ISDN 2 vs Broadband

[Dave]

What is the actual difference between these two?

I realise they are both faster access to the internet or whatever but is there a physical difference and what are the advantages/drawbacks of each.

[shark_90]

ISDN2 is a pair of digital ISDN lines both at 64kbps.

Broadband is minimum 512kbps and can be sent along an analogue line with the use of a filter to split the analogue and digital signals. "Broadband" in the UK is generally ADSL - A stands for Asymmetric and is called such because it is not the same speed in both directions. With ADSL you have a fast download speed and a slower upload speed.

In Europe it is possible to have broadband over ISDN but I don't think that's offered in the UK?

[Mac]

Shark is broadly right, but there's a bit more to it than that.

You need to look at the application you want to communicate with to decide which is the better medium. For example you can push quality services over ISDN as it can be point to point - that's a lot harder over ADSL.

May be worth addressing this from the other direction Dave - what are you trying to do?

Broadband is great for 'general' data access but it's pretty poor for timing critical applications or in fact for anything that requires guaranteed timely data delivery.

Conversely point to point ISDN2 is great for timing dependent services. Of course you get charged per 64k channel too - which can be painful. I.e. connect @ 64K that's one channel, and one call. Bond 2 x 64k to get 128k and that's 2 concurrent calls. Throw in the 16k extra channel (which to be fair few people support) and the costs can escalate rapidly.

[Tipex]

We use ISDN to link our office computers and radio base station, to a remote aerial on a nice high location, to communicate data and voice to/from all our taxis.

We could use Broadband but the results are poor, ISDN is much more reliable.

[Dave]

We have 3 main sites, all of which are now very busy. We are struggling to manage the number of calls comming into my site, so i phoned BT for some help.

They want to put a switchboard in which means changing the line to twin ISDN 2's.

[nordberg]

Twin ISDN 2's will only give you 4 lines?

[Mac]

Dave, for telephony BT for a site your size it would be hideously expensive.

Can you give me an idea of:

How many extensions
Whether there are PCs at each site
Whether each site has an internet connection
Do you use such things as hunt groups (One number rings multiple handsets)


For a small business with multiple sites with an internet connection I would be inclined to install something like Office communications Server from Microsoft. VoIP interbranch - via the internet - so calls are free.

Telephony gateway which bridges from PSTN to OCS for outgoing calls.

Mind you there may even be cheaper options with things like Asterisk.

What kind of budget were you thinking for this Dave? You could probably do this for 10k ish including h/w I would have thought.

[Mac]

Dave, while I don't deal in smaller stuff, let me have a look at what BT are proposing for you Don't let them palm you off with old digital (non-IP) PBXs and the like.

[Tipex]

We use the BT ISDN phone lines too, we also have 3 sites, one main site and 2 remote sites, all linked together for phones and computers, and trust me on this, if you can possibly avoid using BT then definately avoid them.

We have closed down the local BT Openreach outfit due to sheer ineptitude, and are currently seeking compensation from BT.

[Dave]

Bt are talking about putting in a Versatility system.. just 4 lines (as mentioned above) to begin with but upgradable to 12 should we ever need that many (which i doubt!). This come with 2 x V8 feature phones and a couple of wireless sets.


What i am after is two or more lines on my main number so rather than people get a busy tone they get put through to the 2nd or 3rd line, or get a waiting message.