Hey all,

First of all let me thanks Neels for his help with the silent_call problem I've been having, which led me to a successful fix.

Secondly I was wandering if I could get a bit more help with regards to ipaccess-proxy this time.

Now that silent_call is working I want to start manipulating traffic and do some fuzzing. I understand that the ipaccess-proxy is the right tool to use, but I don't seem to get it working.

In my current NON ipaccess-proxy setup (which works) I have an osmo-bts which gets data from a USRP B210 via osmo-trx-uhd. On the same machine I also run the osmo-osc. I have configured the OML remote address in the BTS (bts 0 -> oml remote-ip) to a unique localhost (127.0.127.1) and the BSC to listen on that (e1_input -> ipa bind 127.0.127.1).

What I want to do is interleave the ipaccess-proxy on this connection (e.g. receive OML from BTS on 127.0.127.2) and forward to the BSC on 127.0.127.1. I have successfully managed to make ipaccess-proxy bind to the specific address (by changing the default IP binding from 0.0.0.0:3002 and 0.0.0.0:3003 to 127.0.127.2:3002 and 3003), and I am receiving traffic from the BTS. However, traffic is never forwarded to the BSC. There seems to be some issue with unrecognized IPA message types.

Would anyone be able to provide me with some insight, or perhaps a setup in which ipaccess-proxy worked successfully?

I'm also not clear on what ipaccess-proxy is supposed to do. Is it a sniffer (since it binds on 0.0.0.0 by default) or is it a "MITM" relay type of software.

I am attaching the output log I get from ipaccess-proxy.