How does office based VOIP work?

[cpvh]

Sorry, me again.

I probably won't wind up messing with the VOIP side of my friend's wiring, except possibly to repatch handsets from one place to the other. However, I am now interested in learning more about this subject "for the fun of it", but am frustrated as I can't find much info via Google. (all I get is info on how to use SKYPE on a home computer!). So.....

How do these things usually work?

At my friends place, my initial assumption was that the box where all the handsets run back to had connections to either POTS or ISDN lines which then carried the Voice calls via BT's network to their destination.

Reading the marketing blurb from a couple of companies offering VOIP to small to medium sized businesses, I am now coming to the conclusion that what actually happens is that the VOIP traffic from the handset is switched via the box to dedicated ISDN circuit(s) which then connect direct to a Telco who then routes the traffic through to it's final destination in whatever way they see fit

Am I on the right lines?

[Rob Morley]

You might find a clue in the name - IP = Internet Protocol

[cpvh]

Er yes, and TCP = Transport Control Protocol, but that doesn't tell me whether the box talks ip to the handsets and then ip to the Telco, or if it talks ip to the handsets and uses Analogue lines to talk to the BT network.

[Sparks]

VOIP is Voice Over Internet Protocol.

Internet Protocol, or IP is the protocol used in most networks (all internet connections are IP surprisingly :-) )

The VOIP part of the call could only be internal to the company with a VOIP server, like Asterisk, this VOIP server decides (is programmed) to route the call form there.

So the call from the desk phone, or soft phone on a computer is routed from that device to the VOIP server via a normal data network as apposed to the traditional analogue pair of wires from each phone to the telephone system.

The VOIP telephone system just has one connection to the office network, so does not care where every phone in the building is located. Usually when someone moves desk, the phone system would need to be reprogrammed to route the correct telephone number to the appropriate desk - With VOIP you just move the phone with the user and plug it in to the network - the VOIP server does not know it has moved, nor cares!

The user could also be moved to another building, and their phone could still communicate with the VOIP server over the internet or via private circuits.

Once the call has got to the VOIP server, then this server can be connected to any telephone service you like, ISDN, POTS, Cell, Satellite, etc..

If the telephone system has access to an internet connection, it can connect to other VOIP providers, either commercial, or even another VOIP server in another office (calls between private VOIP servers would be free of call charges, you would just need them both to be connected to an internet connection.

Sparks...

[.]

you talk to the handset which talks to the box which does the ip to ip bit and your voice comes out the other end. how, exactly, that happens is dependent on your setup.

[Andrew Gabriel]

Try reading or asking in uk.telecom.voip

[cpvh]

Thanks Andrew, (and as with my thanks to Sprks the other day, that's genuine thanks and no critiscism of your reply is meant by any of the below, i'm just rambling) I did find that group, and will prolly follow it for a while. I didn't ask them, as I often find that popping up unexpectedly in groups (present company excepted) with newbie questions often doesn't get much responce or gets a hostile responce.

WRT Google, we often refer people to Google, espescially when they want to know if they can add a spur to a ring circuit, or how to attach a x kind of hob and x kind of oven to a cooker point, but I am finding that even if I know that the threads are on there, it can be a bu**er to find em.

Perhaps we should get in the habit of some here of giving a link if we know there is a specific thread (which we knowing just the right combination of keywords) can prolly find easier than Mr newbie.

Then again, if we all answer again, we might make a new friend and learn something new along the way.

IMHO, listening to Matthew (one time owner of this group) was worth the licence fee on it's own.

Ah, happy days.

We often suggest to people pos

[Mark Scott]

Not really. Wikipedia is your friend here; try

[Rick Hughes]

I work for a company that is No.1 in IPT, (IP Telephony) which uses VOIP as the basis for carrying the data ... but IPT is a lot more than just using a CODEC to digitise the vouce and then transport using TCP/IP. protocol.

If you want I can email you a book "VOIP for Dummies" it is in the style of "Windows for Dummies etc.", it is a pretty large pdf file.

Send me a direct mail if you want a copy.

IF you have any specific questions on VOIP drop me a mail.

Rick

Rick

>

[The Natural Philosopher]

I think both are possible, but the routing of calls menas its notasy to do end to end VOIP.

Typically VOIP stops and goes 'ordinary' either at the router, at some public service router, or it uses something like skype to do the rest.

I.e. once outside our own network, you need a third party at some point.

In general its use in the office is to halve the number of wires, and thats it.

[Richard Conway]

I wouldn't say that's the only reason. It is also very convenient to be able to route all voice and data over the same network - especially in an environment where people regularly move around the office. For instance, in a conventional set up, individual extensions are connected to individual ports on the switchboard, so if you currently have extension x in a particular office and want to move it somewhere else, it will need to be re-patched through from a patch panel. In a VOIP set up, its possible to have every RJ45 socket in the office capable of accepting any phone - as it is the phone itself which determines the extension number, not the port it is connected to.

[The Natural Philosopher]

Its possible to put call forwarding on a stock PABX from an extension, and to reprogram the PABX to switch extension NUMBERS between hard wired extensions, but I accept that simply pulling the phone out of one socket and plugging it into another is indeed useful..not that people who skip from office to office ever do that except on the basis of ESCAPING phone calls...;-)

[Richard Conway]

Ah, in our office we regularly carry out "permanent" moves (the inverted commas are there because it happens so frequently that nobody is really permanently anywhere!) It is a PITA at the moment as we have to change all the lines over at the patch panel so everyone is on the right extension. Would be nice just to be able to move the phones and be done (as we can with network connections to the PCs)