Carrying Virtual Transport Network Identifier in IPv6 Extension Header
draft-dong-6man-enhanced-vpn-vtn-id-03
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 | 2021-02-22 (Latest revision 2020-11-02) | ||
| 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 | |||
| 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-03
Network Working Group J. Dong
Internet-Draft Z. Li
Intended status: Standards Track Huawei Technologies
Expires: August 26, 2021 C. Xie
C. Ma
China Telecom
February 22, 2021
Carrying Virtual Transport Network Identifier in IPv6 Extension Header
draft-dong-6man-enhanced-vpn-vtn-id-03
Abstract
A Virtual Transport Network (VTN) is a virtual network which has a
customized network topology and a set of dedicated or shared network
resources allocated from the network infrastructure. A VTN can be
used as the underlay for one or a group of VPNs to provide enhanced
VPN (VPN+) services. In packet forwarding, some fields in data
packet needs to be used to identify the VTN the packet belongs to, so
that the VTN-specific processing can be performed.
This document proposes a new option type to carry VTN ID in an IPv6
extension header to identify the Virtual Transport Network (VTN) the
packet belongs to. The procedure for processing of the VTN option is
also specified.
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
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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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 August 26, 2021.
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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
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. New IPv6 Extension Header Option for VTN . . . . . . . . . . 3
3. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. VTN Option Insertion . . . . . . . . . . . . . . . . . . 4
3.2. VTN based Packet Forwarding . . . . . . . . . . . . . . . 4
4. Operational Considerations . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 6
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Virtual Private Networks (VPNs) provide different groups of users
with logically isolated connectivity over a common shared network
infrastructure. With the introduction of 5G, new service types may
require connectivity services with advanced characteristics comparing
to traditional VPNs, such as strict isolation from other services or
guaranteed performance. These services are refered to as "enhanced
VPNs" (VPN+). [I-D.ietf-teas-enhanced-vpn] describes a framework and
candidate component technologies for providing VPN+ services.
The enhanced properties of VPN+ require tighter coordination and
integration between the underlay network resources and the overlay
network. VPN+ service can be built on a Virtual Transport Network
(VTN) which has a customized network topology and a set of dedicated
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or shared network resources allocated from the physical network. The
overlay VPN together with the corresponding VTN in the underlay
constitute 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.
[I-D.dong-teas-enhanced-vpn-vtn-scalability] describes the
scalability considerations for VPN+, one approach to improve the data
plane scalability is by introducing a dedicated VTN Identifier (VTN
ID) in data packets to identify the VTN the packets belong to, so
that VTN-specific packet processing can be performed. This is called
Resource Independent (RI) VTN.
This document proposes a mechanism to carry the VTN ID in an IPv6
extension header [RFC8200] of a packet, so that the packet will be
processed by network nodes using the network resources allocated to
the corresponding VTN. The procedure for processing the VTN ID is
also specified. This provides a scalable solution for enhanced VPN
data plane, so that it may be used to support a large number of VTNs
in an IPv6 network.
1.1. 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
BCP14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they
appear in all capitals, as shown here.
2. New IPv6 Extension Header Option for VTN
A new option type "VTN" is defined to carry the Virtual Transport
Network Identifier (VTN ID) in an IPv6 packet header. Its format is
shown as below:
Option Option Option
Type Data Len Data
+--------+--------+--------+--------+
|BBCTTTTT|00000100| 4-octet VTN ID |
+--------+--------+--------+--------+
Figure 1. The format of VTN Option
Option Type: 8-bit identifier of the type of option. The type of VTN
option is to be assigned by IANA. The highest-order bits of the type
field are defined as below:
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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.
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 identifier which uniquely identifies a VTN.
Editor's note: The length of the VTN ID is defined as 4-octet for the
matching with the 4-octet Single Network Slice Selection Assistance
Information (S-NSSAI) defined in 3GPP [TS23501].
8-bit 24-bit
+------------+-------------------------+
| SST | Slice Differentiator |
+------------+-------------------------+
Figure 2. The format of S-NSSAI
3. Procedures
As the VTN option needs to be processed by each node along the path
for VTN-specific forwarding, it SHOULD be carried in IPv6 Hop-by-Hop
options header when the Hop-by-Hop options header can be processed in
forwarding plane by all the nodes along the path.
3.1. VTN Option Insertion
When an ingress node of an IPv6 domain receives a packet, according
to traffic classification or mapping policy, the packet is steered
into one of the VTNs in the network, then the packet SHOULD be
encapsulated in an outer IPv6 header, and the VTN-ID of the VTN which
the packet is mapped to SHOULD be carried in the Hop-by-Hop options
header associated with the outer IPv6 header.
3.2. 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 VTN
the packet belongs to, so that the set of local resources allocated
to the VTN could be determined. The packet 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 and the
outgoing interface, and VTN-ID is used to determine the set of
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network resources reserved for processing and sending the packet to
the next-hop node via the outgoing interface. The egress node of the
IPv6 domain SHOULD decapsulate the outer IPv6 header which includes
the VTN option.
In the forwarding plane, there can be different instantiations of
local network resources allocated to the VTNs. For example, on one
interface, a subset of forwarding plane resources (e.g. the bandwidth
and the associated buffer/queuing/scheduling resources) allocated to
a particular VTN can be considered as a virtual sub-interface with
dedicated 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 only based on
the destination IP address. Routers which support Hop-by-Hop Options
header, but do not support the VTN option SHOULD ignore the Hop-by-
Hop option and continue to forward the packet only based on the
destination IP address.
4. Operational Considerations
As described in [RFC8200], nodes may be configured to ignore the Hop-
by-Hop Options header, and in some implementations a packet
containing a Hop-by-Hop Options header may be dropped or assigned to
a slow processing path. This needs to be taken into consideration
when VTN option is introduced to a network. The operator needs to
make sure that all the network nodes in a VTN can either process Hop-
by-Hop Options header in packet forwarding, or ignore the Hop-by-Hop
Option header. In other word, packets steered into a VTN MUST NOT be
dropped due to the existence of the Hop-by-Hop Options header. It is
RECOMMENDED to configure all the nodes in a VTN to process the Hop-
by-Hop Options header if there is a nob for this.
5. 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 VTN Option this document
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6. Security Considerations
TBD
7. Contributors
Zhibo Hu
Email: huzhibo@huawei.com
Lei Bao
Email: baolei7@huawei.com
8. Acknowledgements
The authors would like to thank Juhua Xu and James Guichard for their
review and valuable comments.
9. References
9.1. 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>.
9.2. Informative References
[I-D.dong-teas-enhanced-vpn-vtn-scalability]
Dong, J., Li, Z., Qin, F., and G. Yang, "Scalability
Considerations for Enhanced VPN (VPN+)", draft-dong-teas-
enhanced-vpn-vtn-scalability-01 (work in progress),
November 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+)
Service", draft-ietf-teas-enhanced-vpn-06 (work in
progress), July 2020.
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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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