The TGM550 is a modular device, adaptable to support different combinations of endpoint devices.
Telephones and lines are connected to the ports on the TGM550 and the TIMs. Different TIMs provide access ports for different types of telephones and lines. A combination of TIMs is selected to suit the needs of the branch. An adapter or switch with Power over Ethernet (PoE) standard compliant Ethernet ports provides support for IP telephones.
The TGM550 supports a VoIP engine that provides voice services over IP data networks. This allows the TGM550 to support telephones and trunks that do not directly support VoIP. The Branch Gateway translates voice and signalling data between VoIP and the system used by the telephones and trunks, as follows: TIMs convert the voice path of traditional circuits such as analog trunk and T1/E1 to a TDM bus inside the Services Router. The VoIP engine then converts the voice path from the TDM bus to a compressed or uncompressed and packetized VoIP on an Ethernet connection.