SFC Y. Wei, Ed. Internet-Draft ZTE Corporation Intended status: Standards Track U. Elzur Expires: September 4, 2020 Intel S. Majee Caber systems inc March 3, 2020 Network Service Header TLVs draft-ietf-sfc-nsh-tlv-02 Abstract This draft describes Network Service Header (NSH) MD-Type 2 metadata TLVs 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 September 4, 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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Wei, et al. Expires September 4, 2020 [Page 1] Internet-Draft Network Service Header TLVs March 2020 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 2 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. NSH Type 2 Format . . . . . . . . . . . . . . . . . . . . . . 3 4. NSH Type 2 TLVs . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Forwarding Context . . . . . . . . . . . . . . . . . . . 4 4.2. Tenant Identifier . . . . . . . . . . . . . . . . . . . . 5 4.3. Content Type . . . . . . . . . . . . . . . . . . . . . . 6 4.4. Ingress Network Information . . . . . . . . . . . . . . . 6 4.5. Flow ID . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.6. Source and/or Destination Groups . . . . . . . . . . . . 7 4.7. Universal Resource Identifier . . . . . . . . . . . . . . 7 4.8. Policy Identifier (POLICY_ID) . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . 10 8.2. Informative References . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction Network Service Header (NSH) [RFC8300] is the Service Function Chaining (SFC) encapsulation protocol used to create Service Function Chains. As such, NSH provides two key elements: 1. Service Function Path identification 2. Metadata [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 TLV format for metadata. This draft defines some common TLVs 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 Wei, et al. Expires September 4, 2020 [Page 2] Internet-Draft Network Service Header TLVs March 2020 2.1. Terminology NSH: Network Service Header MD Type: Metadata Format CT: Context Type TT: Tenant Type URI: Universal Resource Identifier SFC: Service Function Chaining 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 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|C|R|R|R|R|R|R| Length | 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 September 4, 2020 [Page 3] Internet-Draft Network Service Header TLVs March 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 TLV Format where Metadata Class (MD Class): Defines the scope of the Type field to provide a hierarchical namespace. Type - Indicates the explicit type of metadata being carried. The value is one from the Network Service Header (NSH) TLV Type registry (Section 7). Unassigned bit: One unassigned bit is available for future use. This bit MUST NOT be set, and it MUST be ignored on receipt. Length: Indicates the length of the variable-length metadata, in bytes. In case the metadata length is not an integer number of 4-byte words, the sender MUST add pad bytes immediately following the last metadata byte to extend the metadata to an integer number of 4-byte words. The receiver MUST round the Length field up to the nearest 4-byte-word boundary, to locate and process the next field in the packet. The receiver MUST access only those bytes in the metadata indicated by the Length field (i.e., actual number of bytes) and MUST ignore the remaining bytes up to the nearest 4- byte-word boundary. The length may be 0 or greater. A value of 0 denotes a Context Header without a Variable-Length Metadata field. 4. NSH Type 2 TLVs 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 TLV carries a network-centric forwarding context, used for segregation and forwarding scope. Forwarding context can take several forms depending on the network environment. Commonly used data includes VXLAN/VXLAN- GPE VNID, VRF identification or VLAN. Wei, et al. Expires September 4, 2020 [Page 4] Internet-Draft Network Service Header TLVs March 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 = 0x0000 | Type = 0x01 |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. This document defines these CT values: 0x0 - 24 bits-long VXLAN/LISP virtual network identifier (VNI) 0x1 - 32 bits-long MPLS VPN label 0x2 - VLAN 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. 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: Wei, et al. Expires September 4, 2020 [Page 5] Internet-Draft Network Service Header TLVs March 2020 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 = 0x03 |U| Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Content Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Content Type 4.4. Ingress Network Information This data identifies the ingress network node, and, if required, ingress interface. 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 = 0x04 |U| Length = 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Interface/Port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Ingress Network Information 4.5. Flow ID Flow ID provides a representation of the flow. Akin, but not identical to the usage described in [RFC6437]. Wei, et al. Expires September 4, 2020 [Page 6] Internet-Draft Network Service Header TLVs March 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 = 0x0000 | Type = 0x05 |U| Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flow ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Flow ID 4.6. 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 = 0x06 |U| Length=12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | GT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Dest Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: 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) 4.7. Universal Resource Identifier Wei, et al. Expires September 4, 2020 [Page 7] Internet-Draft Network Service Header TLVs March 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 = 0x0000 | Type = 0x07 |U| Length=var | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | UT | URI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ URI ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 9: 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: * 0x1: URI in standard string format as defined in [RFC3986]. * 0x2: URI represented in a compacted hash format. 4.8. 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 = 0x08 |U| Length=var | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | POLICY_ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ POLICY_ID ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: POLICY_ID 5. Security Considerations [RFC8300] describes the requisite security considerations for protecting NSH metadata. Wei, et al. Expires September 4, 2020 [Page 8] Internet-Draft Network Service Header TLVs March 2020 6. Acknowledgments The authors would like to thank Paul Quinn for contributing to the draft and thank Behcet Sarikaya, Dirk von Hugo and Mohamed Boucadair for their work regarding usage of subscriber and host information TLVs. 7. IANA Considerations IANA is requested to create a new "Network Service Header (NSH) TLV Type" registry according to Table 1. +-----------+--------------+-------------------------+ | Value | Description | Reference | +-----------+--------------+-------------------------+ | 0 | Reserved | This document | | 1- 127 | Unassigned | IETF Review | | 128 - 239 | Unassigned | First Come First Served | | 240 - 249 | Experimental | This document | | 250 - 254 | Private Use | This document | | 255 | Reserved | This document | +-----------+--------------+-------------------------+ Table 1: Network Service Header (NSH) TLV Type This document defines the following new values (Table 2) in the Network Service Header (NSH) TLV Type registry: +-------+----------------------------------+---------------+ | Value | Description | Reference | +-------+----------------------------------+---------------+ | 1 | Forwarding Context | This document | | 2 | Tenant Identifier | This document | | 3 | Content Type | This document | | 4 | Ingress Network Information | This document | | 5 | Flow ID | This document | | 6 | Source and/or Destination Groups | This document | | 7 | Universal Resource Identifier | This document | | 8 | Policy Identifier | This document | +-------+----------------------------------+---------------+ Table 2: Type Values 8. References Wei, et al. Expires September 4, 2020 [Page 9] Internet-Draft Network Service Header TLVs March 2020 8.1. Normative References [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, . [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, . 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 Wei, et al. Expires September 4, 2020 [Page 10] Internet-Draft Network Service Header TLVs March 2020 Uri Elzur Intel Email: uri.elzur@intel.com Sumandra Majee Caber systems inc Email: Sum.majee@gmail.com Wei, et al. Expires September 4, 2020 [Page 11]