A client of mine resells VoIP through several upstream ITSPs. All of the ITSPs use SIP to manage the VoIP communications.
My client needs to manage his clients SIP accounts through the various consoles provided by the ITSPs.
My client would like to host his own authentication service. From this hosted service, my client would like to have the option of routing this VoIP traffic to the preferred ITSP, and use the other ITSPs for failover. The solution should provide redundancy in the case of a single ITSP failure, and would centralize the management of the SIP accounts.
Is there a way (hardware or software) that my client will be able to implement a solution that will allow them to manage their own authentication, and then to relay the communication to an upstream ITSP of choice.
Can anybody please suggest a possible solution?