Subject: [sipcore] WGLC draft-ietf-sipcore-rfc4244bis-callflows-01: section 3.1, 3.4, 3.6 comments

From: Laura Liess <[email-masked]>
Date: Wed, 17 Oct 2012 13:26:04 +0200

Hi,

Please find additional comments on the sections 3.1, 3.4 and 3.6:

1) 3.1,  second paragraph: "In other words, Office and *Bob* are not
bound through SIP Registration   with Bob's AOR."  should be "In other
words, Office and *Home* are not bound through SIP Registration  with
Bob's AOR."

2) 3.1  third paragraph:  It seems to me that something is missing in
the sentence " Thus, avoiding  another INVITE to Bob's home phone."

3) 3.1, message F5:   My understanding is that 192.0.2.4 is the
registred IP-address of  Bob, not of the example.com proxy. In this
case, " F5 ACK 192.0.2.4 -> Bob"  should be " F5 ACK example.com ->
Bob".

4) 3.4,  diagram. The diagram shows the Gold and Silver entities, in
the detailed messages we find "F2 INVITE Example.com ->
Gold.Example.com".

5) 3.4,  messages F2 and F4:
  RFC4244bis , Section 9.2 says: "The hi-targeted-to-uri MUST be set
to the value of the Request-URI of the current (outgoing) request."
   In F2 we have:  Request URI =  sip:[email-masked] and last
hi-targeted-to-uri = <sip:[email-masked]>. I think the
Request-RI should be [email-masked].
    In F4 we have:  Request URI =  sip:[email-masked]  and last
hi-targeted-to-uri = <sip:[email-masked]>. I think the
Request-URI should be [email-masked].

 6) 3.4, message F9: Is the H-I in ACK OK? rfc4244bis , section 5: "
The History-Info header field defined in this specification defines
the usage in out-of-dialog requests or initial requests for a dialog
(e.g., INVITE, REGISTER, MESSAGE, REFER and OPTIONS, PUBLISH and
SUBSCRIBE, etc.) and any non-100 provisional or final responses to
these requests."  I seems to me is that H-I is not to be used in ACK.
( Note:The ACK messages in 3.1 do not contain a H-I.I think this is
OK.)

7) 3.6,  message F1: I would expect to find a  History-Info:
<sip:[email-masked]>;index=1  in this message?

8) 3.6, message F3: mp=1 missing in the Contact: -header.

9) 3.6, messages F6 and F7:  History-Info: <sip:[email-masked];\
target=sip:bob%40example.com;cause=408>;\index=1.3;mp=1.2
    I MO mp=1.2 is not correct. RFC4244bis says on page 8: "The "mp"
header field parameter contains the value of the hi-index in the
hi-entry with an hi-targeted-to-uri that reflects the Request-URI that
was retargeted, thus identifying the "mapped from" target." IMO,
because it's Bob's VM, the hi-entry with an hi-targeted-to-uri that
reflects the Request-URI that was retargeted is in this case
<sip:[email-masked]> with index=1 and not <sip:[email-masked]> so
I would expect here mp=1.  If the call would have been retargeted to
Carol's VM, we would have mp=1.2. But maybe I missed something here.
(Note: I do not see any difference to the message F9 in 3.1, where we
have  mp=1.)

10) 3.6, message F7: Contact: <sip:[email-masked]> seems wrong to me,
it should be the VM.

Thanks,
Laura