VOIP is a compelling technology because it can be integrated with existing PSTN technology, or can be deployed standalone utilising a pure IP back-haul for communications. This article will explore how VOIP can be integrated with existing PSTN technology or be deployed in a standalone environment.
The Office Communication Edition can be configured with a PSTN interface card that will allow it to make and receive telephone calls using phone lines provided by the telephone company. There are two types of PSTN interface cards, Plain Old Telephone Service (POTS) cards and Primary Rate Interface (PRI) cards. POTS cards interface with analog phone lines, such as those found in a typical residence, while PRI cards interface with a bank of digital channels, usually 24, carried over a T1. When deployed with a PSTN interface card, the Office Communication Edition can integrate PSTN with VOIP technologies.
A typical office configuration is shown in Figure-1, and uses the Office Communication Edition and multiple VOIP handsets all connected to the office LAN. The Office Communication Edition is also connected to the PSTN using a PSTN interface card. With this configuration, incoming calls can arrive from the PSTN, and be received on an IP handset, directed to another office with a Office Communication Edition, or forwarded to a user's cell phone using a second PSTN line. Local outbound calls can be routed to the PSTN over the interface card, and long distance calls can be routed over the internet to take advantage of cheaper rates.
The Office Communication Edition can also be deployed in a pure IP configuration. An Internet Telephony Service Provider (ITSP) will be used to receive incoming calls, and place outgoing calls, as shown in Figure-2.
The Office Communication Edition is a flexible communications platform that can be deployed to suit your business' telecommunications needs.