Re: interfacing core network to SIP world

On Mon, Aug 05, 2019 at 04:27:56PM +0200, Keith wrote: Changing to an IP protocol reminds me of jolly's proposal we talked about in december, a kind of all-new osmo-sip-connector-and-more called osmo-cc. Can't seem to find a mail reference to that ATM... I haven't heard about it since December, but even if nothing has happened, would probably be worthwhile to take a look at the protocol that jolly already has mapped out in pretty high detail. The point is that the unix domain socket connection can take assumptions that the other side is on the same CPU and simply dump (packed) data structs into it, being sure that they come out intact on the other side. If we're talking UDP there should instead be a well defined protocol involved to properly encode and decode different sized integers (and so on and so on). Simply pasting the current mncc structs into UDP would be a pretty bad hack that is guaranteed to be unportable. Related, if I'm going to incorporate proper SDP codec negotiation in the osmo-sip-connector, I should probably keep that modularly separated from the unix domain socket protocol, and we should coordinate with this idea. Yes, these are leftovers of the OsmoNITB paradigm, being "I am the entire core network". If a subscriber isn't attached, it doesn't exist. You are right that there should be a distinction between "exists" and "is currently attached", and the latter part is simply not implemented. I'm currently not sure what 3GPP spec'd mechanisms the MSC or VLR have to query the mere existence of an unattached MSISDN, but you're correct to assert that that is missing. ~N