BIER WG Z. Zhang Internet-Draft ZTE Corporation Intended status: Standards Track A. Przygienda Expires: May 3, 2017 Juniper Networks October 30, 2016 BIER in BABEL draft-zhang-bier-babel-extensions-00 Abstract BIER introduces a novel architecture for multicast packet forwarding. It does not require a signalling protocol to explicitly build multicast distribution trees, nor does it require intermediate nodes to maintain any per-flow state. Babel defines a distance-vector routing protocol that operates in a robust and efficient fashion both in ordinary wired as well as in wireless mesh networks. This document defines a way to carry BIER information in Babel. 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 working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on May 3, 2017. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents Zhang & Przygienda Expires May 3, 2017 [Page 1] Internet-Draft BIER Babel extensions October 2016 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Advertisement of BIER information . . . . . . . . . . . . . . 3 3.1. BIER BFR-prefix and BIER sub-TLV . . . . . . . . . . . . 3 3.1.1. BIER sub-TLV . . . . . . . . . . . . . . . . . . . . 3 3.2. BIER MPLS Encapsulation sub-sub-TLV . . . . . . . . . . . 3 3.3. Optional BIER sub-domain BSL conversion sub-sub-TLV . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 6. Normative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction [I-D.ietf-bier-architecture] introduces a novel architecture for multicast data packets forwarding. It does not require a signalling protocol to explicitly build multicast distribution trees, nor does it require intermediate nodes to maintain any per-flow state. All the necessary extensions to perform this functionality are abbreviated by the "BIER architecture" moniker. BIER information can be carried in OSPF and ISIS routing protocol as defined in [I-D.ietf-bier-isis-extensions] and [I-D.ietf-bier-ospf-bier-extensions] respectively. The according tables for BIER forwarding purposes are built when OSPF/ISIS performs according calculations on the advertised information. [RFC6126] and [I-D.ietf-babel-rfc6126bis] define a distance-vector routing protocol under the name of "Babel". Babel operates in a robust and efficient fashion both in ordinary wired as well as in wireless mesh networks. 2. Terminology The terminology of this documents follows [I-D.ietf-bier-architecture], [RFC6126], [RFC7557] and [I-D.ietf-babel-rfc6126bis]. Zhang & Przygienda Expires May 3, 2017 [Page 2] Internet-Draft BIER Babel extensions October 2016 3. Advertisement of BIER information 3.1. BIER BFR-prefix and BIER sub-TLV BFR-prefix and according information is carried in a Babel Update TLV per [RFC6126]. Several new sub-TLVs and sub-sub-TLVs are defined to convey further BIER information such as BFR-id, sub-domain-id and BSL. 3.1.1. BIER sub-TLV The BIER sub-TLV format aligns exactly with the definition and restrictions in [I-D.ietf-bier-isis-extensions] and [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- TLV MUST be treated as optional and transitive. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | subdomain-id | BFR-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: BIER sub-TLV o Type: as indicated in IANA section. o Length: 1 octet o Reserved: MUST be 0 on transmission, ignored on reception. May be used in future versions. 8 bits. o subdomain-id: Unique value identifying the BIER sub-domain. 1 octet. 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 field is set to the invalid BFR-id. 3.2. BIER MPLS Encapsulation sub-sub-TLV The BIER MPLS Encapsulation sub-sub-TLV can be carried by BIER sub- TLV. The format and restrictions are aligned with [I-D.ietf-bier-isis-extensions] and [I-D.ietf-bier-ospf-bier-extensions]. This sub-sub-TLV carries the information for the BIER MPLS encapsulation including the label range for a specific BSL for a certain pair. Zhang & Przygienda Expires May 3, 2017 [Page 3] Internet-Draft BIER Babel extensions October 2016 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-sub-Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Lbl Range Size|BS Len | Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: MPLS Encapsulation sub-sub-TLV o Type: value of 1 indicating MPLS encapsulation. o Length: 1 octet o Local BitString Length (BS Len): Encoded bitstring length as per [I- D.draft-ietf-bier-mpls-encapsulation-05]. 4 bits. o Label Range Size: Number of labels in the range used on encapsulation for this BIER sub-domain for this bitstring length, 1 octet. 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 definition and restrictions are aligned with [I-D.ietf-bier-isis-extensions]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-sub-Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: BSL conversion sub-sub-TLV 4. Security Considerations TBD 5. Acknowledgements The draft is aligned with the [I-D.ietf-bier-isis-extensions] and [I-D.ietf-bier-ospf-bier-extensions] as far as feasible. Zhang & Przygienda Expires May 3, 2017 [Page 4] Internet-Draft BIER Babel extensions October 2016 6. Normative References [I-D.ietf-babel-rfc6126bis] Chroboczek, J., "The Babel Routing Protocol", draft-ietf- babel-rfc6126bis-00 (work in progress), August 2016. [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-05 (work in progress), October 2016. [I-D.ietf-bier-isis-extensions] Ginsberg, L., Przygienda, T., Aldrin, S., and Z. Zhang, "BIER support via ISIS", draft-ietf-bier-isis- extensions-03 (work in progress), September 2016. [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 Networks", draft-ietf-bier- mpls-encapsulation-05 (work in progress), July 2016. [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-04 (work in progress), September 2016. [I-D.pfister-bier-over-ipv6] Pfister, P. and I. Wijnands, "An IPv6 based BIER Routing Underlay", draft-pfister-bier-over-ipv6-00 (work in progress), September 2016. [RFC6126] Chroboczek, J., "The Babel Routing Protocol", RFC 6126, DOI 10.17487/RFC6126, April 2011, . [RFC7557] Chroboczek, J., "Extension Mechanism for the Babel Routing Protocol", RFC 7557, DOI 10.17487/RFC7557, May 2015, . Authors' Addresses Zhang & Przygienda Expires May 3, 2017 [Page 5] Internet-Draft BIER Babel extensions October 2016 Zheng(Sandy) Zhang ZTE Corporation No. 50 Software Ave, Yuhuatai Distinct Nanjing China Email: zhang.zheng@zte.com.cn Tony Przygienda Juniper Networks Email: prz@juniper.net Zhang & Przygienda Expires May 3, 2017 [Page 6]