Thank you..

in fact, last night I did a hack, and it started to work http://www.opensigtran.org/bsc.html

I'm doing without osmo-bsc_mgcp at all: after a chanel is being opened, my transcoder just replies the first rtp from bts and keeps this address as endpoint.

I was about to clean the code (my ss7+ca and transcoder), publish it as well as discuss patches/hacks to openbsc I had to do:

1) in my case, OpenBSC makes BTS to talk to a predictable port at transcoder

2) I could not guess your reasons (as well as ways) to configure voice codecs within BSC, and hardcoded them within bssap_handleassingm_req()

Hope to prepare a proper letter it in about a week

BR,

Dmitri

On Mon, Sep 2, 2013 at 2:57 PM, Holger Hans Peter Freyther <holger@freyther.de> wrote:

On Sun, Aug 25, 2013 at 07:03:40PM +0400, Dmitri Soloviev wrote:
> Thank you
>
> but there are few things still unclear:

> - why at A-bis interface BSC issues ip.accessMDCX with ip=0.0.0.0? is there
> anything configured improperly?

that is okay. The BTS has the OML/RSL connection. When the BTS is
receivng a 0.0.0.0 on the RSL link, it is supposed to send the RTP
to the IP address of the peer of the RSL link.

> - so, UDP port is BSC side is predicted. but an endpoint at BTS side is
> dynamically allocated.. is there a way to inform osmo-BSC_mgcp, or it just
> replies to RTP from BTS?

right. The osmo-bsc_mgcp will open two ports for each endpoint. One is
facing toward the BTS and is predicatble, the other will be dynamically
allocated and faces the network.