SFC Y. Wei, Ed. Internet-Draft ZTE Corporation Intended status: Standards Track U. Elzur Expires: November 21, 2020 Intel S. Majee Caber systems inc May 20, 2020 Network Service Header Metadata Type 2 Variable-Length Context Headers draft-ietf-sfc-nsh-tlv-03 Abstract This draft describes Network Service Header (NSH) Metadata (MD) Type 2 variable-length context headers that can be used within a service function path. 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 https://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 November 21, 2020. Copyright Notice Copyright (c) 2020 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents 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 Wei, et al. Expires November 21, 2020 [Page 1] Internet-Draft NSH MD2 Context Headers May 2020 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. NSH MD Type 2 format . . . . . . . . . . . . . . . . . . . . 3 4. NSH MD Type 2 Context Headers . . . . . . . . . . . . . . . . 4 4.1. Forwarding Context . . . . . . . . . . . . . . . . . . . 4 4.2. Tenant Identifier . . . . . . . . . . . . . . . . . . . . 5 4.3. Content Type . . . . . . . . . . . . . . . . . . . . . . 5 4.4. Ingress Network Node Information . . . . . . . . . . . . 6 4.5. Ingress Network Source Interface . . . . . . . . . . . . 6 4.6. Flow ID . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.7. Source and/or Destination Groups . . . . . . . . . . . . 7 4.8. Universal Resource Identifier . . . . . . . . . . . . . . 7 4.9. Policy Identifier (POLICY_ID) . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7.1. Forwarding Context Types . . . . . . . . . . . . . . . . 9 7.2. Tenant Identifier Types . . . . . . . . . . . . . . . . . 9 7.3. Group Types . . . . . . . . . . . . . . . . . . . . . . . 10 7.4. URI Types . . . . . . . . . . . . . . . . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction Network Service Header (NSH) [RFC8300] is the Service Function Chaining (SFC) encapsulation required to support the SFC architecture. As such, NSH provides following key elements: 1. Service Function Path identification. 2. Indication of location within a Service Function Path. 3. Optional, per-packet metadata (fixed-length or variable). [RFC8300] further defines two metadata formats (MD Types): 1 and 2. MD Type 1 defines fixed length, 16 bytes-long metadata, whereas MD Type 2 defines a variable-length context format for metadata. This Wei, et al. Expires November 21, 2020 [Page 2] Internet-Draft NSH MD2 Context Headers May 2020 draft defines some common metadata contexts for use with NSH MD Type 2. This draft does not address metadata usage, updating/chaining of metadata or other SFP functions. Those topics are described in [RFC8300]. 2. Conventions used in this document 2.1. Terminology This document uses the terminology defined in the SFC Architecture [RFC7665]and the Network Service Header [RFC8300] 2.2. Requirements Language 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. 3. NSH MD Type 2 format A NSH is composed of a 4-byte Base Header, a 4-byte Service Path Header and Context Headers. The Base Header identifies the MD-Type in use: 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|O|U| TTL | Length |U|U|U|U|MD Type| Next Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: NSH Base Header Please refer to NSH [RFC8300] for a detailed header description. When the base header specifies MD Type = 0x2, zero or more Variable Length Context Headers MAY be added, immediately following the Service Path Header. Therefore, Length = 0x2 indicates that only the Base Header followed by the Service Path Header is present. The number, indicated in the Length field, of optional Variable Length Context Headers MUST be of an integer indicating length in 4-bytes words Figure 2 below depicts the format of the Context Header as defined in Section 2.5.1 of [RFC8300]. Wei, et al. Expires November 21, 2020 [Page 3] Internet-Draft NSH MD2 Context Headers May 2020 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class | Type |U| Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Variable-Length Metadata | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: NSH Variable-Length Context Headers 4. NSH MD Type 2 Context Headers In [RFC8300] defined that Metadata Class 0x0000 as IETF Base NSH MD Class. In this draft, metadata types are defined for the IETF Base NSH MD Class. 4.1. Forwarding Context This metadata context carries a network forwarding context, used for segregation and forwarding scope. Forwarding context can take several forms depending on the network environment. For example, VXLAN/VXLAN-GPE VNID, VRF identification or VLAN. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA1 |U| Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tenant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Forwarding Context where: Context Type (CT) is four bits-long field that defines the length and the interpretation of the Tenant ID field. Please see the IANA Considerations in Section 7. This document defines these CT values: 0x0 - 24 bits VXLAN/LISP virtual network identifier (VNI) 0x1 - 20 bits MPLS VPN label 0x2 - 12 bits VLAN identifier Wei, et al. Expires November 21, 2020 [Page 4] Internet-Draft NSH MD2 Context Headers May 2020 4.2. Tenant Identifier Tenant identification is often used for segregation within a multi- tenant environment. Orchestration system-generated tenant IDs are an example of such data. This context header carries both the format and value of the Tenant identifier. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = 0x02 |U| Length=12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tenant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tenant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Tenant Identifier List where: Tenant Type (TT) is four bits-long field that specifies the length of the Tenant ID field. This document defines the following values for TT: * 0x0 - 32 bits-long Tenant ID * 0x1 - 64 bits-long Tenant ID 4.3. Content Type Provides explicit information about the content being carried, for example, type of video or content value for billing purposes. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA3 |U| Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Content Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Content Type Wei, et al. Expires November 21, 2020 [Page 5] Internet-Draft NSH MD2 Context Headers May 2020 4.4. Ingress Network Node Information This context carries Node ID of the ingress network node. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA4 |U| Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Ingress Network Node ID 4.5. Ingress Network Source Interface This context carries the ingress interface of the ingress network node. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA5 |U| Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Interface/Port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Ingress Network Source Interface 4.6. Flow ID Flow ID provides a representation of the flow. Akin, but not identical to the usage described in [RFC6437]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA6 |U| Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flow ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: Flow ID Wei, et al. Expires November 21, 2020 [Page 6] Internet-Draft NSH MD2 Context Headers May 2020 4.7. Source and/or Destination Groups Intent-based systems can use this data to express the logical grouping of source and/or destination objects. [GROUPBASEDPOLICY] and [GROUPPOLICY] provide examples of such a system. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA7 |U| Length=12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | GT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Dest Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 9: End Point Group where: Group Type (GT) is four bits-long field that specifies the the interpretation of Source Group and/or Destination Group fields. This document defines the following values for GT: * 0x1 - Group Based Policy (GBP) end point group (EPG) 4.8. Universal Resource Identifier 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA8 |U| Length=var | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UT | URI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ URI ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: Universal Resource Identifier where URI (Universal Resource Identifier) Type is four bits-long field that specifies the format of the URI field. This document defines the following values for the URI Type field: Wei, et al. Expires November 21, 2020 [Page 7] Internet-Draft NSH MD2 Context Headers May 2020 * 0x1: URI in standard string format as defined in [RFC3986]. * 0x2: URI represented in a compacted hash format. 4.9. Policy Identifier (POLICY_ID) The policy is often referred by a system-generated identifier which is then used by the devices to lookup the content of the policy locally. For example, this identifier could be an index to an array, a lookup key, a database Id. The identifier allows enforcement agents or services to lookup up the content of their part of the policy quite efficiently. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metadata Class = 0x0000 | Type = TBA9 |U| Length=var | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | POLICY_ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ POLICY_ID ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: POLICY_ID 5. Security Considerations [RFC8300] describes the requisite security considerations for protecting NSH metadata. 6. Acknowledgments The authors would like to thank Paul Quinn, Behcet Sarikaya, Dirk von Hugo, Mohamed Boucadair, Carlos Pignataro and Gregory Mirsky for providing invaluable concepts and content for this document. 7. IANA Considerations This document requests IANA to assign the following types from the "NSH IETF- Assigned Optional Variable-Length Metadata Types" (0x0000 IETF Base NSH MD Class) registry available at [IANA-NSH-MD2] This document defines the following new values (Table 1)in the Network Service Header (NSH) metadata context Type registry: Wei, et al. Expires November 21, 2020 [Page 8] Internet-Draft NSH MD2 Context Headers May 2020 +-------+----------------------------------+---------------+ | Value | Description | Reference | +-------+----------------------------------+---------------+ | TBA1 | Forwarding Context | This document | | TBA2 | Tenant Identifier | This document | | TBA3 | Content Type | This document | | TBA4 | Ingress Network NodeID | This document | | TBA5 | Ingress Network Interface | This document | | TBA6 | Flow ID | This document | | TBA7 | Source and/or Destination Groups | This document | | TBA8 | Universal Resource Identifier | This document | | TBA9 | Policy Identifier | This document | +-------+----------------------------------+---------------+ Table 1: Type Values 7.1. Forwarding Context Types IANA is requested to create and maintain a new sub registry for "Forwarding Context" context types at [IANA-NSH-MD2]. +---------+-------------------------------------------+-------------+ | Value | Context Types | Reference | +---------+-------------------------------------------+-------------+ | 0x0 | 24-bits VXLAN/LISP virtual network | This | | | identifier (VNI) | document | | 0x1 | 20-bits MPLS VPN label | This | | | | document | | 0x2 | 12-bit VLAN identifier | This | | | | document | | 0x3-0x9 | Unassigned | IETF Review | | 0xA-0xE | Expert Review | IETF Review | | 0xF | Reserved | This | | | | document | +---------+-------------------------------------------+-------------+ Table 2: Fowarding Context Types 7.2. Tenant Identifier Types IANA is requested to create and maintain a new sub registry for "Tenant Identifier" context types at [IANA-NSH-MD2], with the following initial allocation: Wei, et al. Expires November 21, 2020 [Page 9] Internet-Draft NSH MD2 Context Headers May 2020 +-------+-------------------------+---------------+ | Value | Tenant Identifier Types | Reference | +-------+-------------------------+---------------+ | 0x0 | 32 bits-long Tenant ID | This document | | 0x1 | 64 bits-long Tenant ID | This document | +-------+-------------------------+---------------+ Table 3: Tenant Identifier Types 7.3. Group Types IANA is requested to create and maintain a new sub registry for "Group" context types at [IANA-NSH-MD2], with the following initial allocation: +---------+------------------------------------------+--------------+ | Value | Group Types | Reference | +---------+------------------------------------------+--------------+ | 0x0 | Reserved | This | | | | document | | 0x1 | Group Based Policy (GBP) end point group | This | | | (EPG) | document | | 0x2-0xE | Unassigned | IETF Review | | 0xF | Reserved | This | | | | document | +---------+------------------------------------------+--------------+ Table 4: Group Types 7.4. URI Types IANA is requested to create and maintain a new sub registry for "Group" context types at [IANA-NSH-MD2], with the following initial allocation: Wei, et al. Expires November 21, 2020 [Page 10] Internet-Draft NSH MD2 Context Headers May 2020 +---------+-------------------------------------------+-------------+ | Value | URI Types | Reference | +---------+-------------------------------------------+-------------+ | 0x0 | Reserved | This | | | | document | | 0x1 | URI in standard string format as defined | This | | | in [RFC3986] | document | | 0x2 | URI represented in a compacted hash | This | | | format | document | | 0x3-0xE | Unassigned | IETF Review | | 0xF | Reserved | This | | | | document | +---------+-------------------------------------------+-------------+ Table 5: URI Types 8. References 8.1. Normative References [IANA-NSH-MD2] IANA, "NSH IETF-Assigned Optional Variable-Length Metadata Types", . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, . [RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function Chaining (SFC) Architecture", RFC 7665, DOI 10.17487/RFC7665, October 2015, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8300] Quinn, P., Ed., Elzur, U., Ed., and C. Pignataro, Ed., "Network Service Header (NSH)", RFC 8300, DOI 10.17487/RFC8300, January 2018, . Wei, et al. Expires November 21, 2020 [Page 11] Internet-Draft NSH MD2 Context Headers May 2020 8.2. Informative References [GROUPBASEDPOLICY] OpenStack, "Group Based Policy", 2014. [GROUPPOLICY] OpenDaylight, "Group Policy", 2014. [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, "IPv6 Flow Label Specification", RFC 6437, DOI 10.17487/RFC6437, November 2011, . Authors' Addresses Yuehua (Corona) Wei (editor) ZTE Corporation No.50, Software Avenue Nanjing 210012 China Email: wei.yuehua@zte.com.cn Uri Elzur Intel Email: uri.elzur@intel.com Sumandra Majee Caber systems inc Email: Sum.majee@gmail.com Wei, et al. Expires November 21, 2020 [Page 12]