IS-IS TE Attributes per application
draft-ietf-isis-te-app-11
Networking Working Group L. Ginsberg
Internet-Draft P. Psenak
Intended status: Standards Track Cisco Systems
Expires: August 30, 2020 S. Previdi
Huawei
W. Henderickx
Nokia
J. Drake
Juniper Networks
February 27, 2020
IS-IS TE Attributes per application
draft-ietf-isis-te-app-11
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.,
Segment Routing Traffic Engineering, Loop Free Alternate) 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 document introduces new link attribute advertisements
which address both of these shortcomings.
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Ginsberg, et al. Expires August 30, 2020 [Page 1]
Internet-Draft draft-ietf-isis-te-app February 2020
Internet-Drafts are draft documents valid for a maximum of six months
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 August 30, 2020.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Discussion . . . . . . . . . . . . . . . . . . . 4
3. Legacy Advertisements . . . . . . . . . . . . . . . . . . . . 4
3.1. Legacy sub-TLVs . . . . . . . . . . . . . . . . . . . . . 5
3.2. Legacy SRLG Advertisements . . . . . . . . . . . . . . . 5
4. Advertising Application Specific Link Attributes . . . . . . 6
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 . . . . . . . . . . . . . . . . . . . . . . 10
4.2.3. Considerations for Extended TE Metrics . . . . . . . 10
4.3. Application Specific SRLG TLV . . . . . . . . . . . . . . 10
5. Attribute Advertisements and Enablement . . . . . . . . . . . 11
6. Deployment Considerations . . . . . . . . . . . . . . . . . . 12
6.1. Use of Legacy Advertisements . . . . . . . . . . . . . . 12
6.2. Use of Zero Length Application Identifier Bit Masks . . . 13
6.3. Interoperability, Backwards Compatibility and Migration
Concerns . . . . . . . . . . . . . . . . . . . . . . . . 14
6.3.1. Multiple Applications: Common Attributes with RSVP-
TE . . . . . . . . . . . . . . . . . . . . . . . . . 14
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