Telecommunications System

The LHC presently uses Conversent as it's telecommunications carrier. There are three telephones, two in the office and one upstairs, which share two lines. We are looking into a new system, and the following is a very preliminary outline of a possible system.

The new system would be VoIP based (Voice over Internet Protocol) using Asterisk (http://www.asterisk.org), an open-source PBX. The system runs on a PC running linux, and we already have a sufficient machine for the job. The system has the following features:

• DID (direct inward dialing) phone numbers for everyone
• Interactive voice response and routing
• Voicemail, including emailing voicemail messages, forwarding, etc
• Ability to use wifi phones throughout building
• Intercom and conference features
• Call-forwarding to home or cell phones
• Ability to call from home through LHC to make long-distance calls
• Each PC will have a software phone
• Leverage Ethernet wiring for phone system

The Asterisk system will allow us to use existing POTS (plain old telephone sets) if we want, or inexpensive ($50) full-featured voip phones to access intercom, conferencing, forwarding, and other features.

The cost of the PBX is essentially free, since we have the hardware and the software is open-source. We will need an analog interface adapter to use POTS phones, or (better) buy voip phones as needed.

There are voip phones which work over the wifi connection, and are as small as a typical cellular phone. These phones will enable staff to carry the phone with them around the building and have access to all of the system features as if they were at their desk phone.

If a voip phone is taken to a staff/volunteer's home and connected to their network (either wired or wifi) they would be automatically connected to the phone network as if they were still at the office. In this sense, a voip system nicely supports a distributed organization.

Another compelling advantage of VoIP is that the telecommunications cost is a small fraction of the typical business carrier rates. (eg. 1-2 cents/minute anywhere in the world.) And the cost based entirely on use - no high fixed monthly charges. Also, it is possible to make point-to-point voip calls at no cost. So, for example, several volunteers could work on a project at home on their PC and 'open' a PC-to-PC voip connection and stay in communication the entire time (all day if needed) for zero cost.

Once disadvantage of VoIP is that the phone connection is lost if the power fails. This has implications in an emergency or for the fire/safety alarm. For this reason, it might make sense to keep a single voice-line with the lowest cost metered plan.

We are assembling and testing an Asterisk server now, and will be able to demonstrate the system at LHC sometime in Q1 08.