From 284cd96886e3e2199a400bdb39644d8da9ffcee4 Mon Sep 17 00:00:00 2001 From: Jonathan Hui Date: Tue, 30 Jun 2020 08:48:08 -0700 Subject: [PATCH] [devsite] add clarifications to multicast addressing primer (#5160) --- doc/site/en/guides/thread-primer/ipv6-addressing.md | 10 ++++++---- .../en/guides/thread-primer/node-roles-and-types.md | 5 +++-- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/doc/site/en/guides/thread-primer/ipv6-addressing.md b/doc/site/en/guides/thread-primer/ipv6-addressing.md index 329f19d48..3f38d7381 100644 --- a/doc/site/en/guides/thread-primer/ipv6-addressing.md +++ b/doc/site/en/guides/thread-primer/ipv6-addressing.md @@ -226,10 +226,12 @@ Key Point: A major difference between FTDs and MTDs are that FTDs subscribe to the `ff03::2` multicast address. MTDs do not. You might notice that Sleepy End Devices (SEDs) are not included as a -recipient in the multicast table above. There is an additional unicast -prefix-based multicast address used for All Thread Nodes, including SEDs. This -multicast address varies by Thread network, because it is built on the -unicast Mesh-Local prefix. +recipient in the multicast table above. Instead, Thread defines +link-local and realm-local scope unicast prefix-based IPv6 multicast +address used for All Thread Nodes, including SEDs. These multicast +addresses vary by Thread network, because it is built on the unicast +Mesh-Local prefix (see [RFC 3306](https://tools.ietf.org/html/rfc3306) +for more details on unicast-prefix-based IPv6 multicast addresses). Arbitrary scopes beyond those already listed are also supported for Thread devices. diff --git a/doc/site/en/guides/thread-primer/node-roles-and-types.md b/doc/site/en/guides/thread-primer/node-roles-and-types.md index 888b4c7d2..2db6213c7 100644 --- a/doc/site/en/guides/thread-primer/node-roles-and-types.md +++ b/doc/site/en/guides/thread-primer/node-roles-and-types.md @@ -50,8 +50,9 @@ An FTD can operate as a Router (Parent) or an End Device (Child). ### Minimal Thread Device -A Minimal Thread Device does not subscribe to multicast traffic and forwards all -messages to its Parent. There are two types of MTDs: +A Minimal Thread Device does not subscribe to the all-routers +multicast address and forwards all messages to its Parent. There are +two types of MTDs: * Minimal End Device (MED) — transceiver always on, does not need to poll for messages from its parent