Steven wrote:

>
> We were thinking about a move to VoIP. Is this feasible for a business with a measily 10 lines or so, or is the business

Less than 10 lines is probably the sweet spot for hosted VoIP installations.


> Easily achievable, or should we stick with ISDN?


You have 2 questions.


1) to have ISDN or not have ISDN

And if you don't have ISDN:

2) to have a IP PBX onsite, or just use a hosted provider.


If you really need 10 lines, then you aren't going to get enough
bandwidth on a normal ADSL line to support 10 calls. (well, not without
dodgy compression which won't sound so good)

In the VoIP world, lines are a bit washy. I've spoken to lots of people
who only have 4 people in their office, but have 10 phone lines on an
old system. They don't want to risk that an inbound call will get a
busy tone, rather than hitting the voice mail or call queue. If you go
hosted, you effectively have unlimited lines into the hosting provider.


Is your traffic mainly incoming calls or out going?

Jono suggested mixing and matching. This is easily possible if you have
an IP PBX onsite.

For instance, you could take 4 channels of ISDN from BT to use for your
inbound calls, and put all your outbound calls out through a SIP
provider. This could save you a loads of ISDN line rental, but still
leave you with a backup channel to the outside world.

On the other hand, if you are at the level of getting ISDN30, then
channels don't cost that much anyway.

Tim