With UDP transport you can do so by checking if the udp has SIP/2.0 Something like *p++=='S' && *p=='I' && *p++='P'
where p is the pointer to your packet data. For rtcp you could check the udp[[9] bit has values between 199 ans 202. And so on... Good luck -r On 11/2/05, Hensel, Daniela <[EMAIL PROTECTED]> wrote: > Hi all, > > I have a question that seems to be very easy at the beginning. But after > having a closer look to it, it is not so easy anymore. I hope somebody > has an answer for me?! > > My question is: How can I idenify SIP Messages (or TCP packets containig > SIP messages) to filter them e.g. for QoS? > > I mean, a SIP message has no real header, that says 'This is a SIP > message'. And using TCP or UDP, there is no field in the headers > identifying the protocol that is encapsulated. > > The only idea is to use the default port 5060 for SIP messages (to > filter all messages that use this port), but what will happen, if the > port changes, or if other protocols use this port as well? > > Is there any other possibility to identify SIP messages? > > Thank you very much for your support! > > Best regards > > Daniela > > ########################################### > > This message has been scanned by F-Secure Anti-Virus for Microsoft > Exchange. > For more information, connect to http://www.F-Secure.com/ > > _______________________________________________ > Sip-implementors mailing list > [email protected] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
