DNS Reverse IP AMT (Automatic Multicast Tunneling) Discovery
draft-ietf-mboned-driad-amt-discovery-13
Mboned J. Holland
Internet-Draft Akamai Technologies, Inc.
Updates: 7450 (if approved) December 20, 2019
Intended status: Standards Track
Expires: June 22, 2020
DNS Reverse IP AMT (Automatic Multicast Tunneling) Discovery
draft-ietf-mboned-driad-amt-discovery-13
Abstract
This document updates RFC 7450 (Automatic Multicast Tunneling, or
AMT) by modifying the relay discovery process. A new DNS resource
record named AMTRELAY is defined for publishing AMT relays for
source-specific multicast channels. The reverse IP DNS zone for a
multicast sender's IP address is configured to use AMTRELAY resource
records to advertise a set of AMT relays that can receive and forward
multicast traffic from that sender over an AMT tunnel. Other
extensions and clarifications to the relay discovery process are also
defined.
Status of This Memo
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This Internet-Draft will expire on June 22, 2020.
Copyright Notice
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Holland Expires June 22, 2020 [Page 1]
Internet-Draft DRIAD December 2019
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1. Relays and Gateways . . . . . . . . . . . . . . . . . 4
1.2.2. Definitions . . . . . . . . . . . . . . . . . . . . . 4
2. Relay Discovery Overview . . . . . . . . . . . . . . . . . . 6
2.1. Basic Mechanics . . . . . . . . . . . . . . . . . . . . . 6
2.2. Signaling and Discovery . . . . . . . . . . . . . . . . . 6
2.3. Example Deployments . . . . . . . . . . . . . . . . . . . 9
2.3.1. Example Receiving Networks . . . . . . . . . . . . . 9
2.3.2. Example Sending Networks . . . . . . . . . . . . . . 12
3. Relay Discovery Operation . . . . . . . . . . . . . . . . . . 14
3.1. Optimal Relay Selection . . . . . . . . . . . . . . . . . 14
3.1.1. Overview . . . . . . . . . . . . . . . . . . . . . . 14
3.1.2. Preference Ordering . . . . . . . . . . . . . . . . . 15
3.1.3. Connecting to Multiple Relays . . . . . . . . . . . . 18
3.2. Happy Eyeballs . . . . . . . . . . . . . . . . . . . . . 18
3.2.1. Overview . . . . . . . . . . . . . . . . . . . . . . 18
3.2.2. Algorithm Guidelines . . . . . . . . . . . . . . . . 19
3.2.3. Connection Definition . . . . . . . . . . . . . . . . 20
3.3. Guidelines for Restarting Discovery . . . . . . . . . . . 20
3.3.1. Overview . . . . . . . . . . . . . . . . . . . . . . 20
3.3.2. Updates to Restarting Events . . . . . . . . . . . . 21
3.3.3. Tunnel Stability . . . . . . . . . . . . . . . . . . 22
3.3.4. Traffic Health . . . . . . . . . . . . . . . . . . . 22
3.3.5. Relay Loaded or Shutting Down . . . . . . . . . . . . 24
3.3.6. Relay Discovery Messages vs. Restarting Discovery . . 24
3.3.7. Independent Discovery Per Traffic Source . . . . . . 25
3.4. DNS Configuration . . . . . . . . . . . . . . . . . . . . 25
3.5. Waiting for DNS resolution . . . . . . . . . . . . . . . 26
4. AMTRELAY Resource Record Definition . . . . . . . . . . . . . 26
4.1. AMTRELAY RRType . . . . . . . . . . . . . . . . . . . . . 26
4.2. AMTRELAY RData Format . . . . . . . . . . . . . . . . . . 27
4.2.1. RData Format - Precedence . . . . . . . . . . . . . . 27
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