In article <499e0128$0$511$>,
Tim <> wrote:
> wrote:
>> Thanks for the info Tim, we would hope to run a dedicated lease line
>> to the provider is possible. Does any of these provider offer that?
>
>
>You could ask voip.co.uk
>
>A leased line would probably work out more than ISDN30 unless you have
>lots and lots of channels.
>
>At about 2-7 channels, ADSL + SIP trunks is cheaper.
>
>Above this partial PRI probably better.
>
>Then SIP trunks become cheaper higher up again.
I did some benchmarks of 20 concurrent calls over a business-class
ADSL line recently (830Kb upstream), as I've a customer (a small call
centre) looking at moving to VoIP with 20 seats - that required using G729
though. In theory, you can squeeze 34 G729 SIP calls over an ADSL line
with 830Kb/sec upload speed, (or close to 100 using IAX rather than SIP)
however my concern then would be the (ADSL) equipments ability to handle
the packet load - 50 pps each way per call.
>I wouldn't want to be tied to a provider too. I'd buy the leased line
>separately to the SIP connection. Me being me, I'd also buy the leased
>line to my own rack space in a friendly data centre, so I can pick and
>choose my internet connectivity provider.
You may well be tied to a provider if you're registering new numbers
and taking incoming calls, and it might be wise to find out where their
SIP media proxy devices are - some ITSPs may have them distributed in
different data centres and be using load balancing methods to spread
load and increase redundancy... You need to talk directly to the ITSPs
and give them an idea of your incoming and outgoing call requirements.
>Gradwell and voipfone can both provide DSL circuits directly onto their
>networks.
I always wondered about this, but don't have the capacity to do more
investigations right now (nor the need at present). As I see it, you're
either using capacity of an LLU network operator where you can negotiate
with them the contentions, etc. or at the mercy of the BT Wholesale
network as far as I can see it - not sure how to influence the latter
other than pay for elevated service.
>You should also be aware that ethernet circuits are about to have a
>price shakeup, due to the way BT price things changing.
>
>Check out:
>
>http://www.aaisp.net.uk/news-2009-01-ethernet.html
>
>Prices reasonable on the locations I've had quotes for.
There are also deals to be had on traditional 2Mb lines point to point
rather than carrying Internet traffic, (especially if you can go with
someone like Telewest/NTL rather than BT) but if you're doing that,
you might look at running TDM over them rather than VoIP! (30 channels
uncompressed vs. 20) A lot is going to depend on where you are - in a
city with lots of competing operators or in the sticks with only BT )-:
Gordon