Ethereal-users: [Ethereal-users] T.38 packet

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From: "Todd Huang" <[email protected]>
Date: Wed, 20 Oct 2004 11:53:55 +0800

I tried to use the Ethereal (ver. 0.10.6) to analyze the captured T.38 traffic. Although the Ethereal could recognize the T.38 packets, each packet was interpreted as [Malformed Packet]. Please see the attached file. I don't know whether the T.38 packets were really incorrectly formated, or the Ethereal didn't know how to interpret it. Besides, some of the packets were
interpreted as [UNKNOWN PER:]. What did it mean?

   By the way, I has the following questions about UDPTL header format.

1. According to the T.38 (2002) ASN.1 notation, the item follows the seq-number of the UDPTL packet is the primary-ifp-packet. Why the item next to the seq-number was interpreted as
    primary_ifp_packet_length by Ethereal?

2. There are two error recovery methods (FEC & Redundancy) used for T.38 over UDP transportation. From what item or field could we know which method is used?
   Thanks for your kindly help.


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Attachment: t38_analyze
Description: Binary data