Hi!
I've improved the layer23 gsmtap support to add support for * uplink frames, sent by layer23 to L1 * properly support dedicated channels with LAPDm * allow the user to specify the GSMTAP destination IP address
In order to use the new features, you need to 1) use the new gsmtap.patch for wireshark 2) use the '-i dstip' option of layer23, as the default is now to NOT generate GSMTAP UDP Packets
I'm attaching a screen-shot showing the wireshark decode of the LOC UPD REQ generated by layer23. As you can see from the packet list, the BTS responds with the UA packet containing the same LOC UPD REQ as part of the contention resolution in LAPDm, just as expected.
Cheers, Harald