An account is a logical entity usually representing some logical or physical end point in the VoIP network. An example of physical endpoint is SIP phone or individual port in a multi-port device. And an example of a logical end point is a single DID number in a pool of DID numbers received from the Public Switched Telephone Network (PSTN) -SIP gateway.

Each call going through the system is associated with one and only one 'Account'. The Flysip Softswitch establishes association between the new incoming call and some particular Account during the Authentication phase. Once established, this association remains unchanged during the lifetime of the call.

The Authentication could either be performed based on VoIP Login and VoIP Password parameters, using SIP secure digest authentication method, or based on Authentication Rules associated with each account. Please note that the SIP registration with the Flysip Softswitch is only allowed using SIP secure digest authentication.