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Knowledge01

VOIP?

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I have a logical school project and I need to setup a phone system for a company. The company already has a PBX system. Should I change that out and put in VOIP with an Asterisk server? Would that be a lot of money? (40-50 users)

This is not real, just a logical project. Anything can help, thanx for the time.

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I have a logical school project and I need to setup a phone system for a company.  The company already has a PBX system.  Should I change that out and put in VOIP with an Asterisk server?  Would that be a lot of money? (40-50 users)

This is not real, just a logical project.  Anything can help, thanx for the time.

Depends on a) the budget B) what they have now c) where they plan to be going.

I know it's just a logical project, but that is always something to look at when doing something like this.

Asterisk is cheap, yes. But not something I would consider *right now* for a corporate environment (just my opinion).

Drop in a Shoretel system if you want to do all voip.

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When doing such experiments, you have to consider the total cost of switching. So this theoretical company has an existing pbx in place to service 50 users. Another question you need to ask is how many of these users can use the system at any one time? If there are 50 users, but only 10 use it at a time, then its much easier than if all 50 need to be able to use it at once. We will assume you need a system with 100% load capacity.

This assumes the company has certain assets.

An analog PBX

2+ T1's comming into the building

50 analog handsets

a shitload of cat3 wire

You'd have to replace the pbx with a few asterisk boxes. I've never dealt in such volume in asterisk, but I don't think you should try to shoehorn this all into one box.

If you want to continue using the analog handsets then you can

A) install an FXS device for each phone in the asterisk boxes

B) get an ATA device for each phone

Or you can scrap all the phones and replace them with all VOIP phones.

And even a third option is to strictly use a softphone system, where there are no physical handsets, and people use an app on their computers as a phone (this assumes everyone in the company has a computer).

If you replace all the analog handsets with VOIP ones, then you are going to have to run a shitload of cat5 cable, and get networking gear to support it. If at this business everyone has a computer, and their computer has a network connection. And now their phone needs one; you have just doubled the networking requirements. So you'll need twice as many switches/routers/etc.

Not to mention the cost of installation and configuration.

in most real life senarios it usually boils down to "if it aint broke, don't fix it."

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If you replace all the analog handsets with VOIP ones, then you are going to have to run a shitload of cat5 cable, and get networking gear to support it.  If at this business everyone has a computer, and their computer has a network connection.  And now their phone needs one; you have just doubled the networking requirements.  So you'll need twice as many switches/routers/etc.

There are quite a few VoIP phones with built in switches for this very purpose. While they are most expensive than regular voip phones, it becomes more cost effective than running new cabling, especially in a large corporate env.

Then get yourself a Powerdsine midspan, and you have data/VoIP/PoE all on one cable (unless you have a fancy poe switch already...)

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Keep in mind that voip-phones with built-in switching require a the switch to support voice and traditional vlans, where many of the legacy devices claim to but do not actually offer functional voice vlan support.

The 2900 series cisco switches for example, they have the command set present but we have never got both the devices functional at the same time on the 2900, the 3500's of course do offer this support, as should most routers but you have to sacrifice a valuable routing port :|

Again, there are always trade-offs.

Personally I am a proponent for the whole 'seperate data-networks, seperate voice-networks', burst-transfers of data on a voice network will totally hose your MOS and hella drop the quality of phone-calls :blink: :cuss:

FXS/adapaters/complete phone replacement are of course the ways to go, with all three being rather costly.

You are not going to see many buildings retro-fitted to VOIP (go sip, boo mgcp and ccgp!!) just yet, they {the network gods.. of whose pantheon i belong?:D} do not have a problem with providing individuals with VOIP phones if their department writes off the cost, but full PBX->VOIP is not a light undertaking if the PBX infrastructure is already in place, especially if unions or regulations end up getting in your way :|

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