On Tue, May 15, 2018 at 04:49:01PM +0300, Mykola Shchetinin wrote:
We are going to write a simple proxy which converts
from GSUP to MAP
and vice versa.
GSUP was/is specifically intended to be a simpler subset of MAP that should be
easily compatible with MAP. An Open Source MAP proxy to SGSN exists, if that is
of interest to you:
https://github.com/moiji-mobile/sgsn-mapproxy
Anecdotal: GSUP came about because we wanted to connect osmo-sgsn to a 3rd
party MAP. I wasn't around at the time, but as far as I understand, we invented
GSUP to have a less complex C implementation that talks a leaner protocol over
an expensive/slow link, and to convert to MAP closer to the core network and
talk to the third party HLR. It was first called "GPRS Subscriber Update
Protocol". Now we've started to use the same to talk between osmo-msc and
osmo-hlr, and interface osmo-sgsn directly to osmo-hlr, hence now we renamed it
to "General Subscriber Update Protocol".
So your plan indeed matches what above sgsn-mapproxy was intended for. I'm
personally not familiar with MAP though, not sure what effort might be required
to proxy for CS as well. And it's written in SmallTalk.
...just thought I'd mention this.
Is your MAP proxy going to be Free Software? Since Osmocom lives from
contribution, we would highly welcome you sharing your progress and code base
with the Osmocom community. (It might even be hosted by osmocom.org??)
~N