Sudhakar Godithi: > I have recently started using the ethereal packet capture tool for t.38 > packets decoding. > > I am able to decode the UDPTL Packets ( i.e packets through UDP), > > but i am not able to configure this tool for IFP Packet Decoding( i.e > packets through TCP). > > Problem i am getting is Ethereal not recognising the TPKT Header present > in the IFP, > > Its treating TPKT as IFP starting and decoing the TPKT Header with T.38.
If you'll send some sample captures with T.38 IFP over TPKT over TCP I will try to see if I can fix so that is supported. Currently only T.38 IFP directly over TCP is supported. I have made some changes to the T.38 dissector after the 0.10.0 relase and noticed that TPKT header was recommended according to latest versions of the specifications as I wrote in http://www.ethereal.com/lists/ethereal-dev/200401/msg00085.html : "PS! When I went through the T.38 specification I noticed that in the latest version it is recommended to use T.38 IFP over TPKT over TCP, when using TCP. Currently the T.38 dissector only supports T.38 IFP directly over TCP and also doesn't handle TCP desegmentation. I will try to look into that later, but I have only captures with T.38 UDPTL over UDP (Pre-Corrigendum) and T.38 IFP directly over TCP (Pre-Corrigendum and no segemented IFP packets). If there is someone that has some nice T.38 captures I would be happy if you could send them to me." The T.38 documentation I looked in says: "The IFP packets described in 7.2 are combined with the appropriate headers for TCP/IP and UDP/IP as shown in Figures 4 and 5. In Figure 4, the UDPTL header represents the additional header information required for error control over UDP. To provide interoperability in H.323 environments, the TPKT header defined in RFC1006 shall precede the IFP Packet in TCP implementations as shown in Figure 4. Implementations using TPKT shall set the version to 1 or higher. Note: Implementations of T.38 with TCP/IP transport prior to version 1 were not required to support the TPKT facility." _______________________________________________ Ethereal-users mailing list [EMAIL PROTECTED] http://www.ethereal.com/mailman/listinfo/ethereal-users
