stoofa said:
Well that is the point - you've got no control on what happens between you're two ends of the connection so you've got no way at all of promising any kind of QOS.
Here at the main UK office I'm currently in the process of having a new leased line installed.
We're having a 45MB line put in of which we will be tiered to 8mb.
That is an 8mb leased line, 1:1 contention ratio.
8mb in each direction of bandwidth.
However that is only uncontended so far.
We could have the same in our US office, an 8mb leased line, 8mb of 1:1 contention ratio.
Perfect for VoIP?
A quick trace would indicate that any data flowing from the UK to the US will need to go through routers - there is no magic jump from the UK to the US network.
Unless each of those routers are going to give our voice packets priority then there is no QOS at all.
We could end up making calls with worse quality than two dial-up users using Skype.
Unlikely, but still more than possible.
Your connection to the Internet cannot guarantee anything in the world of VoIP and that is where the problem lies and certainly why we've just invested £25k in what is basically a phone system based on our existing ISDN lines.
We have the ability to move over to an IP system - the system is IP ready and a few box changes and we'd be set.
But right now I just don't see IP systems are really viable - I don't believe there is the return on investment available and you cannot offer the QOS management want.
I think your getting confused with the definition of a leased line, a leased line is a point to point dedicated connection, where you sign an agreement, and the provider will dedicate 8mb or whatever bandwidth on that circuit, you are responible for both end points, the circuit will be switched somewhere in the "clould" but you won't see this. It is a strict point to point connection, you can implement any kind of qos you like. this obviously means that its distance limited usually within a county or where a single provider dominates, if the circuit stretches any further you have to get the 2 isps to agree to transfer it, I've got several leased lines here and they are start off at BT but end up at NTL because BT have no exhange or physical cabling at the B end.
Getting a leased line is usually the same as checking availability for broadband you have to make sure both ends can be installed because its a point to point solution.
If you have a leased line, it is exclusive to you only, thats why its so expensive
When you say "your connection to the internet" a leased line isn't an internet connection, its a physical connection between 2 end points and has nothing to do whatsoever with the internet.
If the distance is too far or a leased line is so expensive, people usually go for a frame-relay solution where a virtual circuit is established between 2 end points, although its switched through the providers cloud all over the place there are still 2 end points.
if you have a leased line which is going from the UK to the US then you have problems, unless you are a carrier or have billions of pounds its impossible to lease any of the fibre which goes under the sea, you cannot have a leased line which is intercontinental.
As far as voip over the internet, i've already said that most people with large scale Voip will get the provider to arrange a managed VPN service where they can use VRF to manage customer VPNs and prioritise traffic, and generally speaking a large organisation will have all their offices with the same provider. It all comes under SLA between the customer and the ISP.
Seriously, if you want to ask a user of the system what their perception of it is, I'll volunteer myself.