interface which propagates multicast data
to the corresponding downstream AFBR, and there may be other to the corresponding downstream AFBR, and there may be other
downstream AFBRs that need to receive multicast data of (S,G) from downstream AFBRs that need to receive multicast data of (S,G) from
this incoming interface, so RP' SHOULD NOT simply process this this incoming interface, so RP' SHOULD NOT simply process this
message as specified in [RFC7761] on the incoming interface. message as specified in [RFC7761] on the incoming interface.
To solve this problem as simply as possible, we introduce an To solve this problem, we introduce an "interface agent" to process
"interface agent" to process all the encapsulated (S,G,rpt) messages all the encapsulated (S,G,rpt) messages the upstream AFBR receives.
the upstream AFBR receives, and RP' SHOULD prune S from the RPT of The interface agent's RP' SHOULD prune S from the RPT of group G when
group G when no downstream AFBR is subscribed to receive multicast no downstream AFBR is subscribed to receive multicast data of (S,G)
data of (S,G) along the RPT. In this way, we ensure that downstream along the RPT.
AFBRs will not miss any multicast data that they need, at the cost of
duplicated multicast data of (S,G) along the RPT received by SPT- In this way, we ensure that downstream AFBRs will not miss any
multicast data that they need. The cost of this is that multicast
data of (S,G) will be duplicated along the RPT received by SPT-
switched-over downstream AFBRs, if at least one downstream AFBR switched-over downstream AFBRs, if at least one downstream AFBR
exists that has not yet sent Prune(S,G,rpt) messages to the upstream exists that has not yet sent Prune(S,G,rpt) messages to the upstream
AFBR. The mechanism used to achieve this is left to the AFBR.
implementation, the following diagram provides a possible solution
that "interface agent" MAY be implemented: In certain deployment scenarios (e.g. if there is only a single
downstream router), the interface agent function is not required.
The mechanism used to achieve this is left to the implementation.
The following diagram provides one possible solution for an
"interface agent" implementation:
+----------------------------------------+ +----------------------------------------+
| | | |
| +-----------+----------+ | | +-----------+----------+ |
| | PIM-SM | UDP | | | | PIM-SM | UDP | |
| +-----------+----------+ | | +-----------+----------+ |
| ^ | | | ^ | |
| | | | | | | |
| | v | | | v |
| +----------------------+ | | +----------------------+ |
skipping to change at page 14, line 7 skipping to change at page 14, line 7
means that the corresponding downstream AFBR has switched to receive means that the corresponding downstream AFBR has switched to receive
multicast data of (S,G) along the RPT again, the interface agent multicast data of (S,G) along the RPT again, the interface agent
SHOULD send a Join (S,G,rpt) to the PIM-SM module immediately. SHOULD send a Join (S,G,rpt) to the PIM-SM module immediately.
In the data plane, upon receiving a multicast data packet, the In the data plane, upon receiving a multicast data packet, the
interface agent SHOULD encapsulate it at first, then propagate the interface agent SHOULD encapsulate it at first, then propagate the
encapsulated packet from every I-IP interface. encapsulated packet from every I-IP interface.
NOTICE: It is possible that an E-IP neighbor of RP' that has joined NOTICE: It is possible that an E-IP neighbor of RP' that has joined
the RPT of G, so the per-interface state machine for receiving E-IP the RPT of G, so the per-interface state machine for receiving E-IP
Join/Prune (S,G,rpt) messages SHOULD keep alive. Join/Prune (S,G,rpt) messages SHOULD be preserved.
5.6. SPT Switchover 5.5. SPT Switchover
After a new AFBR requests the receipt of traffic destined for a After a new AFBR requests the receipt of traffic destined for a
multicast group, it will receive all the data from the RPT at first. multicast group, it will receive all the data from the RPT at first.
At this time, every downstream AFBR will receive multicast data from At this time, every downstream AFBR will receive multicast data from
any source from this RPT, in spite of whether they have switched over any source from this RPT, in spite of whether they have switched over
to an SPT of some source(s) or not. to an SPT of some source(s) or not.
To minimize this redundancy, it is recommended that every AFBR's To minimize this redundancy, it is recommended that every AFBR's
SwitchToSptDesired(S,G) function employs the "switch on first packet" SwitchToSptDesired(S,G) function employs the "switch on first packet"
policy. In this way, the delay in switchover to SPT is kept as small policy. In this way, the delay in switchover to SPT is kept as small
as possible, and after the moment that every AFBR has performed the as possible, and after the moment that every AFBR has performed the
SPT switchover for every S of group G, no data will be forwarded in SPT switchover for every S of group G, no data will be forwarded in
the RPT of G, thus no more unnecessary duplication will be produced. the RPT of G, thus no more unnecessary duplication will be produced.
5.7. Other PIM Message Types 5.6. Other PIM Message Types
In addition to Join or Prune, other message types exist, including In addition to Join or Prune, other message types exist, including
Register, Register-Stop, Hello and Assert. Register and Register- Register, Register-Stop, Hello and Assert. Register and Register-
Stop messages are sent by unicast, while Hello and Assert messages Stop messages are sent by unicast, while Hello and Assert messages
are only used between directly linked routers to negotiate with each are only used between directly linked routers to negotiate with each
other. It is not necessary to translate these for forwarding, thus other. It is not necessary to translate these for forwarding, thus
the processing of these messages is out of scope for this document. the processing of these messages is out of scope for this document.
5.8. Other PIM States Maintenance 5.7. Other PIM States Maintenance
In addition to states mentioned above, other states exist, including In addition to states mentioned above, other states exist, including
(*,*,RP) and I-IP (*,G') state. Since we treat the I-IP core as SSM- (*,*,RP) and I-IP (*,G') state. Since we treat the I-IP core as SSM-
only, the maintenance of these states is out of scope for this only, the maintenance of these states is out of scope for this
document. document.
6. Data Plane Functions of the AFBR 6. Data Plane Functions of the AFBR
6.1. Process and Forward Multicast Data 6.1. Process and Forward Multicast Data
On receiving multicast data from upstream routers, the AFBR checks The data plane behavior on AFBR is similar with the data plane
its forwarding table to find the IP address of each outgoing behavior on mAFTR described in Section 7.4 of [RFC8114]. If there is
interface. If there is at least one outgoing interface whose IP at least one outgoing interface whose IP address family is different
address family is different from the incoming interface, the AFBR from the incoming interface, the AFBR MUST encapsulate this packet
MUST encapsulate/decapsulate this packet and forward it via the with mPrefix46-derived and uPrefix46-derived IPv6 address to form an
outgoing interface(s), then forward the data via other outgoing IPv6 multicast packet.
interfaces without encapsulation/decapsulation.
When a downstream AFBR that has already switched over to the SPT of S
receives an encapsulated multicast data packet of (S,G) along the
RPT, it SHOULD silently drop this packet.
6.2. TTL 6.2. TTL
Processing of TTL information in protocol headers depends on the Processing of TTL information in protocol headers depends on the
tunneling technology, and it is out of scope of this document. tunneling technology, and it is out of scope of this document.
6.3. Fragmentation 6.3. Fragmentation
The encapsulation performed by an upstream AFBR will increase the The encapsulation performed by an upstream AFBR will increase the
size of packets. As a result, the outgoing I-IP link MTU may not size of packets. As a result, the outgoing I-IP link MTU may not
skipping to change at page 17, line 26 skipping to change at page 17, line 26
This document includes no request to IANA. This document includes no request to IANA.
11. References 11. References
11.1. Normative References 11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <http://www.rfc-editor.org/info/rfc4291>. 2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the [RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <http://www.rfc-editor.org/info/rfc4301>. December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
[RFC4925] Li, X., Ed., Dawkins, S., Ed., Ward, D., Ed., and A. [RFC4925] Li, X., Ed., Dawkins, S., Ed., Ward, D., Ed., and A.
Durand, Ed., "Softwire Problem Statement", RFC 4925, Durand, Ed., "Softwire Problem Statement", RFC 4925,
DOI 10.17487/RFC4925, July 2007, DOI 10.17487/RFC4925, July 2007,
<http://www.rfc-editor.org/info/rfc4925>. <https://www.rfc-editor.org/info/rfc4925>.
[RFC5565] Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh [RFC5565] Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh
Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009, Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009,
<http://www.rfc-editor.org/info/rfc5565>. <https://www.rfc-editor.org/info/rfc5565>.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
DOI 10.17487/RFC6052, October 2010, DOI 10.17487/RFC6052, October 2010,
<http://www.rfc-editor.org/info/rfc6052>. <https://www.rfc-editor.org/info/rfc6052>.
[RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/ [RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
2012, <http://www.rfc-editor.org/info/rfc6513>. 2012, <https://www.rfc-editor.org/info/rfc6513>.
[RFC7761] Fenner, B., Handley, M., Holbrook, H., Kouvelas, I., [RFC7761] Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent
Multicast - Sparse Mode (PIM-SM): Protocol Specification Multicast - Sparse Mode (PIM-SM): Protocol Specification
(Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March
2016, <http://www.rfc-editor.org/info/rfc7761>. 2016, <https://www.rfc-editor.org/info/rfc7761>.
[RFC8114] Boucadair, M., Qin, C., Jacquenet, C., Lee, Y., and Q. [RFC8114] Boucadair, M., Qin, C., Jacquenet, C., Lee, Y., and Q.
Wang, "Delivery of IPv4 Multicast Services to IPv4 Clients Wang, "Delivery of IPv4 Multicast Services to IPv4 Clients
over an IPv6 Multicast Network", RFC 8114, over an IPv6 Multicast Network", RFC 8114,
DOI 10.17487/RFC8114, March 2017, DOI 10.17487/RFC8114, March 2017,
<http://www.rfc-editor.org/info/rfc8114>. <https://www.rfc-editor.org/info/rfc8114>.
11.2. Informative References 11.2. Informative References
[RFC7371] Boucadair, M. and S. Venaas, "Updates to the IPv6 [RFC7371] Boucadair, M. and S. Venaas, "Updates to the IPv6
Multicast Addressing Architecture", RFC 7371, Multicast Addressing Architecture", RFC 7371,
DOI 10.17487/RFC7371, September 2014, DOI 10.17487/RFC7371, September 2014,
<http://www.rfc-editor.org/info/rfc7371>. <https://www.rfc-editor.org/info/rfc7371>.
Appendix A. Acknowledgements Appendix A. Acknowledgements
Wenlong Chen, Xuan Chen, Alain Durand, Yiu Lee, Jacni Qin and Stig Wenlong Chen, Xuan Chen, Alain Durand, Yiu Lee, Jacni Qin and Stig
Venaas provided useful input into this document. Venaas provided useful input into this document.
Authors' Addresses Authors' Addresses
Mingwei Xu Mingwei Xu
Tsinghua University Tsinghua University
Department of Computer Science, Tsinghua University Department of Computer Science, Tsinghua University
Beijing 100084 Beijing 100084
P.R. China P.R. China
Phone: +86-10-6278-5822 Phone: +86-10-6278-5822
Email: xumwcs@gmail.com Email: xumw@tsinghua.edu.cn
Yong Cui Yong Cui
Tsinghua University Tsinghua University
Department of Computer Science, Tsinghua University Department of Computer Science, Tsinghua University
Beijing 100084 Beijing 100084
P.R. China P.R. China
Phone: +86-10-6278-5822 Phone: +86-10-6278-5822
Email: cuiyong@tsinghua.edu.cn Email: cuiyong@tsinghua.edu.cn
Jianping Wu Jianping Wu
Tsinghua University Tsinghua University
Department of Computer Science, Tsinghua University Department of Computer Science, Tsinghua University
Beijing 100084 Beijing 100084
P.R. China P.R. China
Phone: +86-10-6278-5983 Phone: +86-10-6278-5983
Email: jianping@cernet.edu.cn Email: jianping@cernet.edu.cn
Shu Yang Shu Yang
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