[SR-Users] Re: lost module: best practice handling delay caused by held / lis procedure?

Hi Sergey Swisscom is operating all the emergency call infrastructure in Switzerland. Most documentation is public: https://www.swisscom.ch/en/business/enterprise/offer/alarming-solutions-eal… Referring to this document: https://documents.swisscom.com/product/filestore/lib/851d8bf5-d686-4a41-990… Swisscom is operating the ECSP consisting of LIS server, where we as TSP (VSP) push the location information (postal address) for en emergency call and the LIS Proxy, where the PSAP de references the URL. So, when processing an emergency call on kamailio, I have somehow to get the location information to the LIS server. Kamailio offers a service to our customers, for this it does not need to know the postal address of the caller. But it holds a reference to the calling customer (also used for billing and all sort of stuff). Let's call it the Customer ID. So a registered customer is calling 112. What Kamailio does: * Authenticate INVITE (getting customer ID linked to authentication username) * Pull more information from the customer profile like barred numbers sets, and a location ID (now using the zip code but about to extend this for better accuracy and handling some exceptions like large industry complexes that have an own fire brigade). * Perform Lookup in local Database (could also be a textdb): Emergency Number 112 + postal code. Result: Destination PSAP Phone number! So at this point we are fine, we know how to route that call to the appropriate closest PSAP. But with NG112 we have to set a Geolocation header to indicate the exact postal address and building ID (EGID) to the PSAP. Legacy Mode: PSAP looks up the address of the calling phone number in the 'emergency' directory service, also operated by Swisscom. But this has to be actively updated via a cumbersome API by all telephone operators and I guess this does not work at all with some operators. So pushing the location with the call is for sure the right way to go. So my intention was: modparam("http_client", "httpcon", "heldsrv=>http://localheld.example.com/api/held"); $var(id) = "$var(customerID)"; $var(res) = lost_held_query("heldsrv", "$var(id)" , "$var(pidf)", "$var(url)", "$var(err)"); if ($var(res) == 200) { append_hf("Geolocation: $var(url)\r\n"); } else { xlog("L_ERROR", "HELD locationRequest for $var(customerID) failed with status: $var(res)\n"); } On that local held server, the postal address linked to the CustomerID in question could be looked up and pushed to the Swisscom LIS Server which then returns the URL which the local held server is passing back to me as the reply to the lost_held_query. Am I doing this in an overcomplicated way? Mit freundlichen Grüssen -Benoît Panizzon- -- I m p r o W a r e A G - Leiter Commerce Kunden ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 00 CH-4133 Pratteln Fax +41 61 826 93 01 Schweiz Web http://www.imp.ch ______________________________________________________