In reply to a post by kitcat:

You rarely fill to the full capacity so a 100Mb ethernet port usually will max out at around 80Mb.

On a full duplex port, I've had no problems transmitting at 99 Mbps. Main problem is getting data off the disk that fast, you really need SSD

Here's something that might help you out.

Run this command on your Cisco, the output should reveal if you're actually utilising MLPPP:

show ppp multilink

If it's working, you should see a single virtual-access bundle with three member virtual access interfaces.

Only so much help I can give on this, but hopefully points you in the right direction.
I'd be very surprised if BT Business were actually offering this, there's only a few ISPs like us actually utilising this for circuits.

Looks like I dont have mlppp running, i spoke to BT and they said I do have a bonded line but its done by load balancing over the 3 lines. I just cant work out if this is providing me with true bonding, i understand that usually it doesnt mean that but there is config on the ISP end in this case telling their device to route traffic destined for my public LAN IP down the 3 lines equally, does anyone know of a reason why this would not mean i get the speeds of all 3 lines? If anyone works at an ISP id be very grateful if you could explain how your bonding works, providing you offer it.

Are you sure BT said this?
What product is it where they offer load balancing by telling their device to route traffic destined for your public LAN IP down the 3 lines equally?
What device are they using?

If you pick a machine on your network to do a speedtest your router will just pick a line with the best availability and the speed test result will be the speed of that line.

If you ran three speed tests from different pc's then chances are each machine would pick up a different one of the 3 lines.

What you are looking for is one machine to do a Speedtest what the packets be split over your three separate lines so you can see a higher mb/s throughput, but this isn't going to happen as there is no mechanism at the ISP and to do this.

To get what you want all three of the lines need to be combined into a virtual path. To do this you can pay and ISP to host a little fire brick box for you in the data centre. Then you would have a fire brick at your end, and all would be combined as you want.

If you search you can find this on the AAISP website. It specifically tells you they cost for hosting a fire brick in one of their racks. I imagine however that you would have to pay for their data transfer between the fire break and their core network

You need a couple of these, one for the ISP end and one for your end...

http://www.firebrick.co.uk/products_2500.php

Then to host it the AAISP site states,

Special cases
There are some special cases such as hosting your own links to other racks, fibre converters, small FireBricks, etc. Please discuss with sales. For example the ongoing cost for a FireBrick works out to be £15.10+VAT plus bandwidth a month.

Plus bandwidth may be the key point.

In reply to a post by Ripley:

If you pick a machine on your network to do a speedtest your router will just pick a line with the best availability and the speed test result will be the speed of that line.

If you ran three speed tests from different pc's then chances are each machine would pick up a different one of the 3 lines.

Why bother risking it? Just plug each of the 3 modems into 3 PC's and run speedtests simultaneously. No need to risk "chances are".

Yeah that takes the router out of the equation.

What ever he does he's not going to get the combined speed of all three lines on an individual computer to triple the speed test results, unless the set up is changed by including something at the ISP end.

Like this? http://www.speedtest.net/result/3219692669.png

Hello,

Also consider some EntaNet resellers allow MLPPP on their LNS. I have heard of this working with FTTC.

I have three 20CN ADSL1 lines bonded using MLPPP and a Cisco 2821 through an EntaNet reseller.

Much cheaper than using firebricks. Alas with 20CN I do find backhaul contention can be a problem during peak times.