SFC Y. Wei, Ed. Internet-Draft ZTE Corporation Intended status: Standards Track U. Elzur Expires: October 3, 2021 Intel S. Majee C. Pignataro Cisco April 1, 2021 Network Service Header Metadata Type 2 Variable-Length Context Headers draft-ietf-sfc-nsh-tlv-05 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 October 3, 2021. Copyright Notice Copyright (c) 2021 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 Wei, et al. Expires October 3, 2021 [Page 1] Internet-Draft NSH MD2 Context Headers April 2021 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. 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. Ingress Network Node Information . . . . . . . . . . . . 5 4.4. Ingress Network Source Interface . . . . . . . . . . . . 6 4.5. Flow ID . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.6. Source and/or Destination Groups . . . . . . . . . . . . 7 4.7. Universal Resource Identifier . . . . . . . . . . . . . . 8 4.8. Policy Identifier (POLICY_ID) . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7.1. Forwarding Context Types . . . . . . . . . . . . . . . . 10 7.2. Tenant Identifier Types . . . . . . . . . . . . . . . . . 10 7.3. Node ID Types . . . . . . . . . . . . . . . . . . . . . . 10 7.4. Group Types . . . . . . . . . . . . . . . . . . . . . . . 11 7.5. URI Types . . . . . . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 8.2. Informative References . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 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 the fixed-length, 16-octet long metadata, whereas MD Type 2 defines a variable-length context format for metadata. Wei, et al. Expires October 3, 2021 [Page 2] Internet-Draft NSH MD2 Context Headers April 2021 This 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 An NSH is composed of a 4-octet Base Header, a 4-octet 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 value of the Length field, of optional Variable Length Context Headers, MUST be an integer indicating the length in 4-octet words. Figure 2 below depicts the format of the Context Header as defined in Section 2.5.1 of [RFC8300]. Wei, et al. Expires October 3, 2021 [Page 3] Internet-Draft NSH MD2 Context Headers April 2021 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 October 3, 2021 [Page 4] Internet-Draft NSH MD2 Context Headers April 2021 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. Ingress Network Node Information This context header carries a Node ID of the ingress network node. Wei, et al. Expires October 3, 2021 [Page 5] Internet-Draft NSH MD2 Context Headers April 2021 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 = 20| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NIT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Ingress Network Node ID where: Node ID Type (NIT) is four bits-long field that specifies the length of the Node ID field. This document defines the following values for NIT: * 0x0 - 32 bits-long Node ID * 0x1 - 128 bits-long Node ID 4.4. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Interface/Port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Ingress Network Source Interface Wei, et al. Expires October 3, 2021 [Page 6] Internet-Draft NSH MD2 Context Headers April 2021 4.5. Flow ID Flow ID provides a field in the NSH MD Type 2 to label packets belonging to the same flow. Absence of this field, or a value of zero denotes that packets have not been labeled. [RFC6437] defined IPv6 Flow Label as a 20-bit long unsigned integer. Also, [RFC6790], which defined the use of an entropy label in the MPLS network, is 20-bit long. If either IPv6 Flow Label or MPLS entropy label (identified by preceding Entropy Label Indicator) are carried in the Flow ID field, it occupies 20 least significant bits in the 4-octet long word. 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 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 = TBA7 |U| Length=12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | GT | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Dest Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: End Point Group where: Wei, et al. Expires October 3, 2021 [Page 7] Internet-Draft NSH MD2 Context Headers April 2021 Group Type (GT) is four bits-long field that specifies the interpretation of Source Group and/or Destination Group fields. This document defines the following values for GT: * 0x1 - Group Based Policy (GBP) an end point group (EPG) 4.7. 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 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 to by a system-generated identifier, which is then used by the devices to look up the policy's content 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. Wei, et al. Expires October 3, 2021 [Page 8] Internet-Draft NSH MD2 Context Headers April 2021 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 10: 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, 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: +-------+----------------------------------+---------------+ | Value | Description | Reference | +-------+----------------------------------+---------------+ | TBA1 | Forwarding Context | This document | | TBA2 | Tenant Identifier | 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 Wei, et al. Expires October 3, 2021 [Page 9] Internet-Draft NSH MD2 Context Headers April 2021 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 document | | | identifier (VNI) | | | 0x1 | 20-bits MPLS VPN label | This document | | 0x2 | 12-bit VLAN identifier | This document | | 0x3-0xC | Unassigned | IETF Review | | 0xD-0xE | Unassigned | Experimental | | | | Use | | 0xF | Reserved | This document | +---------+-----------------------------------------+---------------+ Table 2: Forwarding 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: +-------+-------------------------+---------------+ | 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. Node ID Types IANA is requested to create and maintain a new sub-registry for "Node ID" context types at [IANA-NSH-MD2], with the following initial allocation: Wei, et al. Expires October 3, 2021 [Page 10] Internet-Draft NSH MD2 Context Headers April 2021 +-------+-----------------------+---------------+ | Value | Node ID Types | Reference | +-------+-----------------------+---------------+ | 0x0 | 32 bits-long Node ID | This document | | 0x1 | 128 bits-long Node ID | This document | +-------+-----------------------+---------------+ Table 4: Node ID Types 7.4. 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 documen | | | | t | | 0x1 | Group Based Policy (GBP) end point group | This documen | | | (EPG) | t | | 0x2-0xE | Unassigned | IETF Review | | 0xF | Reserved | This documen | | | | t | +---------+------------------------------------------+--------------+ Table 5: Group Types 7.5. 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 October 3, 2021 [Page 11] Internet-Draft NSH MD2 Context Headers April 2021 +---------+-------------------------------------------+-------------+ | Value | URI Types | Reference | +---------+-------------------------------------------+-------------+ | 0x0 | Reserved | This docume | | | | nt | | 0x1 | URI in standard string format as defined | This docume | | | in [RFC3986] | nt | | 0x2 | URI represented in a compacted hash | This docume | | | format | nt | | 0x3-0xE | Unassigned | IETF Review | | 0xF | Reserved | This docume | | | | nt | +---------+-------------------------------------------+-------------+ Table 6: 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 October 3, 2021 [Page 12] Internet-Draft NSH MD2 Context Headers April 2021 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, . [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and L. Yong, "The Use of Entropy Labels in MPLS Forwarding", RFC 6790, DOI 10.17487/RFC6790, November 2012, . 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 Email: Sum.majee@gmail.com Carlos Pignataro Cisco Email: cpignata@cisco.com Wei, et al. Expires October 3, 2021 [Page 13]