A media gateway is essentially a translation device that converts communications between disparate networks and protocols. The following are a few common examples of media gateway uses:
Connecting a UC platform to the PSTN (SIP Trunk, T-1, PRI, analog)
Connecting an analog or digital PBX to the PSTN (SIP Trunk, T-1, PRI)
Connecting an analog or digital PBX and VoIP PBX
Connecting an IP-based phone system to the PSTN (SIP Trunk, T-1, PRI, analog)
Connecting a legacy PBX to a UC platform like Microsoft Lync or OCS
Creating survivability and PSTN failover in remote offices
Supporting existing IP Phones in a UC platform like Microsoft Lync or OCS
Connect IP telephones to a legacy PBX
Extend a PBX to branch offices
Creating fax and legacy analog support for UC platforms and IP PBXs
Image courtesy of AudioCodes.com
PBX - Private Branch Exchange; a telephone exchange that serves a particular business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public
PSTN - Public Switched Telephone Network; the network of the world's public circuit-switched telephone networks.
PRI - Primary Rate Interface; a form of ISDN (Integrated Services Digital Network) line which is a telecommunication standard that enables traditional phone lines to carry voice, data and video traffic, among others.
UnifiedCommunications.com can help you select the right gateway with products from leading manufacturers like Audio Codes, Dialogic, NET and more.