You need three key pieces of VoIP hardware to make use of a VoIP calling plan. The first is an analog-to-digital phone converter such as the Cisco ATA 186 which is also known as adapter. This device converts analog signal into digital data, which can then be transmitted over the Internet.
The second is the router. The router checks the destination IP address, and routes the digital packets through different paths on the net. The router does this to avoid congestion or buffering, which may lower voice quality.
The third is the phone itself. The subscriber can use his existing analog phone and attach it to the adapter which will convert the analog signals to digital data or else buy integrated IP phones, such as Nortel’s 12004 Internet Telephone, Cisco’s large line of IP phones, or Adtech’s SI-160 IP Phone. These phones can be plugged directly into the broadband cable or DSL lines.
The hardware used at the company end is more complex. The most important is the gateway. VoIP companies have the option to install the gateway devices developed by RADirect, which allows data to move across IP networks; MultiTech’s MultiVOIP gateways, which support both SIP and H.323; or Cisco’s carrier-class VoIP and Voice over ATM (VoATM) MGX 8000 Series Gateways. Besides this, MultiPath switches are needed to integrate a gateway, gatekeeper and intelligent call routing; to route calls between the IP network, PBX and PSTN lines; and to route calls between different IP networks.
This is a complex range of hardware and is operated by a team of specialist engineers. The hardware has to be constantly upgraded whenever a new device hits the market or when the network reaches saturation point, and has to be scaled upwards.
Some of the VoIP hardware devices also require special software to be installed. A good example of this is Cisco’s VoIP products, which require the Cisco’s Call Manager software to be installed. However, there are also several hardware devices that are compatible with different VoIP services.
Much depends upon the basic architecture. This has to be designed carefully to deliver good returns. Fortunately, there are several hardware options available today and a VoIP phone company can pick and choose its hardware to deliver the best results.