< draft-zhang-bier-babel-extensions-01.txt		draft-zhang-bier-babel-extensions-02.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: December 29, 2017 Juniper Networks		Expires: May 6, 2020 Juniper Networks
	June 27, 2017		November 3, 2019
	BIER in BABEL		BIER in BABEL
	draft-zhang-bier-babel-extensions-01		draft-zhang-bier-babel-extensions-02
	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 32 ¶		skipping to change at page 1, line 32 ¶
	signaling information in Babel.		signaling information in Babel.
	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 December 29, 2017.		This Internet-Draft will expire on May 6, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2019 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
	(http://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. Advertisement of BIER information . . . . . . . . . . . . . . 2
	3.1. BIER BFR-prefix and BIER sub-TLV . . . . . . . . . . . . 3		3.1. BIER BFR-prefix and BIER sub-TLV . . . . . . . . . . . . 3
	3.1.1. BIER sub-TLV . . . . . . . . . . . . . . . . . . . . 3		3.1.1. BIER sub-TLV . . . . . . . . . . . . . . . . . . . . 3
	3.2. BIER MPLS Encapsulation sub-sub-TLV . . . . . . . . . . . 3		3.2. BIER MPLS Encapsulation sub-sub-TLV . . . . . . . . . . . 4
	3.3. Optional BIER sub-domain BSL conversion sub-sub-TLV . . . 4
	4. Tree types and tunneling . . . . . . . . . . . . . . . . . . 4		4. Tree types and tunneling . . . . . . . . . . . . . . . . . . 4
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 5		5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5		7. Normative References . . . . . . . . . . . . . . . . . . . . 5
	8. Normative References . . . . . . . . . . . . . . . . . . . . 5
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
	1. Introduction		1. Introduction
	[I-D.ietf-bier-architecture] introduces a novel multicast		[RFC8279] introduces a novel multicast architecture. It does not
	architecture. It does not require a signaling protocol to explicitly		require a signaling protocol to explicitly build multicast
	build multicast distribution trees, nor does it require intermediate		distribution trees, nor does it require intermediate nodes to
	nodes to maintain any per-flow state. All procedures necessary to		maintain any per-flow state. All procedures necessary to support
	support BIER are abbreviated by the "BIER architecture" moniker in		BIER are abbreviated by the "BIER architecture" moniker in this
	this document.		document.
	[RFC6126] and [I-D.ietf-babel-rfc6126bis] define a distance-vector		[I-D.ietf-babel-rfc6126bis] define a distance-vector routing protocol
	routing protocol under the name of "Babel". Babel operates in a		under the name of "Babel". Babel operates in a robust and efficient
	robust and efficient fashion both in ordinary wired as well as in		fashion both in ordinary wired as well as in wireless mesh networks.
	wireless mesh networks.
	2. Terminology		2. Terminology
	The terminology of this documents follows		The terminology of this documents follows [RFC8279], [RFC6126],
	[I-D.ietf-bier-architecture], [RFC6126], [RFC7557] and		[RFC7557] and [I-D.ietf-babel-rfc6126bis].
	[I-D.ietf-babel-rfc6126bis].
	3. Advertisement of BIER information		3. 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		3.1. 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
	skipping to change at page 3, line 19 ¶		skipping to change at page 3, line 19 ¶
	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		3.1.1. 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 [I-D.ietf-bier-isis-extensions] and		restrictions in [RFC8401] and [RFC8444]. It is a sub-TLV of Babel
	[I-D.ietf-bier-ospf-bier-extensions]. It is a sub-TLV of Babel
	update TLV. The prefix MUST NOT be summarized and the according sub-		update TLV. The prefix MUST NOT be summarized and the according sub-
	TLV MUST be treated as optional and transitive.		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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| sub-Type | Length |		| Type | Length |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| BAR | IPA | subdomain-id |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| BFR-id |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved | subdomain-id | BFR-id |		| sub-sub-TLVs (variable) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 1: BIER sub-TLV		Figure 1: BIER sub-TLV
	o Type: as indicated in IANA section.		o Type: as indicated in IANA section.
	o Length: 1 octet. Include the length of BIER sub-TLV and potential		o Length: 1 octet. Include the length of BIER sub-TLV and potential
	length of the two sub-sub-TLVs.		length of the sub-sub-TLVs.
	o Reserved: MUST be 0 on transmission, ignored on reception. May be		o BAR: BIER Algorithm. Specifies a BIER-specific algorithm used to
	used in future versions. 8 bits.		calculate underlay paths to reach BFERs. Values are allocated
			from the "BIER Algorithms" registry. 1 octet.
			o IPA: IGP Algorithm. Specifies an IGP Algorithm to either modify,
			enhance, or replace the calculation of underlay paths to reach
			BFERs as defined by the BAR value. Values are from the IGP
			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
	[I-D.ietf-bier-architecture]. If no BFR-id has been assigned this		[RFC8279]. If no BFR-id has been assigned this field is set to
	field is set to the invalid BFR-id.		the invalid BFR-id.
	3.2. BIER MPLS Encapsulation sub-sub-TLV		3.2. 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		TLV. The format and restrictions are aligned with [RFC8401] and
	[I-D.ietf-bier-isis-extensions] and		[RFC8444]. This sub-sub-TLV carries the information for the BIER
			MPLS encapsulation including the label range for a specific BSL for a
	[I-D.ietf-bier-ospf-bier-extensions]. This sub-sub-TLV carries the		certain <MT,SD> pair.
	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
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| sub-sub-Type | Length |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Lbl Range Size|BS Len | Label |		| Max SI |BS Len | Label |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 3: MPLS Encapsulation sub-sub-TLV		Figure 2: MPLS Encapsulation sub-sub-TLV
	o Type: value of 1 indicating MPLS encapsulation.		o Type: value of 1 indicating MPLS encapsulation.
	o Length: 1 octet		o Length: 1 octet
	o Local BitString Length (BS Len): Encoded bitstring length as per		o Max SI: Maximum Set Identifier (Section 1 of [RFC8279]) used in
	[I-D.ietf-bier-mpls-encapsulation]. 4 bits.		the encapsulation for this BIER subdomain for this BitString
			length, 1 octet. Each SI maps to a single label in the label
	o Label Range Size: Number of labels in the range for this BIER sub-		range. The first label is for SI=0, the second label is for SI=1,
	domain and bitstring length combination, 1 octet.		etc. If the label associated with the Maximum Set Identifier
			exceeds the 20-bit range, the sub-sub-TLV MUST be ignored.
	o Label: First label of the range, 20 bits. The labels are as
	defined in [I-D.ietf-bier-mpls-encapsulation].
	3.3. Optional BIER sub-domain BSL conversion sub-sub-TLV
	This sub-sub-TLV is used to carry the BSL information. Its		o Local BitString Length (BS Len): Encoded BitString length as per
	definition and restrictions are aligned with		[RFC8296]. 4 bits.
	[I-D.ietf-bier-isis-extensions].
	0 1 2 3		o Label: First label, 20 bits. The labels are as defined in
	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		[RFC8296].
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| sub-sub-Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 4: BSL conversion sub-sub-TLV
	4. Tree types and tunneling		4. 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
	skipping to change at page 5, line 18 ¶		skipping to change at page 5, line 14 ¶
	5. Security Considerations		5. Security Considerations
	TBD		TBD
	6. IANA Considerations		6. 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. Acknowledgements		7. Normative References
	The draft is aligned with the [I-D.ietf-bier-isis-extensions] and
	[I-D.ietf-bier-ospf-bier-extensions] as far as feasible.
	8. Normative References
	[I-D.ietf-babel-rfc6126bis]		[I-D.ietf-babel-rfc6126bis]
	Chroboczek, J., "The Babel Routing Protocol", draft-ietf-		Chroboczek, J. and D. Schinazi, "The Babel Routing
	babel-rfc6126bis-02 (work in progress), May 2017.		Protocol", draft-ietf-babel-rfc6126bis-15 (work in
			progress), October 2019.
	[I-D.ietf-bier-architecture]
	Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
	S. Aldrin, "Multicast using Bit Index Explicit
	Replication", draft-ietf-bier-architecture-07 (work in
	progress), June 2017.
	[I-D.ietf-bier-isis-extensions]
	Ginsberg, L., Przygienda, T., Aldrin, S., and Z. Zhang,
	"BIER support via ISIS", draft-ietf-bier-isis-
	extensions-04 (work in progress), March 2017.
	[I-D.ietf-bier-mpls-encapsulation]
	Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J.,
	Aldrin, S., and I. Meilik, "Encapsulation for Bit Index
	Explicit Replication in MPLS and non-MPLS Networks",
	draft-ietf-bier-mpls-encapsulation-07 (work in progress),
	June 2017.
	[I-D.ietf-bier-ospf-bier-extensions]
	Psenak, P., Kumar, N., Wijnands, I., Dolganow, A.,
	Przygienda, T., Zhang, Z., and S. Aldrin, "OSPF Extensions
	for BIER", draft-ietf-bier-ospf-bier-extensions-06 (work
	in progress), June 2017.
	[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,
	<http://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,
	<http://www.rfc-editor.org/info/rfc7557>.		<https://www.rfc-editor.org/info/rfc7557>.
			[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>.
			[RFC8401] Ginsberg, L., Ed., Przygienda, T., Aldrin, S., and Z.
			Zhang, "Bit Index Explicit Replication (BIER) Support via
			IS-IS", RFC 8401, DOI 10.17487/RFC8401, June 2018,
			<https://www.rfc-editor.org/info/rfc8401>.
			[RFC8444] Psenak, P., Ed., Kumar, N., Wijnands, IJ., Dolganow, A.,
			Przygienda, T., Zhang, J., and S. Aldrin, "OSPFv2
			Extensions for Bit Index Explicit Replication (BIER)",
			RFC 8444, DOI 10.17487/RFC8444, November 2018,
			<https://www.rfc-editor.org/info/rfc8444>.
	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
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