Network Working Group X. Xu Internet-Draft Huawei Intended status: Standards Track S. Somasundaram Expires: April 23, 2015 Alcatel-Lucent C. Jacquenet France Telecom R. Raszuk Mirantis Inc. October 20, 2014 BIER Encapsulation draft-xu-bier-encapsulation-01 Abstract Bit Index Explicit Replication (BIER) is a new multicast forwarding paradigm which doesn't require an explicit tree-building protocol and doesn't require intermediate routers to maintain any multicast state. This document proposes a transport-independent BIER encapsulation header which is applicable in any kind of transport networks. 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 April 23, 2015. Copyright Notice Copyright (c) 2014 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 Xu, et al. Expires April 23, 2015 [Page 1] Internet-Draft BIER Encapsulation October 2014 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 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. BIER Header . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Transport Encapsulation for BIER Header . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Security Considerations . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . 5 8.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction Bit Index Explicit Replication (BIER) [I-D.wijnands-bier-architecture] is a new multicast forwarding paradigm which doesn't require an explicit tree-building protocol and doesn't require intermediate routers to maintain any multicast state. As described in [I-D.wijnands-bier-architecture], BIER requires that a multicast data packet (e.g., an IP packet or an MPLS packet) to be encapsulated with a BIER header that carries the information needed for supporting the BIER forwarding procedures. This information at least includes Set-Identifier (SI), Multi-Topology Identifier (MT-ID) and BitString. The SI and the BitString are used together to identify the set of egress BFRs (BFERs) to which the packet must be delivered. In addition, to indicate what type of payload is following the BIER header, a protocol type field is neccessary. This document proposes a transport-independent BIER encapsulation header which is applicable in any kind of transport networks. 1.1. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Xu, et al. Expires April 23, 2015 [Page 2] Internet-Draft BIER Encapsulation October 2014 2. Terminology This memo makes use of the terms defined in [I-D.wijnands-bier-architecture]. 3. BIER Header The BIER header is shown as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ver | BS Length | SI | MT-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BFIR-ID | Protocol Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Entropy | DS | TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitString (first 32 bits) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ BitString (last 32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Ver(sion): This 4-bit field identifies the version of the BIER header. This document specifies version 0 of the BIER header. BS Length: This 8-bit field indicates the length of the BitString in 4-byte unit. In other words, if the BitString length is 4*n byte, this field should be filled with n (e.g., if the length of the BitString is 32 bits, the length field is set to 1, if the length of the BitString is 64 bits, the length field is set to 2...) SI: This 8-bit field is filled with the Set-Identifier (SI) for this packet. MT-ID: This 12-bit field indicates which routing topology [RFC4915] [RFC5120] should be applied for BIER forwarding. BFIR-ID: This 16-bit field is filled with the BFR-ID of the BFIR. Protocol Type: This 16-bit field indicates the protocol type of the BIER payload as per [ETYPES]. The BIER payload types include but not limited to IPv4 packet, IPv6 packet, MPLS packet, VXLAN packet [RFC7348] VXLAN-GPE packet [I-D.quinn-vxlan-gpe], etc. The Xu, et al. Expires April 23, 2015 [Page 3] Internet-Draft BIER Encapsulation October 2014 corresponding Ethertype codes for VXLAN and VXLAN-GPE are TBD1 and TBD2 respectively. Entropy: This 16-bit field specifies an "entropy" value that can be used for load balancing purposes. BitString: The variable-length BitString field that, together with the SI field, identifies all the destination BFERs for this packet. DS: The usage of this field is no different from that of the Differentiated Services (DS) field in the IPv4 or IPv6 headers [RFC2474]. TTL: The usage of this field is no different from that of the Time to Live (TTL) field in the IPv4 header. 4. Transport Encapsulation for BIER Header Since the BIER encapsulation format as specified in Section 3 is transport-independent, it can be encapsulated with any type of transport encapsulation headers, such as Ethernet header, PPP header, IP header, MPLS header, GRE header, UDP header etc. It requires for each possible transport encapsulation header to be able to indicate the payload is an BIER header. For instance, In the BIER-in-MAC encapsulation case, the EtherType field in the Ethernet header is used. In the BIER-in-IP encapsulation case, the Protocol or Next- Header field in the IPv4 or IPv6 header is used. In the BIER-in-MPLS encapsulation case, either the Protocol Type field [I-D.xu-mpls-payload-protocol-identifier] within the MPLS packet or a to-be-assigned Extended Spcial Purpose label [RFC7274] is used. 5. Acknowledgements TBD. 6. IANA Considerations This document includes a request to IANA to allocate an EtherType code,a PPP protocol code, an IPv4 protocol code, an IPv6 Next-Header code, a UDP destination port for carring the BIER-encapsulated packet over the corresponding transport networks. Furthermore, This document includes a request to IANA to allocate EtherType codes for VXLAN and VXLAN-GPE respectively. Xu, et al. Expires April 23, 2015 [Page 4] Internet-Draft BIER Encapsulation October 2014 7. Security Considerations TBD. 8. References 8.1. Normative References [ETYPES] The IEEE Registration Authority, "IEEE 802 Numbers", 2012. [I-D.wijnands-bier-architecture] Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and S. Aldrin, "Multicast using Bit Index Explicit Replication", draft-wijnands-bier-architecture-01 (work in progress), October 2014. [I-D.xu-mpls-payload-protocol-identifier] Xu, X. and M. Chen, "MPLS Payload Protocol Identifier", draft-xu-mpls-payload-protocol-identifier-00 (work in progress), September 2013. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC7274] Kompella, K., Andersson, L., and A. Farrel, "Allocating and Retiring Special-Purpose MPLS Labels", RFC 7274, June 2014. 8.2. Informative References [I-D.quinn-vxlan-gpe] Quinn, P., Agarwal, P., Fernando, R., Lewis, D., Kreeger, L., Smith, M., Yadav, N., Yong, L., Xu, X., Elzur, U., and P. Garg, "Generic Protocol Extension for VXLAN", draft- quinn-vxlan-gpe-03 (work in progress), July 2014. [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998. [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", RFC 4915, June 2007. [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi Topology (MT) Routing in Intermediate System to Intermediate Systems (IS-ISs)", RFC 5120, February 2008. Xu, et al. Expires April 23, 2015 [Page 5] Internet-Draft BIER Encapsulation October 2014 [RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, L., Sridhar, T., Bursell, M., and C. Wright, "Virtual eXtensible Local Area Network (VXLAN): A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks", RFC 7348, August 2014. Authors' Addresses Xiaohu Xu Huawei Email: xuxiaohu@huawei.com S Somasundaram Alcatel-Lucent Email: somasundaram.s@alcatel-lucent.com Christian Jacquenet France Telecom Email: christian.jacquenet@orange.com Robert Raszuk Mirantis Inc. Email: robert@raszuk.net Xu, et al. Expires April 23, 2015 [Page 6]