Re: [Ethereal-users] XOT dissector doesn't work at all.

[Guy Harris <gharris@xxxxxxxxx>]

On Tue, Sep 10, 2002 at 12:05:43PM +0800, xhz wrote:
> I run "telnet xx.xx.xx.xx 1998", and capture the packet.
> 
> but i found that ethereal doesn't dissect the XOT part of the packet.

Unless you magically happened to type the correct raw bytes over the
connection (2 bytes of 0, 2 bytes of big-endian packet length), there
*is* no XOT part of the packet, there's just a bunch of random bytes
that happened to be sent to port 1998 but that aren't an actual RFC 1613
X.25-over-TCP header.

And, unless the XOT packet has a version number (first 2 bytes of the
XOT header) of 0, the XOT dissector does not consider the packet to be a
valid XOT packet and, in order to keep TCP reassembly from screwing up
dissection too badly, it refuses to dissect the header.