Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints
draft-hegde-lsr-flex-algo-bw-con-01
SPRING S. Hegde
Internet-Draft W. Britto
Intended status: Standards Track R. Shetty
Expires: September 9, 2021 Juniper Networks Inc.
B. Decraene
Orange
P. Psenak
Cisco Systems
T. Li
Arista Networks
March 8, 2021
Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints
draft-hegde-lsr-flex-algo-bw-con-01
Abstract
Many networks configure the link metric relative to the link
capacity. High bandwidth traffic gets routed as per the link
capacity. Flexible algorithms provides mechanisms to create
constraint based paths in IGP. This draft documents a set of
bandwidth related constraints to be used in Flexible Algorithms.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
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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This Internet-Draft will expire on September 9, 2021.
Hegde, et al. Expires September 9, 2021 [Page 1]
Internet-Draft Flex-Algorithm Bandwidth Constraints March 2021
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Bandwidth Metric Advertisement . . . . . . . . . . . . . . . 3
2.1. ISIS Bandwidth Metric sub-TLV . . . . . . . . . . . . . . 4
2.2. OSPF Bandwidth Metric sub-TLV . . . . . . . . . . . . . . 5
3. FAD constraint sub-TLVs . . . . . . . . . . . . . . . . . . . 5
3.1. ISIS FAD constraint sub-TLVs . . . . . . . . . . . . . . 6
3.1.1. ISIS Exclude Minimum Bandwidth sub-TLV . . . . . . . 6
3.1.2. ISIS Exclude Maximum Delay sub-TLV . . . . . . . . . 7
3.2. OSPF FAD constraint sub-TLVs . . . . . . . . . . . . . . 7
3.2.1. OSPF Exclude Minimum Bandwidth sub-TLV . . . . . . . 8
3.2.2. OSPF Exclude Maximum Delay sub-TLV . . . . . . . . . 8
4. Automatic Metric Calculation . . . . . . . . . . . . . . . . 9
4.1. Automatic Metric Calculation Modes . . . . . . . . . . . 10
4.1.1. Simple Mode . . . . . . . . . . . . . . . . . . . . . 10
4.1.2. Interface Group Mode . . . . . . . . . . . . . . . . 10
4.2. Automatic Metric Calculation Methods . . . . . . . . . . 10
4.2.1. Reference Bandwidth method . . . . . . . . . . . . . 11
4.2.2. Bandwidth Thresholds method . . . . . . . . . . . . . 11
4.3. ISIS FAD constraint sub-TLVs for automatic metric
calculation . . . . . . . . . . . . . . . . . . . . . . . 11
4.3.1. Reference Bandwidth sub-TLV . . . . . . . . . . . . . 11
4.3.2. Bandwidth Thresholds sub-TLV . . . . . . . . . . . . 13
4.4. OSPF FAD constraint sub-TLVs for automatic metric
calculation . . . . . . . . . . . . . . . . . . . . . . . 15
4.4.1. Reference Bandwidth sub-TLV . . . . . . . . . . . . . 15
4.4.2. Bandwidth Threshold sub-TLV . . . . . . . . . . . . . 17
5. Bandwidth metric considerations . . . . . . . . . . . . . . . 19
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