Subject: [apps-discuss] APPSDIR review of draft-ietf-straw-sip-traceroute-02

From: "Vijay K. Gurbani" <[email-masked]>
Date: Tue, 24 Jun 2014 09:49:29 -0500

I have been selected as the Applications Area Directorate reviewer for
this draft (for background on appsdir, please see ​
http://trac.tools.ietf.org/area/app/trac/wiki/ApplicationsAreaDirectorate).

Please resolve these comments along with any other Last Call comments
you may receive. Please wait for direction from your document shepherd
or AD before posting a new version of the draft.

Document:  draft-ietf-straw-sip-traceroute-02
Title: A Media-based Traceroute Function for the Session Initiation
  Protocol (SIP)
Reviewer: Vijay K. Gurbani
Review Date: Jun 24-2014
IETF Last Call Date: Jul-04-2014
IESG Telechat Date: Jul-10-2014

Summary: This draft is ready for publication as a Proposed Standard.
Some nits and a confirmation (1 minor issue) below will require some
attention.

Major: 0
Minor: 1
Nits:  Various

Minor:

- Just a confirmation: we are not defining a Required or Supported
  token for the traceroute mechanism described in the draft?  S3, second
  paragraph states that, "or if the next-hop is a B2BUA that supports
  this mechanism, and if the B2BUA allows such testing from the
  requesting UAC,"  Here, our implicit assumption is that a B2BUA
  functionality will be upgraded automatically such that if it sees a
  M-F of 0 it create a media loopback session.  If the B2BUA does not
  support creation of media loopback sessions, it simply sends a 483.

  In addition, B2BUAs that support creation of media streams MUST
  insert a SIP Reason header field cause value of 483.

  It seems that the support of the traceroute mechanisms requires some
  non-trivial steps by the B2BUA.  But we are doing this without
  requiring any tokens in Required or Supported header and depending
  on configured policies (c.f., S3.2).  Yes?

- S3, third paragraph: Before creating another INV with a M-F of 1,
  the UAC should tear down the previous session.  This is implicit
  behaviour of any sane implementation course, but should be stated
  nonetheless.

Nits:

- Abstract:
  s/field, in order to/field to/

  s/generated which result/generated that result/

  s/mechanism, in order to test/mechanism to/

- S2:
  s/rich-ringtones/rich ringtones/

  s/As more and more SIP domains get deployed and interconnect/As
  increasingly more SIP domains get deployed and interconnected/

  s/If failures or degradation occur in the media plane, it is difficult
  to determine where in the media path they occur./When a failure or
  degradation occurs in the media plane, it is difficult to determine
  where in the media path it occurred./

  s/and media crossing/and media traversing/

  s/to be able to progressively test/to progressively test/

  s/will be crossed/will be traversed/

  s/what URIs to/which URIs to/

-S3:
  s/originating UAC generates/originating UAC (Alice) generates/

  s/a target AoR/a target AoR (Bob)/

Thanks,

- vijay
-- 
Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
1960 Lucent Lane, Rm. 9C-533, Naperville, Illinois 60563 (USA)
Email: vkg@{bell-labs.com,acm.org} / [email-masked]
Web: http://ect.bell-labs.com/who/vkg/  | Calendar: http://goo.gl/x3Ogq