Generic Transport Functions
draft-zzhang-tsvwg-generic-transport-functions-00
tsvwg Z. Zhang
Internet-Draft R. Bonica
Intended status: Standards Track K. Kompella
Expires: May 5, 2021 Juniper Networks
November 01, 2020
Generic Transport Functions
draft-zzhang-tsvwg-generic-transport-functions-00
Abstract
Some functionalities (e.g. fragmentation/reassembly and Encapsulating
Security Payload) provided by IPv6 can be viewed as independent of
IPv6 or even IP entirely. This document proposes to provide those
functionalities at different layers (e.g., MPLS, BIER or even
Ethernet) independent of IP.
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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and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 5, 2021.
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Zhang, et al. Expires May 5, 2021 [Page 1]
Internet-Draft Generic Transport Functions November 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Specifications . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Generic Fragmentation Header . . . . . . . . . . . . . . 4
2.2. MPLS Signaling . . . . . . . . . . . . . . . . . . . . . 5
2.2.1. BGP Signaling . . . . . . . . . . . . . . . . . . . . 5
2.2.2. IGP Signaling . . . . . . . . . . . . . . . . . . . . 6
2.3. Generic ESP/Authentication Header . . . . . . . . . . . . 6
3. Security Considerations . . . . . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Consider an operator providing Ethernet services such as pseudowires,
VPLS or EVPN. The Ethernet frames that a Provider Edge (PE) device
receives from a Customer Edge (CE) device may have a larger size than
the PE-PE path MTU (pMTU) in the provider network. This could be
because
1. the provider network is built upon virtual connections (e.g.
pseudowires) provided by another infrastructure provider, or
2. the customer network uses jumbo frames while the provider network
does not, or
3. the provider-side overhead for transporting customers packets
across the network pushes past the pMTU.
In any case, the provider simply cannot require its customers to
change their MTU.
To get those large frames across the provider network, currently the
only workaround is to encapsulate the frames in IP (with or without
GRE) and then fragment the IP packets. Even if MPLS is used for
service delimiting, IP is used for transporation (MPLS over IP/GRE).
This may not be desirable in certain deployment scenarios, where MPLS
is the preferred transport or IP encapsulation overhead is deemed
excessive.
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IPv6 fragmentation and reassembly are based on the IPv6 Fragmentation
header below [RFC8200]:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Reserved | Fragment Offset |Res|M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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