IP Node receive Cancel with mimebody

[sudhagup]

Hi All,

Please assist me with the below query in reference to SIP RFC standards:

If a node receive Cancel with mimebody (ISUP: REL) (the INVITE received had no mime body), should node respond with 415 - unsupported media and a 200 ok sdp thereafter; or 487 - Request Terminated.

Also, any document link supporting the answers will be much appreciated.

Regards

[Vivek Batra]

Hi,

Please check following excerpt from RFC 5621;

 Legacy SIP UAs without support for 'multipart' bodies generate a 415
   (Unsupported Media Type) response when they receive a 'multipart'
   body in a request.  A UAC sending a 'multipart' body can receive such
   an error response when communicating with a legacy SIP UA that
   predates this specification.

      It has been observed in the field that a number of legacy SIP UAs
      without support for 'multipart' bodies simply ignored those bodies
      when they were received.  These UAs did not return any error
      response.  Unsurprisingly, SIP UAs not being able to report this
      type of error have caused serious interoperability problems in the
      past.

So it can be perceived that if UA can not interpret multi-part message body, it can either reject the request or ignore the content and proceed accordingly.

IMO, SIP implementors group will be better place to put this question and get some more feedback's as well.

- Vivek