by Charlie Schick

A remote worker is disconnected from the main office PBX. Sure, one can have calls to the remote worker's extension forwarded to the remote worker's home phone, but what happens if the remote worker needs to transfer a call or initiate a conference call? I have seen some PBX over IP solutions that may be the ticket. In this article, I cover vendors that I have discovered who offer such solutions.

First-hand knowledge
I have a quick anecdote to illustrate the need to extend PBX features to remote workers: While working from home, someone rang my extension (which forwarded home), but had dialed incorrectly. I had no means of transferring her to the correct extension. I stammered that I was at home and that she would have to call the office again for the correct extension. I was fortunate that it wasn't a sales-type call. But, what if it was? Requiring the caller to call the main number again is counter-productive. What if I wanted to guide the caller to a specific extension?

PBX over IP
Most remote workers nowadays are connected to the internet or at least to the corporate network. By leveraging this IP connection, enterprises can extend their voice network to these remote workers using PBX over IP devices. These devices connect to the company PBX and connect to the remote worker via IP (either corporate remote access or the internet). The remote worker can then have a phone that can use all the features of the main office PBX, such as message waiting light, caller information, and call transfer.

How it works
Basically, the remote worker's digital PBX phone connects to one end of the device, while the other end connects to some IP network, either via a router or via dial-up (i.e., ISDN, analog). Also, a similar device must be plugged into the main office PBX, depending on the number of remote connections needed. Voice and PBX control information is sent over IP to the device, which hands it over to the remote worker's PBX phone.

MCK Communications
MCK Communications has the Analog Plus EXTender for analog IP access with a 56 Kbps modem. A neat feature of this product is the ability to initiate a PBX Dial Back to take advantage of corporate rates. The ISDN EXTender works over ISDN lines. This device also contains an analog port to use the ISDN B channel with analog devices, such as phone or fax, and a data port to provide a 64 Kbps connection over the ISDN line—voice, PBX, and data in one box. Also, both of these EXTenders have serial ports to allow integration with the PC applications. The third product is the Branch Office EXTender 6000, which extends the features of the corporate PBX to small branch offices. This device supports up to 12 users, has an analog port, and can connect to a wide variety of network termination devices to connect to the IP network.

A software-based solution
Teltone offers OfficeLink 2000, a client/server package that allows a remote worker to use the features of the home office PBX. With this product, a server at the main office connects to the PBX, the LAN, and the phone system. Client software on the remote worker's PC communicates over the IP network to the server to control the PBX features. The audio portion of the call is managed via a regular analog phone at the remote worker's site. Unlike the solutions listed above, this solution does not use VoIP. This solution is also different in that the hardware resides at the main office. This might cut down on support issues due to installation of remote hardware.

Summary
There are a few options available to connect remote workers to the corporate PBX and provide PBX features. The solutions listed here make use of the ubiquitous IP network, which can be accessed via dial-modems or high-speed access devices. If your business has remote offices or workers that need PBX functionality, these solutions will provide the functionality without requiring major duplication or installation of PBX resources. Check them out.