Advice for building phone system for private school

[completelyhis]

The private school my boys go to (and my wife teaches at) finally got occupancy of their new facility. I told them I'd be very interested in consulting with any tech questions, and I've been able to help with network and a few other things. They recently asked me about phone systems. My first thought was that they could benefit from having a pbx system with ability to have auto attendant, voicemail, hold music, paging, call xfer/park, etc. I'm thinking about voip too, though, so I'm not sure.

They have 1 office building and currently 5 modular class buildings, with 3 class rooms in each modular. My guess is the office building should plan for 3 or 4 extensions. I'm not sure if they want one extension per building, or per room.

There are apparently some large conduit chases daisy chained from the main office to the modulars.

I'd like to put together a presentation for them based on voip vs pbx. If there are any other technologies out there I don't know about, I'd be interested in that too. My presentation will include:

cost (new compared to used)
features
expandability


I'm not sure where to start, so I'm looking to get pointed in the right direction in my research/thought process.

thanks!

Ian

[sjcato]

Asterisk seems pretty popular for homebuild systems, and works with both VoIP and POTS lines. The software is free, and low spec so can be set up on an old PC.

http://www.asterisk.org/support/get-started

[michael.davis]

I have 35+ years of telephony experience, with 20 as a hands-on tech, manfacturer's product support manager, new systems design manager, and industry consultant. I've watched the changes in technology closely and have implemented and used VoIP systems in recent years. I have formed the following opinions that might be helpful to you.

1. For reliability and quality of communication nothing compares to conventional "copper" telephony. The infrastructure that has evolved over the last 100 years is quite stable, reliable, and well understood by all the technical folks involved with telecommunications. In all cases there will be dial tone on the phone lines, up to the building or demarcation point, unless those specific wires have been cut by some accident. The power is provided by batteries located in the local central office, supplemented by generators (typically on the roof) to assure continuous communications regardless of weather or other power-affecting situations. If the customer has a conventional phone connected to those wires there will be dial tone to call for help. In the case of PBXs, the customer has the option to install back-up power to the system to maintain service under the same circumstances. PBX hardware is very affordable, and there are numerous vendors to service most manufacturer's products in most geographical areas.

2. VoIP is about economy, period. Because VoIP communications shares infrastructure and bandwidth with data users, and that infrastructure is not as reliable, or manageable, as the voice infrastructure, quality cannot be assured or assumed. My personal experience using VoIP in a commercial setting is that the calls never match a pure telephony call. At best the quality is acceptable, at worst there are dropouts, stuttering, frequency shifts, etc. that make it difficult to "just talk". From a reliability perspective, the devices that manipulate the packets of voice from the client's phone to the telephony network do not have the same ruggedness as pure voice. There are routers, firewalls, and many other pieces of electronics along the path that affect reliabilty and quality. Most are managed, but none have the same quality design characteristics as pure voice devices. If there is a power failure anywhere along the path it is likely to interfere with communications, if there is a fail-over strategy for the network that re-distributes traffic when segments are impacted the design choice is to degrade service for all users so that everyone shares what bandwidth is available. Finally, VoIP vendors and technicians do not have the depth and breadth of experience to maintain high reliability and quality. The economics of VoIP, and all the competition for those dollars, means that techical training and skills will never be as good as conventional voice equivalents.

When explaining the importance of reliability we used to make this comparison: in a commercial setting, if the PBX goes down the company is calling for help in minutes; if the data network goes down people will go on with their business and wait for the network to come back, sometimes for hours. Telecom equipment and support was designed for that environment, VoIP is not.

I would never implement VoIP in an environment where telecommunications is important. The addage "you get what you pay for" truly applies in this area at this time. There may be a time in the future when the infrastructure and support bring VoIP closer to pure voice, but that time is not now.

Hope this helps you in your planning.

Michael

[completelyhis]

It does help quite a bit, thank you Michael for your advice!