1.2.2 Registrar

A registrar is a SIP server that accepts REGISTER requests from clients and places information about clients into the location database. When a request, for example an INVITE, is addressed to a registered client the softswitch looks up in the location service and learns how to communicate with the client, i.e. it gets its IP address, port and transport protocol.

The registrar role is crucial in retail services where clients connect from dynamically assigned IP addresses. The client has to refresh its location by sending a renewal REGISTER request at intervals determined by the registration expiry time. The location information is stored in the application memory. If you want to share it with other voipswitch instances working in a cluster or use the data by a 3^rd party application, you have to enable the cluster mode in the voipswitch_conifg.xml file. The current location data is stored in the database in the registeredclients table.

The voipswitch registrar server supports UDP, TCP and TLS protocols.