Testing ATAs, Gateways, VoIP PBXs, and Other Signal Processing Elements in VoIP Networks

To reliably and efficiently handle voice communications, IP networks contain a myriad of signal processing devices including gateways, Analog Telephone Adapters (ATA), and VoIP PBXs. A PSTN / IP gateway permits calls to be placed between a VoIP phone and a PSTN phone. In essence, it provides a bridge between two different network technologies - TDM and IP. An ATA is similar to a gateway but generally handles a few lines common to a home or small office application. A VoIP PBX may have PSTN connectivity (And therefore gateway functions) or may be totally IP. The diagram below shows these elements in a typical PSTN / VoIP network.