Subject: [MMUSIC] Proposed change in 4566bis for private addresses

From: "Ali C. Begen (abegen)" <[email-masked]>
Date: Mon, 6 Feb 2012 21:42:25 +0000

Currently, RFC 4566 section 5.2 states the following:

   <unicast-address> is the address of the machine from which the
      session was created.  For an address type of IP4, this is either
      the fully qualified domain name of the machine or the dotted-
      decimal representation of the IP version 4 address of the machine.
      For an address type of IP6, this is either the fully qualified
      domain name of the machine or the compressed textual
      representation of the IP version 6 address of the machine.  For
      both IP4 and IP6, the fully qualified domain name is the form that
      SHOULD be given unless this is unavailable, in which case the
      globally unique address MAY be substituted.  A local IP address
      MUST NOT be used in any context where the SDP description might
      leave the scope in which the address is meaningful (for example, a
      local address MUST NOT be included in an application-level
      referral that might leave the scope).

The last portion contradicts with what ICE-like solutions have. So, we suggest to change the last portion as:

<new>
       Unless an SDP extension for NAT traversal is used (e.g., ICE [RFC
       5245], ICE TCP [draft-ietf-mmusic-ice-tcp]) a local IP address
       MUST NOT be used in any context where the SDP description might
       leave the scope in which the address is meaningful (for example, a
       local address MUST NOT be included in an application-level
       referral that might leave the scope).
</new>

And the referred RFC/draft will be added to the informative reference list.

Please comment on this change. A new revision will be posted well before the next meeting.

Thanks,
-acbegen

---

From: "Miguel A. Garcia" <[email-masked]>
Date: Tue, 7 Feb 2012 14:49:03 +0100

I do agree with the proposal.

/Miguel

On 06/02/2012 22:42, Ali C. Begen (abegen) wrote:
> _______________________________________________
> mmusic mailing list
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>

-- 
Miguel A. Garcia
+34-91-339-3608
Ericsson Spain

---

From: "Kevin P. Fleming" <[email-masked]>
Date: Mon, 13 Feb 2012 17:32:49 -0600

> I do agree with the proposal.

I also agree with the proposal, although after the first time I read it 
I wasn't sure. I think the issue is that use of ICE (or similar 
mechanisms) makes it impractical for the offerer to know conclusively 
what the 'scope' of an SDP description actually is. Since that is the 
case, the safer route is to allow local addresses to appear in the SDP 
description, in case they can be used by the receiver.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
Jabber: [email-masked] | SIP: [email-masked] | Skype: kpfleming
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at www.digium.com & www.asterisk.org