Telephone Systems

[rlculver]

Hi all,

As well as looking at a new network, I am also involved with deciding on a new phone system.

I have been looking at ISDN 30, due to the number of concurrent calls need, but have just spoken to a company who says it is really expensive for the initial line rental.

What phone systems are you all using within the educational sector?

Thanks

[Geoff]

Currently in the process of throwing away our expensive BT meridian and implementing Asterisk VOIP.

[localzuk]

Also in the process of throwing away our Toshiba PBX and replacing with an Asterisk VOIP system fed by 2 lines of ISDN2e (4 channels) to the outside world.

Why do you need such a chunky connection to the outside world? Are you getting confused between concurrent internal calls and concurrent external calls? How many lines does your current system connect to?

[paul]

ISDN 30 is only realy benerficial if you are gonna require 8 lines or more coming into the school otherwise stick to ISDN 2e.

[Ric_]

We have an Avaya IPOffice (based around an IP403) with 3x ISDN2e.

We have recently had lots of problems with one of the ISDN lines and with the ISDN card in the IP403 which has meant we were down to 4 channels which proved insufficient for our school.... 6 channels is just enough.

[Tom_ONI]

As Paul says, you need to understand how many concurrent calls you are expecting to make to the outside world.

How many people will realistically be using the phone at the same time? In most schools this number is quite low as a lot of calls are internal.

Also I'm sure you are aware that ISDN 30 or 2e is just the lines coming into the building, you then need a system to run the phone system - be that PBX or VoIP.

I would highly recomend VoIP/IP Telephony if you are going for a new network as you can do all kinds of cool stuff when you combine the two (but I would say that, I sell them)

Cheers, Tom

[Ric_]

@Tom_ONI: Just to clarify your point about making calls to the outside world... remember that you will also have people trying to ring IN and these calls are generally of high importance so you need to make sure you have the capacity.

[Tom_ONI]

Yeah, fair point!

I should have said in and out, just use out as shorthand for outside line, both in and out

Tom

[john]

I have used 4 PSTN lines at one site I used to be at into a Toshiba Strata system (think it was Strata). I have got a Siemens Hipath at one site (total bag of crap that system is, but then again its been butched by the installer and they won't give me the manuals and passwords for it now i've terminated there maintanance on it) and thats fed by 2x ISDN2e, Alcatel Omni-PCX Enterprise at another with ISDN30 on to it and I have a BT Versatility on another with 2 PSTNs into it.

Out of all of them the alcatel gets top marks for speed of installtion, its a 19" rack unit, slot in and plug lines in, plug phones in with normal patches and your done. (yes I know theres more to it IE programing etc) but I must admit I am partial to the BT Versatility as its a nice simple little system.

Currently going VOIP at another site, with a Cisco setup, will wait to see what thats like.

At home i'm just looking into the Linksys SOHO VOIP Wifi Phone System, it looks very good, you need 2 parts to it really, one to get your analog into it (which gives VM as well) and then the other bit for the VOIP and main system part, not cheap, looking at around £450 for the pair, plus handsets which can be wired or wifi but it looks a good idea, just trying to find more reviews on it before I start thinking about change.

[kylewilliamson]

we've got an isdn 30 with 10 channels activated. I was under the impression if you got like 4*ISDN2e you ended up with different numbers - ie: if somebody rings 01234 567890 it would only route down one set of channels.

We've got an LG GDK - might build an Astriesk solution eventually

[john]

I have one numebr assigned to 2 lots of ISDN 2E so 4 channels its assigned on the boxes as 01234 567890/1, 01234 567890/2, 01234 567890/3, & 01234 567890/4

So it will take 4 incoming on that number without issues, I think it depends how they are wired and setup. On those we have 2 DDIs activated.

[localzuk]

All routing of numbers is handled at the exchange - you can have as many numbers as you want to be routed to you over as many lines as you want. For example, if you wanted you could have 6 channels of ISDN - with 10 numbers assigned to them. The BT exchange would just route calls down a free channel and your PBX/Voip box would route it to the correct place at your end as it would be 'tagged' (not sure of the exact technical term) as being a call to a specific number.

[kylewilliamson]

Yes - its Caller Line Identifer (CLI) that does the 'tagging'

The bit I wasn't aware of is having one number assigned to more than one ISDN2e setup.

Kyle

[fonik]

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