Internet DRAFT - draft-li-pce-pcep-extension-multicast-management
draft-li-pce-pcep-extension-multicast-management
PCE Working Group H. Li
Internet-Draft A. Wang
Intended status: Standards Track China Telecom
Expires: November 25, 2021 H. Chen
Futurewei
C. Zhu
ZTE Corporation
May 24, 2021
PCEP Extension for Multicast Management
draft-li-pce-pcep-extension-multicast-management-00
Abstract
This document describes extensions to Path Computation Element (PCE)
communication Protocol (PCEP) for supporting multicast service
management.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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This Internet-Draft will expire on November 25, 2021.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview of Using PCE for multicast service management . . . 4
5. PCEP message . . . . . . . . . . . . . . . . . . . . . . . . 5
5.1. PCRpt message . . . . . . . . . . . . . . . . . . . . . . 5
5.2. PCUpd message . . . . . . . . . . . . . . . . . . . . . . 6
6. Object formats . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Multicast source registration object . . . . . . . . . . 7
6.1.1. IPv4 multicast TLV . . . . . . . . . . . . . . . . . 7
6.1.2. IPv6 multicast TLV . . . . . . . . . . . . . . . . . 9
6.2. Multicast receiver information object . . . . . . . . . . 10
6.3. Forwarding indication object . . . . . . . . . . . . . . 11
7. Deployment Considerations . . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
10. Contributor . . . . . . . . . . . . . . . . . . . . . . . . . 12
11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 12
12. Normative References . . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Currently, multicast management information is mainly signaled by PIM
[RFC2362] or BGP [RFC6514], which have some limitations in the
deployment and process.
[RFC4655] defines a stateful PCE to be one in which the PCE maintains
"strict synchronization between the PCE and not only the network
states (in term of topology and resource information), but also the
set of computed paths and reserved resources in use in the network."
[RFC8231] specifies a set of extensions to PCEP to support state
synchronization between PCCs and PCEs.
[RFC8279] defines a Bit Index Explicit Replication (BIER)
architecture where all intended multicast receivers are encoded as a
bitmask in the multicast packet header within different
encapsulations such as described in [RFC8296] . A router that
receives such a packet will forward the packet based on the bit
position in the packet header towards the receiver(s) following a
precomputed tree for each of the bits in the packet. Each receiver
is represented by a unique bit in the bitmask.
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This document spceifies PCEP protocol extensions to optimize the
implementation of multicast source registration/revocation, receiver
automatic discovery,and forwarding control of multicast data by using
PCEP messages to transmit multicast management signaling, combining
with the forwarding characteristics of BIER.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Terminology
The following terms are used in this document:
o BFR-id: BFR Identifier. It is a number in the range [1,65535]
o BGP: Border Gateway Protocol
o BIER: Bit Index Explicit Replication
o BIFT: Bit Index Forwarding Table
o FI: Forwarding indication
o IGMP: Internet Group Management Protocol
o IGP: Interior Gateway Protocols
o MLD: Multicast Listener Discover
o MRI: Multicast Receiver Information
o MSR: Multicast Source Registration
o PCC: Path Computation Client
o PCE: Path Computation Element
o PCEP: PCE communication Protocol
o PIM: Protocol Independent Multicast
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4. Overview of Using PCE for multicast service management
Multicast service management includes multicast source registration
information management, multicast receiver information management and
multicast data forwarding control.
Multicast source registration information includes registration and
processing of multicast group and source information.
Multicast receiver information includes requesting multicast group,
multicast source and VPN information.
Multicast data forwarding control includes BitString calculation and
data forwarding.
PCRpt message and PCUpd message, described in [RFC8231], are used in
the multicast service management process.
The specific implementation process is as follows:
+------------------+
+ Controller +
+-----------+ PCE +----------+
| +--------^---------+ |
| |
| |
1 | 4 +--------+ | 3
| -----------+ R3 +------------ |
| / +--------+ \ |
| / \ |
+-------+ +--+ +--+ +--+ +--+ 2 +--------+
|Sourece|-----|R1+----------+R5+----------+R6+---------+R7|-----|Receiver|
+-------+ +--+ +--+ +--+ +--+ +--------+
| |
| +--+ +--+ |
+------------+R2+----------+R4+-----------+
+--+ +--+
Figure 1: Example Multicast management Topology with PCE(controller as PCE)
Step 1 : The source-side PCC R1 sends multicast group and source
information to the controller about multicast information
registration via PCRpt message. Then the controller stores the
multicast registration information into the database.
Step 2 : Receivers send IGMP/MLD messages to the receiver-side PCC R7
requesting to join/leave a multicast group.
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Step3 : The receiver-side PCC R7 converts the IGMP/MLD messages into
PCRpt message and send it to the controller. The information of IGMP
Membership Report messages should be convert to IPv4 Multicast TLV.
The information of MLD Membership Report messages should be convert
to IPv6 Multicast TLV. These TLVs are defined in section 6.1.
Furthermore, PCC should not send PCRpt message with join information
to the controller if the receiver is not the first one to joining the
multicast group. PCC should not send PCRpt message with leaving
information to the controller if the receiver is not the last one to
leave the multicast group.
Step 4 : If the multicast group and multicast source information
requested by the receiver has registered, the controller calculates
the forwarding path and sends it to the source-side PCC R1 via PCUpd
message in the form of BitString to control data forwarding. The
source-side PCC encapsulates BIER header and forwards them based on
BIFT and BitString when receving multicast packets.
This document specifies PCEP protocol extensions for multicast group
management, including multicast source registration (MSR) object,
multicast receiver information (MRI) object, forwarding indication
(FI) object, two TLVs and extensions to PCRpt message and PCUpd
message.
5. PCEP message
5.1. PCRpt message
A PCC should include the MSR object (see Section 6.1) in the PCRpt
message if the PCC wants to register multicast source information
with the PCE. And a PCC MAY include the MRI object (see Section 6.2)
in the PCRpt message if the PCC wants to send multcast join messages
to a PCE.
The definition of the PCRpt message from [RFC8231] is extended to
optionally include the MSR object and the MRI object after the path
object. The encoding from [RFC8231] will become:
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<PCRpt Message> ::= <Common Header>
<state-report-list>
Where:
<state-report-list> ::= <state-report>[<state-report-list>]
<state-report> ::= [<SRP>]
<LSP>
<path>
[<MSR>]
[<MRI>]
Where:
<path> is as per [RFC8231] and the LSP and SRP object are
also defined in [RFC8231].
5.2. PCUpd message
A PCE should include the FI object in the PCUpd message (see
Section 6.3) if the PCE wants to send the BitString to the PCC to
indicate the path of multicast data packets forwarding for PCC.
The definition of the PCUpd message from [RFC8231] is extended to
optionally include the FI object after the path object. The encoding
from [RFC8231] will become:
<PCUpd Message> ::= <Common Header>
<update-request-list>
Where:
<update-request-list> ::= <update-request>[<update-request-list>]
<update-request> ::= <SRP>
<LSP>
<path>
[<FI>]
Where:
<path> is as per [RFC8231] and the LSP and SRP object are
also defined in [RFC8231].
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6. Object formats
6.1. Multicast source registration object
The MSR object is optional and specifies multicast group and source
information in multicast registration information management. The
MSR Objcet should be carried within a PCReq message sent by the PCC
to the PCE in muticast scenarios.
MSR Object-Class is TBD1. MSRObject-Type is 1.
The format of the MSR objcet body is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subdomain-id | BFR-ID | BSL |Flags|R|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: MSR Object Body Format
Subdomain-id(8 bits): Unique value identifying the BIER subdomain.
BFR-ID (16 bits): Identification of BFR in a subdomain.
BSL(BitString Length, 4 bits): encodes the length in bits of the
BitString as per[RFC8296] , the maximum length of the BitString is 7,
it indicates the length of BitString is 4096.It is used to refer to
the number of bits in the BitString.
Flags (3 bits): This field MUST be set to zero on transmission and
MUST be ignored on receipt.
R (Register flag - 1 bit): The R flag set to 1 indicates that the PCC
is registering multicast information to the PCE. The R flag set to 0
indicates that the PCC revokes the register.
The specific format of two TLVs are as follows:
6.1.1. IPv4 multicast TLV
The format of the IPv4 Multicast TLV is shown in the following
figure:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=TBD2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RD |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Multicast Source address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Groups(N) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Multicast Group address [1] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
| . |
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Multicast Group address [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Auxliary Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: IPv4 Multicast TLV Format
The type of the TLV is TBD.
RD(Route Distinguisher(8 bytes): indicates the VPN which the receiver
used.
IPv4 Multicast Source Address(32 bits): contains IPv4 address of the
multicast source requested.
Number of Groups(16 bits): indicates the number of group requested.
Reserved (16 bits): This field MUST be set to zero on transmission
and MUST be ignored on receipt.
IPv4 Multicast Group address [N](32 bits): contains IPv4 address of
the multicast group want to join or leave.
Auxliary Data(32 bits): contains functional data such as
authentication information.
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6.1.2. IPv6 multicast TLV
The format of the IPv6 Multicast TLV is shown in the following
figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=TBD3 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RD |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6 Multicast Source address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Groups(N) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6 Multicast Group address [1] |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
| . |
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6 Multicast Group address [N] |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Auxliary Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: IPv6 Multicast TLV Format
The type of the TLV is TBD.
RD(Route Distinguisher(8 bytes): indicates the VPN which the receiver
used.
IPv6 Multicast Source Address(16 bytes): contains IPv6 address of the
multicast source requested.
Number of Groups(16 bits): indicates the number of group requested.
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Reserved (16 bits): This field MUST be set to zero on transmission
and MUST be ignored on receipt.
IPv6 Multicast Group address [N](16 bytes): contains IPv6 address of
the multicast group want to join or leave.
Auxliary Data(32 bits): contains functional data such as
authentication information.
6.2. Multicast receiver information object
The MRI object is optional and specifies the access information of
receivers for matching the multicast registration information in
multicast access management. The MRI Objcet can be carried within a
PCReq message sent by the PCC to the PCE in muticast scenarios.
MRI Object-Class is TBD4. MRI Object-Type is 1.
The format of the MSR objcet body is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subdomain-id | BFR-ID | BSL |Flags|S|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: MRI Object Body Format
Subdomain-id(8 bits): Unique value identifying the BIER subdomain.
BFR-ID (16 bits): Identification of BFR in a subdomain.
BSL(BitString Length, 4 bits): encodes the length in bits of the
BitString as per[RFC8296] , the maximum length of the BitString is 7,
it indicates the length of BitString is 4096.It is used to refer to
the number of bits in the BitString.
Flags (3 bits): This field MUST be set to zero on transmission and
MUST be ignored on receipt.
S (Subscribe flag - 1 bit): The S flag set to 1 indicates that the
PCC delivers the message requesting to join the PCE. The S flag set
to 0 indicates that the PCC delivers the message requesting to leave
to the PCE.
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6.3. Forwarding indication object
The FI object is optional and used to indicate the path of multicast
data packets forwarding for headend in the form of BitString. The FI
Objcet can be carried within a PCUpd message sent by the PCE to the
PCC in muticast scenarios.
FI Object-Class is TBD5. BitString Object-Type is 1.
The format of the FI objcet body is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subdomain-id | SI | BSL | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (first 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
| . |
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BitString (last 32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: FI Object Body Format
Subdomain-id(8 bits): Unique value identifying the BIER subdomain.
SI (Set Identifier, 8 bits): encoding the Set Identifier used in the
encapsulation for this BIER subdomain for this BitString length..
BSL(BitString Length, 4 bits): encodes the length in bits of the
BitString as per[RFC8296] , the maximum length of the BitString is 7,
it indicates the length of BitString is 4096.It is used to refer to
the number of bits in the BitString.
Reserved (12 bits): This field MUST be set to zero on transmission
and MUST be ignored on receipt.
BitString(Variable length): indicates the path of multicast data
packets forwarding for headend.
7. Deployment Considerations
TBD
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8. Security Considerations
TBD
9. IANA Considerations
TBD
10. Contributor
TBD
11. Acknowledgement
TBD
12. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2362] Estrin, D., Farinacci, D., Helmy, A., Thaler, D., Deering,
S., Handley, M., Jacobson, V., Liu, C., Sharma, P., and L.
Wei, "Protocol Independent Multicast-Sparse Mode (PIM-SM):
Protocol Specification", RFC 2362, DOI 10.17487/RFC2362,
June 1998, <https://www.rfc-editor.org/info/rfc2362>.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>.
[RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
Encodings and Procedures for Multicast in MPLS/BGP IP
VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012,
<https://www.rfc-editor.org/info/rfc6514>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<https://www.rfc-editor.org/info/rfc8231>.
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[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>.
[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
for Bit Index Explicit Replication (BIER) in MPLS and Non-
MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
2018, <https://www.rfc-editor.org/info/rfc8296>.
Authors' Addresses
Huanan Li
China Telecom
Beiqijia Town, Changping District
Beijing, Beijing 102209
China
Email: lihn6@foxmail.com
Aijun Wang
China Telecom
Beiqijia Town, Changping District
Beijing, Beijing 102209
China
Email: wangaj3@chinatelecom.cn
Huaimo Chen
Futurewei
Boston
USA
Email: Huaimo.chen@futurewei.com
Chun Zhu
ZTE Corporation
50 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: zhu.chun1@zte.com.cn
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