Wireshark-users: Re: [Wireshark-users] Dissector for ANSI TCAP NATIONAL code:0 notimplemented.
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Thu, 03 Jul 2008 10:07:35 -0700
Anders Broman wrote:

If the request isn't in the trace it's not possible to decode the response
as the command code is unknown(not present).

Presumably in that case the dissector would indicate that the command code is unknown because the corresponding request isn't in the trace, not that there's no dissector for the command code. (If not, that needs to be fixed.)