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Cable Modem Speed drops to 2mbps at all nodes

By echous ·
Comcast cable modem connected to Linksys Wireless G, 2.4 GHz, 4 port, Broadband Router. Router connected to Windosws 2003 server, 3 desktops and 1 laptop. No matter which port in the router the server is plugged into it, CNET Bandwidth test shows 5 mbps. All the other pc's see 2 mbps. What's causing the slowdown to the nodes?

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Questions and Comments

by TechExec2 In reply to Cable Modem Speed drops t ...

Q1. How are the 3 desktops and the 1 laptop connected to the LAN? Wireless B? Wireless G? Cat 5? 100 Mbps? 10 Mbps?

Q2. What operating system are the 3 desktops and 1 laptop running?

Q3. How fast are the CPUs in the server, 3 desktops, and 1 laptop?


It sounds like at least 1 of your PCs is connected via Wireless (only 4 hardwired ports on your router). Any node connected via Wireless G has a theoretical maximum of 54 Mbps but will get less at all times. If Wireless B, only 11 Mbps but will get less at all times. If it has a weak signal, even lower still.

Any other traffic on your wireless, or wired, LAN will adversely affect the test.

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by echous In reply to Questions and Comments

A1: 3 desktops connected via Cat5 @ 100 mbps. 1 laptop via Wireless B (11 mbps, 20ft from router)

A2: 3 desktops running 2000 Professional and laptop running XP Home

A3: 2003 Server is 2.4 ghz, nodes are 933, 750, 732 mhz. Laptop is 1.6 ghz.

Also, switched ports to see if 5 mbps stays with port. No it stayed with 2003 Server. Switched Cat5 cable to see if higher speed stayed with cable. No, it again stayed with 2003 Server.

Finally, event viewer showed following...

Event I 7000
Event Source: Service Control Manager
The Network Load Balancing service failed to start due to the following error: The service cannot be started, either because it is disabled or because it has no enabled devices associated with it. Network Load Balancing is not installed on the system.

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CNET bandwidth test measures more than bandwidth

by TechExec2 In reply to Update

I ran some tests of my own and got similarly varied results. It appears that CNET's test is GREATLY affected by CPU speed, and also by browser. IE was 12% faster than FF.

So, it is a misnomer for them to call it a "bandwidth test". It is a measure of throughput using your network, computer hardware, AND your browser software, not just bandwidth.


All of these system are connected to the same LAN router via CAT-5 at 100 Mbps:

FF 1.5: 2463, 2374, 2331 Kbps
IE 6: 26**, 2693, 2664 Kbps

SYSTEM 2: FEDORA CORE 3 LINUX, AMD Athlon 64 3000+
FF 1.5: 26**, 2696, 2695 Kbps

FF 1.5: 879, 892, 870 Kbps

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Re: Test Results

by echous In reply to CNET bandwidth test measu ...

I don't know where to go from here. Is there a better test site? Is anything broken? Even at "2 mbps", IE performance isn't typically a problem, although the "5 mbps" server surfing response is definately nice.

Next step for me is to Cat5 the laptop to see how it's higher speed responds to a 100 mbps network vs the 11 mbps wireless.

Thanks for help.

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My test results...

by TechExec2 In reply to Re: Test Results

My test results, and yours, showed that there is a strong correlation between CPU speed and the CNET Bandwidth Speed Test. That is, CPU speed really matters when it comes to getting the most speed out of web browsing on a high-speed Internet connection.

So, you must upgrade your four slower systems (3 desktops, laptop) to higher speed (go for around 3.0 GHz...good price point) in order to get the most out of your 5.0 Mbps cable modem with them.

Even if you don't upgrade them, 2 Mbps is pretty darn good. Just a short few years ago, "high speed Internet" by cable modem was 300 Kbps (0.300 Mbps) and most people had 28.8 Kbps modems (0.028 Mbps).

Whine whine whine!!!

You're doing very well. Take care.



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Your not seeing the whole picture

by bcriswell3400 In reply to Cable Modem Speed drops t ...

It's not the speed at the node that messures how much speed your getting. If your only getting 2 mbps at the nod then there is either a problem with that node. The reason is probably that somewhere in your home you have ingress or degress probally both. If any Tv, VCR, etc is hooked up in your comcast system and your using say one of those push on cables or a cable from radio shack or a spilter that didn't come from comcast, that's where your losing your bandwith. It's going into thin air, being broadcast over the airwaves. Check all your coaxial cables and splitter and make sure there from comcast. If you have a radio shack splitter and yes even the "gold plated ones" they are junk. They don't have the proper wiring and shielding in them that are needed to get the speeds you supposed to get out of your modem. Also any none comcast coaxial cable is more than likely not triple shielded with a copper clad center conductor. That's right your losing signal out of your cables themselves. If you check all your cables and splitters and there not comcast have them come out and replace them. If you have all comcast cable's and splitters there is also a very good chance that the neiborhood squial has chewed into the drop coming from the node or from the feeder down the street somewhere. Or one more possiblity is that your service was hooked up in what's called a looped install, which is where you loose alot of signal as you go through each wire. If it's not hooked up in a homerun config then you won't get the speed your supposed to. I do this for a living, so trust me it's a 99%chance that there is nothing wrong with the node unless they didn't terminate all the node drops that are not hooked up to a house. Call them out and explain when you call that your speed tests are way below values they should be. They'll come out and find the problem and fix it. There are so many different variables that can cause signal loose that's it is just not the correct thing to say the speed is slow at the node. With that said. All high speed service is checked daliy. Your modem sends a signal to the head-end of the cable plant or to the HSI center in Michigan and they know in one second if there is a problem with anything from the plant to the node. Now if a comtech hasn't come out, then I would bet the bank you have a cable in your house that is not shielded properly and your loosing all that speed into thin air. Look at the very first cable that comes into your home from the ground block. Every cable connected to anything in your home should look just like it, same numbers on the cable and the rf connectors should all be the same. Also the spitters should say regal on them, that's the comcast standard spitter that works very well. If you do have something that doesn't match the rest of the stuff get rid of it. Call comcast and get a new cable, or splitter. But don't go buy one yourself. Sure you can get a cable that will work out there, if you know what your looking for but do you have the correct RF commpression fittings and the tools to install them right? I promise if you look at everything I've told you, you will find that bad spot in your cable that is sucking the life out of it. I hope this helps. Sorry about the spelling, I'm very tired.

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Incorrect -- The problem is not the coaxial cable or splitter

by TechExec2 In reply to Your not seeing the whole ...

One computer on his LAN gets 5 Mbps. The others are only getting 2 Mbps.

Read the entire thread and you'll see what is really going on here.

Merry Christmas to you...

P.S. Good information about coaxial cable and splitters. It just doesn't apply to this guy's case.

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was going to reply to that yesterday, but time was thin

by jdclyde In reply to Incorrect -- The problem ...

it is good information for anyone that is adding more outlets for their TV's, but you are correct that this has no bearing on this case.

Once it is handed off the the access point, the question is where do the PC's get their DNS from? Do they all get it from the internet provider, or from the server? If they have to poll the server and THEN go out, that is a possible hit.

Are they on-board NIC's in the PC's? Again, a performance hit.

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Did you find a solution?

by jtumin In reply to Cable Modem Speed drops t ...

Hi, I have a similar problem, so I'm wondering if you solved yours. I have a Comcast-supplied Arris modem (includes digital telephone service), connected to a Linksys wired BFRS41 router. P2P downloads show constant loss of signal between the 2, which resumes, but makes it very difficult (slow) to go from one webpage to another. I have 3 other computers hooked into the router; webpage transitions are horribly slow. They are only quick if I turn my computer off, then on, and it's only quick for a few minutes, then slows to a crawl. Do you have any suggestions? (turning the power on and off for the router only helps for a few minutes, too.) thanks.

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