The customer is one of the leading mobile operator in Israel.
Presence server. The customer had an old SIP platform with no presence support.
We’ve built two services, an API service and an opensips sip presence server.
Together with the customer dev team we built an API that get notifications from the core SIP server and push them to an opensips server.
The opensips server handled all the subscriptions and notifications from the sip endpoints.
When an endpoint boot up it subscribed to the opensips to get notifications(BLF) of other SIP endpoints, the opensips communicated with the API service and get the endpoints statuses and send notifications to all subscribed endpoints, also, every new notification from the core server was translated to sip via the API and opensips and sent to the list of subscribed endpoints.