Thanks for this info.  Netcat is a really underappreciated tool. I can't count how many times I've unnecessarily written utilities to send stuff on UDP sockets, forgetting that nc can do it.  -- Alex -- Sent from my Samsung mobile, and thus lacking in the refinement one might expect from a proper keyboard. Alex Balashov - Principal Evariste Systems LLC 235 E Ponce de Leon Ave Suite 106 Decatur, GA 30030 Tel: +1-678-954-0670 Web: http://www.evaristesys.com/Peter Lemenkov <lemenkov(a)gmail.com> wrote:2012/9/13 Alex Balashov <abalashov(a)evaristesys.com>om>: Yep, this command protocol allows us to do tricks like this which is quite helpful for debugging. Unfortunately this particular command ( 'I' and its counterpart 'Ib' ) seems to be broken - it doesn't prepend received random cookie at the beginning of the answer. Just FYI - I collected some examples of control commands here (just grep for ser_proto:decode): * https://raw.github.com/lemenkov/erlrtpproxy/master/test/ser_proto_test.erl and here (which could be even more interesting since it contains an example of a real session - create session, lookup, destroy, get stats, etc): * https://raw.github.com/lemenkov/erlrtpproxy/master/test/ser_test.erl Anytime :) -- With best regards, Peter Lemenkov.