SUA on-link cb?

Neels Hofmeyr nhofmeyr at
Mon Apr 4 15:55:50 UTC 2016

On Mon, Apr 04, 2016 at 04:09:05PM +0200, Harald Welte wrote:
> Please check the ITU specs for SCCP, specifically the N-CONNECT
> Figure 8 of Q.711 should give a good idea.

I see those specs, yet it is hard to put them in practical perspective.

My point is, I don't see N-CONNECT primitives in wireshark. So it seems to
me there's no use hooking on those  ... or is it because the osmo sccp
code simply fails to do that negotiation?

When I place debug output (using printf to make sure debug log levels
aren't disabled) in the N-CONNECT prim rx code in osmo-hnbgw, I also don't
get any hits when connecting omso-hnbgw to the CN.

Assuming osmo-sccp is working correctly, I'm pretty sure the N-CONNECT
doesn't help in sending a Reset from omso-hnbgw to the CN upon connecting.

I already have the on-connect callback implemented as described before,
which does register when connecting to the CN. So I'll commit it on
libosmo-sccp branch sysmocom/iu and use that to send a Reset.

I wouldn't really want to get side-tracked from the side-track, but it's
not set in stone: comments welcome!


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