Hi
Max-Forwards serves to limit the number of hops a request can make on the way to its destination. It consists of an integer that is decremented by one at each hop. A UAC MUST insert a Max-Forwards header field into each request it originates with a value that SHOULD be 70. This number was chosen to be sufficiently large to guarantee that a request would not be dropped in any SIP network when there were no loops, but not so large as to consume proxy resources when a loop does occur. Lower values should be used with caution and only in networks where topologies are known by the UA. Now, since the request has already reached the destination, the UAS can choose to ignore the Max-Forwards header. Following excerpts from RFC 4475, Session Initiation Protocol (SIP) Torture Test Messages also suggest the same. 3.1.2.4. Request Scalar Fields with Overlarge Values This request contains several scalar header field values outside their legal range. * The CSeq sequence number is >2**32-1. * The Max-Forwards value is >255. * The Expires value is >2**32-1. * The Contact expires parameter value is >2**32-1. An element receiving this request should respond with a 400 Bad Request due to the CSeq error. If only the Max-Forwards field were in error, the element could choose to process the request as if the field were absent. If only the expiry values were in error, the element could treat them as if they contained the default values for expiration (3600 in this case). Hope it helps. Regards, Tarun Gupta Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of manju nath Sent: Saturday, March 10, 2012 5:54 PM To: [email protected] Subject: [Sip-implementors] Max-FGorwards Header value greater than 255 in Request Hi all, I have doubt regarding the value of Max-forwards header, the doubt is what should be the behaviour of UAS if it receives an INVITE req with Max-Forwards value greater the 255?? does it has to reject the req it by 483 or 400??? plz reply it helps me alot , Thanks in advace... :) -- *Thanks & Regards,* *Manjunath.jootoor.* _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =============================================================================== _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
