IS-IS TE Attributes per application
draft-ietf-isis-te-app-09
Networking Working Group L. Ginsberg
Internet-Draft P. Psenak
Intended status: Standards Track Cisco Systems
Expires: May 2, 2020 S. Previdi
Huawei
W. Henderickx
Nokia
J. Drake
Juniper Networks
October 30, 2019
IS-IS TE Attributes per application
draft-ietf-isis-te-app-09
Abstract
Existing traffic engineering related link attribute advertisements
have been defined and are used in RSVP-TE deployments. Since the
original RSVP-TE use case was defined, additional applications (e.g.,
SRTE, LFA) have been defined which also make use of the link
attribute advertisements. In cases where multiple applications wish
to make use of these link attributes the current advertisements do
not support application specific values for a given attribute nor do
they support indication of which applications are using the
advertised value for a given link.
This draft introduces new link attribute advertisements which address
both of these shortcomings. It also discusses backwards
compatibility issues and how to minimize duplicate advertisements in
the presence of routers which do not support the extensions defined
in this document.
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.
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
Ginsberg, et al. Expires May 2, 2020 [Page 1]
Internet-Draft draft-ietf-isis-te-app October 2019
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 May 2, 2020.
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Discussion . . . . . . . . . . . . . . . . . . . 3
3. Legacy Advertisements . . . . . . . . . . . . . . . . . . . . 4
3.1. Legacy sub-TLVs . . . . . . . . . . . . . . . . . . . . . 4
3.2. Legacy SRLG Advertisements . . . . . . . . . . . . . . . 5
4. Advertising Application Specific Link Attributes . . . . . . 5
4.1. Application Identifier Bit Mask . . . . . . . . . . . . . 6
4.2. Application Specific Link Attributes sub-TLV . . . . . . 8
4.2.1. Special Considerations for Maximum Link Bandwidth . . 9
4.2.2. Special Considerations for Reservable/Unreserved
Bandwidth . . . . . . . . . . . . . . . . . . . . . . 9
4.3. Application Specific SRLG TLV . . . . . . . . . . . . . . 9
5. Deployment Considerations . . . . . . . . . . . . . . . . . . 10
5.1. Use of Legacy Advertisements . . . . . . . . . . . . . . 11
5.2. Use of Zero Length Application Identifier Bit Masks . . . 11
6. Attribute Advertisements and Enablement . . . . . . . . . . . 12
7. Interoperability, Backwards Compatibility and Migration
Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Multiple Applications: Common Attributes with RSVP-TE . 13
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