Subject: [straw] Spencer Dawkins' No Objection on draft-ietf-straw-b2bua-stun-05: (with COMMENT)

From: "Spencer Dawkins" <[email-masked]>
Date: Mon, 11 May 2015 20:35:32 -0700

Spencer Dawkins has entered the following ballot position for
draft-ietf-straw-b2bua-stun-05: No Objection

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COMMENT:
----------------------------------------------------------------------

No objection, but a couple of places where the text seemed rough:

In this text:

   For these
   and other reasons, B2BUAs were already being used by SIP domains for
   other SIP and media-related purposes began to use proprietary
   mechanisms to enable SIP devices behind NATs to communicate across
   the NAT.
   
Does this sentence parse?

In this text:

   The most commonly used approach to solve these issues is
   "restricted-latching", whereby the B2BUA will not latch to any
   packets from a source public IP address other than the one the SIP UA
   uses for SIP signaling.
   
Is the phrase "will not latch to" clear to the intended reader? The
sentence is defining a type of latching, but there's not a description of
what latching means in the general sense. The following section says
terms are defined in https://tools.ietf.org/html/rfc7092, but I didn't
see "latch" in a quick text search over there. Is the reference to
https://tools.ietf.org/html/rfc7362 earlier in the paragraph also to the
description of "latching"?

In this text:

   o  A B2BUA that acts as a simple media relay effectively unaware of
      anything that is transported and only modifies the transport
      header (could be UDP/IP) of the media packets.

   o  A B2BUA that performs a media-aware role.  It inspects and
      potentially modifies RTP or RTP Control Protocol (RTCP) headers;
      but it does not modify the payload of RTP/RTCP.

   o  A B2BUA that performs a media-termination role and operates at the
      media payload layer, such as RTP/RTCP payload (e.g., a
      transcoder).

   When such a B2BUA operating on a media plane is involved in a session
   between two endpoints performing ICE, then it MUST follow the
   behavior described in Section 4.
   
I"m reading "such a B2BUA" as a reference to the third bullet, but it
would be clearer to me if both places used the same terms ("operates at
the media payload layer" vs. "operating on a media plane").

---

From: "Ram Mohan R (rmohanr)" <[email-masked]>
Date: Tue, 12 May 2015 12:40:19 +0000

Hi Spencer,

Please see inline

-----Original Message-----
From: Spencer Dawkins <[email-masked]>
Date: Tuesday, 12 May 2015 9:05 am
To: The IESG <[email-masked]>
Cc: "[email-masked]"
<[email-masked]>,
"[email-masked]"
<[email-masked]>,
"[email-masked]"
<[email-masked]>, "[email-masked]"
<[email-masked]>, Victor Pascual <[email-masked]>,
"[email-masked]" <[email-masked]>
Subject: Spencer Dawkins' No Objection on draft-ietf-straw-b2bua-stun-05:
(with COMMENT)

>https://datatracker.ietf.org/doc/draft-ietf-straw-b2bua-stun/

This comment was already given by Barry and we have proposed a new text as
below.
Let me know if this sounds better

NEW:
For these reasons, B2BUAs are being used by SIP domains for
SIP and media-related purposes. These B2BUAs use proprietary
mechanisms to enable SIP devices behind NATs to communicate across
the NAT.

>description of "latching"?

Latching is defined in RFC7362. Will add reference to this RFC in that
line. New proposed text is below. Is this better ?

NEW:
The most commonly used approach to solve these issues is
restricted-latching defined in section 5 of [RFC7362], whereby the B2BUA
will not latch to any
   packets from a source public IP address other than the one the SIP UA
uses for SIP signalling.

>the media payload layer" vs. "operating on a media plane").

Note that the section 4 is applicable for B2BUAs operating on media plane
(all three types above).
Will fix this to say

NEW:
"When B2BUAs that operate on media plane (media relay, media-aware or
media-termination) is involved in a session........²

Is this better ?

Regards,
Ram