Network Working Group X. Xu Internet-Draft Huawei Intended status: Standards Track S. Somasundaram Expires: August 28, 2015 Alcatel-Lucent C. Jacquenet France Telecom R. Raszuk Mirantis Inc. February 24, 2015 BIER Encapsulation draft-xu-bier-encapsulation-02 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 August 28, 2015. Copyright Notice Copyright (c) 2015 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 August 28, 2015 [Page 1] Internet-Draft BIER Encapsulation February 2015 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 August 28, 2015 [Page 2] Internet-Draft BIER Encapsulation February 2015 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 |Res| SI | MT-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BFIR-ID | Sub-domain | Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Entropy | DS | TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BitString (first 32 bits) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ BitString (last 32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Ver(sion): a 4-bit field identifying the version of the BIER header. This document specifies version 0 of the BIER header. BS Length: a one-octet field indicating the length of the BitString in 4-byte. Note that legal BS Length values are specified in [I-D.wijnands-bier-architecture]. Res: a 2-bit reserved field. SI: a 10-bit field encoding the Set-Identifier (SI) for this packet. MT-ID: a one-octet field indicating which routing topology [RFC4915] [RFC5120] should be applied for BIER forwarding. BFIR-ID: a 2-octet field encoding the BFR-ID of the BFIR, in the sub-domain to which the packet has been assigned. Sub-domain: a one-octet field encoding the sub-domain to which the packet has been assigned. Protocol: a one-octet field indicating the protocol type of the BIER payload as per IP protocol numbers used in the Protocol field Xu, et al. Expires August 28, 2015 [Page 3] Internet-Draft BIER Encapsulation February 2015 of the IPv4 header and the Next Header field of IPv6 header. The valid BIER payload types include but not limited to IPv4, IPv6, MPLS, VXLAN [RFC7348],VXLAN-GPE [I-D.quinn-vxlan-gpe] , and etc. The corresponding IP Protocol numbers for VXLAN and VXLAN-GPE are to be allocated by IANA. Entropy: a 2-octet field containing an "entropy" value that can be used for load balancing purposes. BitString: a 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 field in the IPv4 or or the Next-Header field in the 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 (i.e., 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 IP Protocol numbers for VXLAN and VXLAN-GPE respectively. Xu, et al. Expires August 28, 2015 [Page 4] Internet-Draft BIER Encapsulation February 2015 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-04 (work in progress), February 2015. [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 August 28, 2015 [Page 5] Internet-Draft BIER Encapsulation February 2015 [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 August 28, 2015 [Page 6]