Remember, though, that RFC 3261 is talking about Path MTU, rather than Link MTU, so the MTU in question could be lower than 1500 even if the first hop is over Ethernet.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Michael Cohen Sent: 10 April 2006 16:54 To: 'Kishore Sowdi'; [email protected] Subject: Re: [Sip-implementors] sip msg length ...... > Hi , > _____________________________________________________________________ > > rfc 3261 , section 18.1.1 says > > "If a request is within 200 bytes of the path MTU, or if it is larger > than 1300 bytes and the path MTU is unknown, the request MUST be sent > using an RFC 2914 [43] congestion controlled transport protocol, such as > TCP". > > My interpretation of the above condition > > If ( (SIP msg len < 200 ) || ( SIP msg len > 1300 ) ) > send over TCP. For messages smaller than 200, you probably want to use UDP. Here's my interepretation of rfc 3261 , section 18.1.1: If ( (MTU_is_known && (SIP_msg_len < MTU - 200) ) || (!MTU_is_known) && (SIP_msg_len < 1300) ) { send over TCP } For more on the MTU (maximum transmission unit) see RFC-1191 The MTU for Ethernet is 1500. > > Is my interpretation correct ? . > _____________________________________________________________________ > > thanks & regards, > Kishore sowdi. > > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
