[MMUSIC] draft-ietf-mmusic-ice-19 question

[Jim Kleck <jimk at 8x8.com>]

In looking at draft-ietf-mmusic-ice-19, we have run into a
point of confusion. Our understanding of the draft is that all
local candidates for a particular component for a mediastream
should use the same host IP Addr & port for gathering candidates
and for sending and receiving connectivity checks: section  4.1.1.2
says:

The agent next pairs each host candidate with the STUN or TURN server
   with which it is configured or has discovered by some means.

and:

The result is a set of pairs of host candidates with STUN or TURN
   servers.


However, section 7.2.1.4 (which deals with the ICE agent processing
a received Binding Request) states:

   Next, the agent constructs a pair whose local candidate is equal to
   the transport address on which the STUN request was received, and a
   remote candidate equal to the source transport address where the
   request came from (which may be peer-reflexive remote candidate that
   was just learned).


If all local candidates for a component have the same host IPaddr:port,
how can the local agent determine which transport address the remote
agent sent the request to (which I assume is the first transport address
referenced in the 7.2.1.4 quote from the draft)? I dont see anything in
the STUN Binding Request pkt which identifies the target candidate,
nor does the IPaddr:port the request was received on identify the target
candidate. Or does the local agent actually need a different host IPaddr
and port for each local transport address?

James Kleck
8x8, Inc.