Carrying Virtual Transport Network Identifier in IPv6 Extension Header
draft-dong-6man-enhanced-vpn-vtn-id-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Authors | Jie Dong , Zhenbin Li , Chongfeng Xie , Chenhao Ma | ||
| Last updated | 2020-07-13 | ||
| Replaced by | draft-ietf-6man-enhanced-vpn-vtn-id, draft-ietf-6man-enhanced-vpn-vtn-id, draft-ietf-6man-enhanced-vpn-vtn-id | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-dong-6man-enhanced-vpn-vtn-id-01
Network Working Group J. Dong
Internet-Draft Z. Li
Intended status: Standards Track Huawei Technologies
Expires: January 14, 2021 C. Xie
C. Ma
China Telecom
July 13, 2020
Carrying Virtual Transport Network Identifier in IPv6 Extension Header
draft-dong-6man-enhanced-vpn-vtn-id-01
Abstract
This document proposes a new option type to carry virtual transport
network identifier (VTN ID) in the IPv6 extensions headers to
identify the Virtual Transport Network (VTN) the packet belongs to.
The procedure of processing the VTN option is also specified. This
provides a scalable solution for data plane encapsulation of enhanced
VPN (VPN+) as described in I-D.ietf-teas-enhanced-vpn. One typical
use case of VPN+ is to provide transport network slicing in 5G, while
it could also be used in more general cases.
Status of This Memo
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This Internet-Draft will expire on January 14, 2021.
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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. New IPv6 Extension Header Option for VTN . . . . . . . . . . 3
4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. VTN Option Insertion . . . . . . . . . . . . . . . . . . 4
4.2. VTN based Packet Forwarding . . . . . . . . . . . . . . . 4
5. Operational Considerations . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 5
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 5
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
10.1. Normative References . . . . . . . . . . . . . . . . . . 6
10.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Virtual private networks (VPNs) have served the industry well as a
means of providing different groups of users with logically isolated
connectivity over a common network. Some customers may request a
connectivity services with advanced characteristics such as complete
isolation from other services or guaranteed performance. These
services are "enhanced VPNs" (known as VPN+).
[I-D.ietf-teas-enhanced-vpn] describes the framework and candidate
component technologies for providing enhanced VPN services. One
typical use case of VPN+ is to provide transport network slicing in
5G, while it could also be used in more general cases.
The enhanced properties of VPN+ require tighter coordination and
integration between the underlay network resources and the overlay
network. VPN+ service is built on a Virtual Transport Network (VTN)
which has a customized network topology and a set of dedicated or
shared network resources allocated from the underlay network. The
overlay VPN together with the corresponding VTN in the underlay
provide the VPN+ service. In the network, traffic of different VPN+
services need to be processed separately based on the topology and
the network resources associated with the corresponding VTN.
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[I-D.dong-teas-enhanced-vpn-vtn-scalability] describes the
scalability considerations of enhanced VPN, in which one approach to
improve the data plane scalability is to introduce a dedicated
identifier indata packet to identify the VTN the packet belongs to,
so as to perform resource specific packet processing. This is called
Resource Independent (RI) VTN.
This document proposes a mechanism to carry the VTN Identifier (VTN
ID) in the IPv6 extensions headers [RFC8200] of packet, so that the
packet will be processed by network nodes using the network resources
allocated to the corresponding VTN. The procedure of processing the
VTN ID is also specified. This provides a scalable solution for
enhanced VPN data plane, so that it could be used to support a large
number of transport network slices in IPv6 network.
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
BCP14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they
appear in all capitals, as shown here.
3. New IPv6 Extension Header Option for VTN
A new option type of IPv6 extension headers is defined to carry the
Virtual Transport Network Identifier (VTN ID) in IPv6 packet header.
Its format is shown as below:
Option Option Option
Type Data Len Data
+--------+--------+--------+--------+
|BBCTTTTT|00000100| 4-octet VTN ID |
+--------+--------+--------+--------+
Option Type: 8-bit identifier of the type of option. The type of VTN
option is TBD by IANA. The highest-order bits of the type field are
defined as below:
o BB 00 The highest-order 2 bits are set to 00 to indicate that a
node which does not recognize this type will skip over it and
continue processing the header.
o C 0 The third highest-order bit are set to 0 to indicate this
option does not change en route.
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Opt Data Len: 8-bit unsigned integer indicates the length of the
option Data field of this option, in octets. The value of Opt Data
Len of VTN option SHOULD be set to 4.
Option Data: 4-octet VTN which uniquely identifies a virtual
transport network.
Editor's note: The length of the VTN ID is defined as 4-octet
partially for the matching with the 4-octet network slice identifier
defined in 3GPP [TS23501].
8-bit 24-bit
+------------+-------------------------+
| SST | Slice Differentiator |
+------------+-------------------------+
4. Procedures
4.1. VTN Option Insertion
When an ingress node of an IPv6 or SRv6 domain receives a packet,
according to traffic classification or mapping policy, the packet
SHOULD be encapsulated in an outer IP header, and the VTN-ID of the
virtual transport network which the traffic is mapped to SHOULD be
carried in the extension header associated with the outer IPv6 header
. The ingress node MAY also encapsulate the SRH as defined in
[RFC8754] in the Routing Header of the outer IPv6 header.
In order to make the VTN option be processed by each node along the
path, it is RECOMMENDED that the VTN option be carried in IPv6
extension headers which can be processed hop-by-hop in forwarding
plane. It can be carried in either the Hop-by-Hop Options header, or
some new extension headers which can be processed on each hop along
the path.
4.2. VTN based Packet Forwarding
On receipt of a packet with the VTN option, each network node which
can parse the VTN option SHOULD use the VTN ID to identify the
virtual network the packet belongs to. This means the forwarding
behavior is based on both the destination IP address and the VTN
option.The destination IP address is used for the lookup of the next-
hop node, and VTN-ID can be used to determine the set of network
resources reserved for processing and sending the packet to the next-
hop node. The domain egress node SHOULD decapsulate the outer IPv6
header.
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There can be different implementations of reserving local network
resources to the VTNs. On each interface, the resources allocated to
a particular VTN can be seen as a virtual sub-interface with
dedicated bandwidth and other associated resources. In packet
forwarding, the IPv6 destination address of the received packet is
used to identify the next-hop and the outgoing interface, and the VTN
ID is used to further identify the virtual sub-interface which is
associated with the VTN on the outgoing interface.
Routers which do not support Hop-by-Hop options header SHOULD ignore
the Hop-by-Hop options header and forward the packet merely based on
the destination IP address. Routers which support Hop-by-Hop
Options, but do not recognize the VTN option SHOULD ignore the option
and continue to forward the packet merely based on the destination IP
address.
5. Operational Considerations
As described in [RFC8200], nodes may be configured to ignore the Hop-
by-Hop Options header, and the packets containing a Hop-by-Hop
Options header may be dropped or assigned to a slow processing path.
When VTN option is carried in Hop-by-Hop option header, operator
needs to make sure that all the network nodes involved in the VTN can
either process the Hop-by-Hop Options header in packet forwarding, or
ignore the Hop-by-Hop Option header but continue to forward the
packet based on other fields and headers. In other words, Packet
mapping to a VTN MUST NOT be dropped due to the existence of the Hop-
by-Hop Options header. It is RECOMMENDED to configure the nodes to
process the Hop-by-Hop Option header if there is a nob for this.
6. IANA Considerations
This document requests IANA to assign a new option type from
"Destination Options and Hop-by-Hop Options" registry.
Value Description Reference
------------------------------------------------------------
TBD Virtual Transport Network Identifier this document
7. Security Considerations
TBD
8. Contributors
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Zhibo Hu
Email: huzhibo@huawei.com
Lei Bao
Email: baolei7@huawei.com
9. Acknowledgements
The authors would like to thank Juhua Xu for his review and valuable
comments.
10. References
10.1. 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>.
[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>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
10.2. Informative References
[I-D.dong-teas-enhanced-vpn-vtn-scalability]
Dong, J., Li, Z., and F. Qin, "Virtual Transport Network
(VTN) Scalability Considerations for Enhanced VPN", draft-
dong-teas-enhanced-vpn-vtn-scalability-00 (work in
progress), February 2020.
[I-D.ietf-teas-enhanced-vpn]
Dong, J., Bryant, S., Li, Z., Miyasaka, T., and Y. Lee, "A
Framework for Enhanced Virtual Private Networks (VPN+)
Services", draft-ietf-teas-enhanced-vpn-05 (work in
progress), February 2020.
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
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[TS23501] "3GPP TS23.501", 2016,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3144>.
Authors' Addresses
Jie Dong
Huawei Technologies
Huawei Campus, No. 156 Beiqing Road
Beijing 100095
China
Email: jie.dong@huawei.com
Zhenbin Li
Huawei Technologies
Huawei Campus, No. 156 Beiqing Road
Beijing 100095
China
Email: lizhenbin@huawei.com
Chongfeng Xie
China Telecom
China Telecom Beijing Information Science & Technology, Beiqijia
Beijing 102209
China
Email: xiechf@chinatelecom.cn
Chenhao Ma
China Telecom
China Telecom Beijing Information Science & Technology, Beiqijia
Beijing 102209
China
Email: machh@chinatelecom.cn
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