Query related to Expires header with value 0 in INVITE

"Anita Tailor" <[email protected]>
Newsgroups gmane.ietf.sip
Message-ID <[email protected]>
Hi All,

I have some queries related to expires header in SIP message.

RFC 3261 Section 20.19
" The value of this field is an integral number of seconds (in decimal)
   between 0 and (2**32)-1, measured from the receipt of the request"

Does this mean 0 is a valid value of Expires header ? I am confused because of "between" word here as meaning might different if "from 0 to  (2**32)-1" have used.

Does Expires value in INVITE is modified by intermittent SIP entities before it reaches to its destination?
If yes, then what should be UAS behavior when it receives INVITE with value 0 in Expires header ? Should UAS respond with 487 ?

Section 13.1.1 [1]
  "If the request is an INVITE that contains an Expires header
 field, the UAS core sets a timer for the number of seconds
 indicated in the header field value.  When the timer fires, the
 invitation is considered to be expired.  If the invitation
 expires before the UAS has generated a final response, a 487
 (Request Terminated) response SHOULD be generated."


Thanks in Advance
Anita



Conexant E-mail Firewall (Conexant.Com) made the following annotations
---------------------------------------------------------------------
********************** Legal Disclaimer **************************** 

"This email may contain confidential and privileged material for the sole use of the intended recipient. Any unauthorized review, use or distribution by others is strictly prohibited. If you have received the message in error, please advise the sender by reply email and delete the message. Thank you." 

********************************************************************** 

---------------------------------------------------------------------

_______________________________________________
Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email protected] for questions on current sip
Use [email protected] for new developments on the application of sip
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.