< draft-zhang-bier-babel-extensions-02.txt		draft-zhang-bier-babel-extensions-03.txt >
	BIER WG Z. Zhang		BIER WG Z. Zhang
	Internet-Draft ZTE Corporation		Internet-Draft ZTE Corporation
	Intended status: Standards Track A. Przygienda		Intended status: Standards Track A. Przygienda
	Expires: May 6, 2020 Juniper Networks		Expires: November 18, 2020 Juniper Networks
	November 3, 2019		May 17, 2020
	BIER in BABEL		BIER in BABEL
	draft-zhang-bier-babel-extensions-02		draft-zhang-bier-babel-extensions-03
	Abstract		Abstract
	BIER introduces a novel multicast architecture. It does not require		BIER introduces a novel multicast architecture. It does not require
	a signaling protocol to explicitly build multicast distribution		a signaling protocol to explicitly build multicast distribution
	trees, nor does it require intermediate nodes to maintain any per-		trees, nor does it require intermediate nodes to maintain any per-
	flow state.		flow state.
	Babel defines a distance-vector routing protocol that operates in a		Babel defines a distance-vector routing protocol that operates in a
	robust and efficient fashion both in wired as well as in wireless		robust and efficient fashion both in wired as well as in wireless
	skipping to change at page 1, line 39 ¶		skipping to change at page 1, line 39 ¶
	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 https://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 May 6, 2020.		This Internet-Draft will expire on November 18, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2020 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
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	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. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
	3. Advertisement of BIER information . . . . . . . . . . . . . . 2		3. Conventions Used in This Document . . . . . . . . . . . . . . 2
	3.1. BIER BFR-prefix and BIER sub-TLV . . . . . . . . . . . . 3		4. Advertisement of BIER information . . . . . . . . . . . . . . 3
	3.1.1. BIER sub-TLV . . . . . . . . . . . . . . . . . . . . 3		4.1. BIER BFR-prefix and BIER sub-TLV . . . . . . . . . . . . 3
	3.2. BIER MPLS Encapsulation sub-sub-TLV . . . . . . . . . . . 4		4.1.1. BIER sub-TLV . . . . . . . . . . . . . . . . . . . . 3
	4. Tree types and tunneling . . . . . . . . . . . . . . . . . . 4		4.2. BIER MPLS Encapsulation sub-sub-TLV . . . . . . . . . . . 4
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 5		4.3. BIER non-MPLS Encapsulation sub-sub-TLV . . . . . . . . . 5
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5		4.3.1. BIER IPv6 transportation sub-sub-TLV . . . . . . . . 5
	7. Normative References . . . . . . . . . . . . . . . . . . . . 5		5. Tree types and tunneling . . . . . . . . . . . . . . . . . . 6
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6		6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
			7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
			8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
			8.1. Normative References . . . . . . . . . . . . . . . . . . 6
			8.2. Informative References . . . . . . . . . . . . . . . . . 7
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
	1. Introduction		1. Introduction
	[RFC8279] introduces a novel multicast architecture. It does not		[RFC8279] introduces a novel multicast architecture. It does not
	require a signaling protocol to explicitly build multicast		require a signaling protocol to explicitly build multicast
	distribution trees, nor does it require intermediate nodes to		distribution trees, nor does it require intermediate nodes to
	maintain any per-flow state. All procedures necessary to support		maintain any per-flow state. All procedures necessary to support
	BIER are abbreviated by the "BIER architecture" moniker in this		BIER are abbreviated by the "BIER architecture" moniker in this
	document.		document.
	[I-D.ietf-babel-rfc6126bis] define a distance-vector routing protocol		[I-D.ietf-babel-rfc6126bis] define a distance-vector routing protocol
	under the name of "Babel". Babel operates in a robust and efficient		under the name of "Babel". Babel operates in a robust and efficient
	fashion both in ordinary wired as well as in wireless mesh networks.		fashion both in ordinary wired as well as in wireless mesh networks.
	2. Terminology		2. Terminology
	The terminology of this documents follows [RFC8279], [RFC6126],		The terminology of this documents follows [RFC8279], [RFC6126],
	[RFC7557] and [I-D.ietf-babel-rfc6126bis].		[RFC7557] and [I-D.ietf-babel-rfc6126bis].
	3. Advertisement of BIER information		3. 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.
			4. Advertisement of BIER information
	In case a router is configured with BIER information, and Babel is		In case a router is configured with BIER information, and Babel is
	the routing protocol used, such a router MAY use Babel protocol to		the routing protocol used, such a router MAY use Babel protocol to
	announce the BIER information using the BIER sub-TLV specified below.		announce the BIER information using the BIER sub-TLV specified below.
	3.1. BIER BFR-prefix and BIER sub-TLV		4.1. BIER BFR-prefix and BIER sub-TLV
	BFR-prefix and according information is carried in a Babel Update TLV		BFR-prefix and according information is carried in a Babel Update TLV
	per [I-D.ietf-babel-rfc6126bis]. A new sub-TLV is defined to convey		per [I-D.ietf-babel-rfc6126bis]. A new sub-TLV is defined to convey
	further BIER information such as BFR-id, sub-domain-id and BSL. Two		further BIER information such as BFR-id, sub-domain-id and BSL. Two
	sub-sub-TLVs are carried as payload of BIER sub-TLV.		sub-sub-TLVs are carried as payload of BIER sub-TLV.
	The mandatory bit of BIER sub-TLV should be set to 0. If a router		The mandatory bit of BIER sub-TLV should be set to 0. If a router
	cannot recognize a sub-TLV, the router MUST ignore this unknown sub-		cannot recognize a sub-TLV, the router MUST ignore this unknown sub-
	TLV.		TLV.
	3.1.1. BIER sub-TLV		4.1.1. BIER sub-TLV
	The BIER sub-TLV format aligns exactly with the definition and		The BIER sub-TLV format aligns exactly with the definition and
	restrictions in [RFC8401] and [RFC8444]. It is a sub-TLV of Babel		restrictions in [RFC8401] , [RFC8444] and
	update TLV. The prefix MUST NOT be summarized and the according sub-		[I-D.ietf-bier-ospfv3-extensions]. It is a sub-TLV of Babel update
	TLV MUST be treated as optional and transitive.		TLV. The prefix MUST NOT be summarized and the according sub-TLV
			MUST be treated as optional and transitive.
	0 1 2 3		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 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 | Length |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| BAR | IPA | subdomain-id |		| BAR | IPA | subdomain-id |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| BFR-id |		| BFR-id |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	skipping to change at page 4, line 9 ¶		skipping to change at page 4, line 21 ¶
	BFERs as defined by the BAR value. Values are from the IGP		BFERs as defined by the BAR value. Values are from the IGP
	Algorithm registry. 1 octet.		Algorithm registry. 1 octet.
	o subdomain-id: Unique value identifying the BIER sub-domain. 1		o subdomain-id: Unique value identifying the BIER sub-domain. 1
	octet.		octet.
	o BFR-id: A 2 octet field encoding the BFR-id, as documented in		o BFR-id: A 2 octet field encoding the BFR-id, as documented in
	[RFC8279]. If no BFR-id has been assigned this field is set to		[RFC8279]. If no BFR-id has been assigned this field is set to
	the invalid BFR-id.		the invalid BFR-id.
	3.2. BIER MPLS Encapsulation sub-sub-TLV		4.2. BIER MPLS Encapsulation sub-sub-TLV
	The BIER MPLS Encapsulation sub-sub-TLV can be carried by BIER sub-		The BIER MPLS Encapsulation sub-sub-TLV can be carried by BIER sub-
	TLV. The format and restrictions are aligned with [RFC8401] and		TLV. The format and restrictions are aligned with [RFC8401],
	[RFC8444]. This sub-sub-TLV carries the information for the BIER		[RFC8444] and [I-D.ietf-bier-ospfv3-extensions]. This sub-sub-TLV
	MPLS encapsulation including the label range for a specific BSL for a		carries the information for the BIER MPLS encapsulation including the
	certain <MT,SD> pair.		label range for a specific BSL for a certain <MT,SD> pair.
	0 1 2 3		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 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 | Length |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Max SI |BS Len | Label |		| Max SI |BS Len | Label |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 2: MPLS Encapsulation sub-sub-TLV		Figure 2: MPLS Encapsulation sub-sub-TLV
	skipping to change at page 4, line 43 ¶		skipping to change at page 5, line 8 ¶
	range. The first label is for SI=0, the second label is for SI=1,		range. The first label is for SI=0, the second label is for SI=1,
	etc. If the label associated with the Maximum Set Identifier		etc. If the label associated with the Maximum Set Identifier
	exceeds the 20-bit range, the sub-sub-TLV MUST be ignored.		exceeds the 20-bit range, the sub-sub-TLV MUST be ignored.
	o Local BitString Length (BS Len): Encoded BitString length as per		o Local BitString Length (BS Len): Encoded BitString length as per
	[RFC8296]. 4 bits.		[RFC8296]. 4 bits.
	o Label: First label, 20 bits. The labels are as defined in		o Label: First label, 20 bits. The labels are as defined in
	[RFC8296].		[RFC8296].
	4. Tree types and tunneling		4.3. BIER non-MPLS Encapsulation sub-sub-TLV
			The BIER non-MPLS Encapsulation sub-sub-TLV can be carried by BIER
			sub-TLV. The format and restrictions are aligned with
			[I-D.ietf-bier-lsr-ethernet-extensions]. This sub-sub-TLV carries
			the information for the BIER MPLS encapsulation including the label
			range for a specific BSL for a certain <MT,SD> pair.
			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 | Length |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Max SI | BIFT-id |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			|BS Len | Reserved |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			Figure 3: non-MPLS Encapsulation sub-sub-TLV
			o Type: value of 2 indicating non-MPLS encapsulation.
			o Length: 1 octet
			o Max SI: Maximum Set Identifier (Section 1 of [RFC8279]) used in
			the encapsulation for this BIER subdomain for this BitString
			length, 1 octet. The first BIFT-id is for SI=0, the second BIFT-
			id is for SI=1, etc. If the BIFT-id associated with the Maximum
			Set Identifier exceeds the 20-bit range, the sub-sub-TLV MUST be
			ignored.
			o BIFT-id: A 3-octet field, where the 20 rightmost bits represent
			the first BIFT-id in the BIFT-id range. The 4 leftmost bits MUST
			be ignored. The "BIFT-id range" is the set of 20-bit values
			beginning with the BIFT-id and ending with (BIFT-id + (Max SI)).
			These BIFT-id's are used for BIER forwarding as described in
			[RFC8279] and [RFC8296].
			o Local BitString Length (BS Len): Encoded BitString length as per
			[RFC8296]. 4 bits.
			4.3.1. BIER IPv6 transportation sub-sub-TLV
			The BIER IPv6 transportation sub-sub-TLV can be carried by BIER non-
			MPLS Encapsulation sub-sub-TLV. The format and restrictions are
			aligned with [I-D.zhang-bier-bierin6]. A node that requires IPv6
			encapsualtion MUST advertise the BIER IPv6 transportation sub-sub-TLV
			according to local configuration or policy in the BIER domain to
			request other BFRs to always use IPv6 encapsulation.
			The format is the same with the definition in section 4.1,
			[I-D.zhang-bier-bierin6].
			5. Tree types and tunneling
	Since Babel is performing a diffusion computation, support for		Since Babel is performing a diffusion computation, support for
	different tree types is not as natural as with link-state protocols.		different tree types is not as natural as with link-state protocols.
	Hence this specification is assuming that normal Babel reachability		Hence this specification is assuming that normal Babel reachability
	computation is performed without further modifications.		computation is performed without further modifications.
	BIER architecture does not rely on all routers in a domain performing		BIER architecture does not rely on all routers in a domain performing
	BFR procedures. How to support tunnels that will allow to tunnel		BFR procedures. How to support tunnels that will allow to tunnel
	BIER across such routers in Babel is for further study.		BIER across such routers in Babel is for further study.
	5. Security Considerations		6. Security Considerations
	TBD		TBD
	6. IANA Considerations		7. IANA Considerations
	A new type of Babel update sub-TLV needs to be defined for BIER		A new type of Babel update sub-TLV needs to be defined for BIER
	information advertisement.		information advertisement.
	7. Normative References		8. References
			8.1. Normative References
	[I-D.ietf-babel-rfc6126bis]		[I-D.ietf-babel-rfc6126bis]
	Chroboczek, J. and D. Schinazi, "The Babel Routing		Chroboczek, J. and D. Schinazi, "The Babel Routing
	Protocol", draft-ietf-babel-rfc6126bis-15 (work in		Protocol", draft-ietf-babel-rfc6126bis-17 (work in
	progress), October 2019.		progress), February 2020.
			[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>.
	[RFC6126] Chroboczek, J., "The Babel Routing Protocol", RFC 6126,		[RFC6126] Chroboczek, J., "The Babel Routing Protocol", RFC 6126,
	DOI 10.17487/RFC6126, April 2011,		DOI 10.17487/RFC6126, April 2011,
	<https://www.rfc-editor.org/info/rfc6126>.		<https://www.rfc-editor.org/info/rfc6126>.
	[RFC7557] Chroboczek, J., "Extension Mechanism for the Babel Routing		[RFC7557] Chroboczek, J., "Extension Mechanism for the Babel Routing
	Protocol", RFC 7557, DOI 10.17487/RFC7557, May 2015,		Protocol", RFC 7557, DOI 10.17487/RFC7557, May 2015,
	<https://www.rfc-editor.org/info/rfc7557>.		<https://www.rfc-editor.org/info/rfc7557>.
			[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>.
	[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,		[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
	Przygienda, T., and S. Aldrin, "Multicast Using Bit Index		Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
	Explicit Replication (BIER)", RFC 8279,		Explicit Replication (BIER)", RFC 8279,
	DOI 10.17487/RFC8279, November 2017,		DOI 10.17487/RFC8279, November 2017,
	<https://www.rfc-editor.org/info/rfc8279>.		<https://www.rfc-editor.org/info/rfc8279>.
	[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,		[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
	Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation		Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
	for Bit Index Explicit Replication (BIER) in MPLS and Non-		for Bit Index Explicit Replication (BIER) in MPLS and Non-
	MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January		MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
	skipping to change at page 6, line 5 ¶		skipping to change at page 7, line 32 ¶
	Zhang, "Bit Index Explicit Replication (BIER) Support via		Zhang, "Bit Index Explicit Replication (BIER) Support via
	IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018,		IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018,
	<https://www.rfc-editor.org/info/rfc8401>.		<https://www.rfc-editor.org/info/rfc8401>.
	[RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A.,		[RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A.,
	Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2		Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2
	Extensions for Bit Index Explicit Replication (BIER)",		Extensions for Bit Index Explicit Replication (BIER)",
	RFC 8444, DOI 10.17487/RFC8444, November 2018,		RFC 8444, DOI 10.17487/RFC8444, November 2018,
	<https://www.rfc-editor.org/info/rfc8444>.		<https://www.rfc-editor.org/info/rfc8444>.
			8.2. Informative References
			[I-D.ietf-bier-lsr-ethernet-extensions]
			Dhanaraj, S., Wijnands, I., Psenak, P., Zhang, Z., Yan,
			G., and J. Xie, "LSR Extensions for BIER over Ethernet",
			draft-ietf-bier-lsr-ethernet-extensions-01 (work in
			progress), July 2019.
			[I-D.ietf-bier-ospfv3-extensions]
			Psenak, P., Kumar, N., and I. Wijnands, "OSPFv3 Extensions
			for BIER", draft-ietf-bier-ospfv3-extensions-01 (work in
			progress), November 2019.
			[I-D.zhang-bier-bierin6]
			Zhang, Z., Przygienda, T., Wijnands, I., Bidgoli, H., and
			M. McBride, "BIER in IPv6 (BIERin6)", draft-zhang-bier-
			bierin6-04 (work in progress), January 2020.
	Authors' Addresses		Authors' Addresses
	Zheng(Sandy) Zhang		Zheng(Sandy) Zhang
	ZTE Corporation		ZTE Corporation
	No. 50 Software Ave, Yuhuatai Distinct		No. 50 Software Ave, Yuhuatai Distinct
	Nanjing		Nanjing
	China		China
	Email: zhang.zheng@zte.com.cn		Email: zhang.zheng@zte.com.cn
End of changes. 18 change blocks.
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