Wireshark-users: [Wireshark-users] DNP3 message spanning multiple TCP packets bug

From: Graeme Melia <graeme.melia@xxxxxxxxxxxx>
Date: Tue, 05 Jul 2011 21:42:20 +0100
I am using Wireshark to to monitor a multi-serial port device that
communicates to a server via IP.

The outgoing TCP messages from the server has the DNP3 message embedded,
usually in one packet.

The incoming DNP3 messages are being broken up so that each byte is a
single TCP packet, or a 23 byte DNP3 message becomes 23 TCP packets each
with a payload of 1 data byte.

The problem is that the Wireshark DNP3 dissector is not reassembling the
original DNP3 message.  I have checked the DNP3 option to reassemble
messages split across multiple TCP packets and the TCP setting to allow
subdissector to reassemble TCP streams.

Is this a bug or have I missed something?