Improve Speed of Cable Modem With connection Setting

At NetWorld+Interop 2001 I found an interesting piece of software called MidPoint from MidCore Software. Midpoint has a feature called ‘connection teaming’. Connection teaming aggregates multiple connections to the Internet for increased bandwidth. Along with connection teaming, the software splits large files being downloaded into multiple smaller parts and downloads each part at the same time along each connection. Wow!

I came up with this idea for cable modem users. Cable modem companies sometimes allow you to purchase additional IP address’ for a monthly fee. @Home does this for $5 per IP address. @Home caps your bandwidth per account, not IP address - but at the very least, it might increase the efficiency of your conenction and allow your throughput to closer reach your capped maximum speed.... So I set off to test my hypothesis.

Planning the network

Because I would be testing the aggregation of 2 Internet IP address, I needed a computer that could handle 3 network cards – three for the WAN and one for the LAN. A stripped down Pentium 233 fit the bill nicely.

Problems with the testing

One of the biggest problems in testing this setup is finding a way to push the speed of the cable modem. To do this, I had to find some servers willing to let suck up a whole lot of bandwidth without running into something that would throttle my connection. This is VERY HARD to find. My best performance came from some TUCOWS.COM mirrors. Since TUCOWS is mirrored all over the country, I was able to locate some servers willing to let me suck up some bandwidth.

Measuring Bandwidth

The next thing I needed was a measurement tool. IE’s meter on the download is good for measuring speed because it averages things over a long period of time and does not allow you to ‘see’ what is going on. MyVitalAgent was a good solution because I could see how solid the connection was. If there were major connection pauses I could see them visually – plus the software is free!

Bandwidth measurement on the Internet is not an exact science. It is impossible to recreate the exact conditions across a public network. Because of this, I chose to measure bandwidth at its peak if sustained for 10 seconds or more. To do this, I chose files of no less than 5Mb to download.

How Fast?

For Reference, I tried pushed each if two IP address’ individually first. IP address A gave me about 840kbps sustainable bandwidth and IP address B could give me about 600kbps sustained bandwidth. I was surprised at the difference since they were from the same cable modem - They did however have different default gateways and were on different subnets. These speeds will of course vary betweed service providers. Notice that my speed is capped at 1.4~1.5 but my throughput is unstable and reaches only about 850kbps.

With connection teaming enabled, I was able to sustain speeds of 1300kbps, or 1.3Mbps when downloading multiple large files (note, the cap is still 1.5Mbps). This is not bad for a single cable modem! In addition, web page surfing seemed to ‘spring’ to life. A single web page might require 7 or more requests for text and graphics. When these requests are being done over two different IP address response time improves dramatically. This does not push your 'throughput' but it does make web pages come up faster due to the increased network efficiency.

IMPORTANT: The Key is the Subnets

They key to my success seemed to be in the fact that the two tested IP address’ were on different subnets with different default gateways. I tried running the same test on two IP address’ that were on the same subnet / same default gateway and had almost no improvement. This is a VERY important note. These tests were done with STATIC IP address.

ATTN: @Home Users

When you sign up for multiple computers, you are getting multiple IP address' - STATIC ONES! Instead of setting your computer name, set IP, Subnet, default gateway and DNS servers manually. You can get all that information from this @Home networking site. When you set your IP info manually, you do NOT need a specific computer name!