Network Service Header TLVs
draft-ietf-sfc-nsh-tlv-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 9263.
|
|
|---|---|---|---|
| Authors | Yuehua Wei , Paul Quinn , Uri Elzur , Sumandra Majee | ||
| Last updated | 2019-12-16 (Latest revision 2018-01-29) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 9263 (Proposed Standard) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-sfc-nsh-tlv-01
SFC Y. Wei, Ed.
Internet-Draft ZTE Corporation
Intended status: Standards Track P. Quinn
Expires: June 15, 2020 Cisco Systems, Inc.
U. Elzur
Intel
S. Majee
F5
December 13, 2019
Network Service Header TLVs
draft-ietf-sfc-nsh-tlv-01
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.
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This Internet-Draft will expire on June 15, 2020.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
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include Simplified BSD License text as described in Section 4.e of
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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. Requirements Language . . . . . . . . . . . . . . . . . . 3
3. NSH Type 2 Format . . . . . . . . . . . . . . . . . . . . . . 3
4. NSH Type 2 TLVs . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Forwarding Context . . . . . . . . . . . . . . . . . . . 4
4.2. Tenant . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.3. Content Type . . . . . . . . . . . . . . . . . . . . . . 5
4.4. Ingress Network Information . . . . . . . . . . . . . . . 5
4.5. Flow ID . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.6. Source and/or Destination Groups . . . . . . . . . . . . 6
4.7. Universal Resource Identifier (URI) . . . . . . . . . . . 6
4.8. Policy Identifier (POLICY_ID) . . . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 7
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 8
8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Network Service Header [RFC8300] is the SFC encapsulation protocol
used to create Service Function Chains. As such, NSH provides two
key elements:
1. Service Function Path identification
2. Metadata
NSH further defines two metadata formats (MD Types): 1 and 2. MD
Type 1 defines fixed length, 16 byte 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 NSH.
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2. Conventions used in this document
2.1. 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 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 are 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 the context header.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class |C| Type |R|R|R| Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Variable Metadata |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: NSH TLV Format
4. NSH Type 2 TLVs
As per NSH, TLV Class 0-7 are reserved for standards use. In this
draft we use TLV Class 0 for the following Types:
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type |R|R|R| Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Variable Metadata |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: NSH TLV Class=0x0
4.1. Forwarding Context
This TLV carries 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.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x1 |R|R|R| L=0x2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|CT (4)| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tentant ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Forwarding Context
Context Type (CT), 4 bits:
0x0: 24 bit VXLAN/LISP virtual network identifier (VNI)
0x1: 32 bit MPLS VPN label
0x2: VLAN
4.2. Tenant
Tenant identification is often used for segregation within a multi-
tenant environment. Orchestration system generated tenant IDs are an
example of such data.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x4 |R|R|R| L=0x3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|TT (4)| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tenant ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tenant ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Tenant Identifier
Tenant Type (TT), 4 bits:
0x0: 32 bit
0x1: 64 bit
4.3. Content Type
Provides explicit information about the content being carried, for
example, type of video or content value for billing purposes.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x6 |R|R|R| L=0x1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Content Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Content Type
4.4. Ingress Network Information
This data identifies ingress network node, and, if required, ingress
interface.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x7 |R|R|R| L=0x2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Node ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Interface/Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Ingress Network Info
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4.5. Flow ID
Flow ID provides a representation of flow. Akin, but not identical
to the usage described in [RFC6437].
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x8 |R|R|R| L=0x1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: 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.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0x9 |R|R|R| L=0x3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|GT(4) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Group |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Dest Group |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: End Point Group
Group type (4):
0x1: Group Based Policy (GBP) end point group (EPG)
4.7. Universal Resource Identifier (URI)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0xA |R|R|R| L=var |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|UT(4) | URI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ URI ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: Universal Resource Identifier
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URI type (4):
0x1: URI in standard string format as defined in [RFC3986].
0x2: URI represented in a compacted hash format.
4.8. Policy Identifier (POLICY_ID)
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.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV Class = 0x0 |C| Type=0xB |R|R|R| L=0x2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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 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. TLV types 0-127 are specified in this document. New
values are assigned via Standards Action [RFC8126].
8. References
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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,
<https://www.rfc-editor.org/info/rfc2119>.
[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,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8300] Quinn, P., Ed., Elzur, U., Ed., and C. Pignataro, Ed.,
"Network Service Header (NSH)", RFC 8300,
DOI 10.17487/RFC8300, January 2018,
<https://www.rfc-editor.org/info/rfc8300>.
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,
<https://www.rfc-editor.org/info/rfc6437>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
Authors' Addresses
Yuehua (Corona) Wei (editor)
ZTE Corporation
No.50, Software Avenue
Nanjing 210012
P. R. China
Email: wei.yuehua@zte.com.cn
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Paul Quinn
Cisco Systems, Inc.
Email: paulq@cisco.com
Uri Elzur
Intel
Email: uri.elzur@intel.com
Sumandra Majee
F5
Email: S.Majee@F5.com
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