LAN Telephony

Local access network (LAN) telephony (sometimes called TeLANophy) use LAN systems to transport voice communications. LAN telephone technology is an evolution of voice over IP (VoIP) and the rapid acceptance of virtual private networks (VPN’s) as an alternative to leased line private networks. The ability to share data networks with voice systems offers significant cost reduction for telephone services.

Figure 1 shows a LAN telephony system. This diagram shows that a LAN telephone system consists of LAN telephones, a data network, a LAN call processing system, and a voice gateway to the PSTN. LAN telephones convert audio into digitized packets that are transferred on the LAN to the call processing computer (CTI system). Each LAN telephone has its own network data address. The call processing system communicates with LAN telephones over the same high-speed LAN data network that communicates with computers. When calls are received from the PSTN, the call processing system looks in the database to find the associated LAN telephone address (data address) and this address is used to alert the LAN telephone of an incoming call. When calls are originated from the LAN telephone, the dialed telephone number is passed to the call processing system. This system determines if the call is routed within the data network or if the voice gateway must be used to connect the call to the PSTN.


Figure 1: LAN Telephony