A question on available speed from my modem

In my little town, AT&T DSL is one of the two choices for high speed internet. I use them because the cable company is both overpriced and unreliable over the long term.

I was having some issues in my available speed for nearly a week. AT&T sent out a technician and found the problem in their system…it wasn’t anything at my house or in my equipment.

The top speed that I’m supposed to get is 6mbps. After fixing the problem, the tech found that the modem was getting this speed consistently. But going through my router (wired connections only) to my computer, the speeds I get are well under that, in the 4.78 to 4.9 range most of the time on any speed test I try. The technician could not explain why.

Anyone have a clue? If it helps, the DSL modem is a Siemens Speedstream 4100 and the router is a Buffalo Air Station Turbo G. I haven’t messed with any of the settings, and I only run the built-in firewall in Win 7.

I had one of the Siemens pretty sure it was a 4100 .
I have AT&T but slowest speed up to 768k . It usually tests in the mid 600k .
That is as fast as the AT&T company says I can get from my location.
According to a tech I had out that found a bad switch in their system I’m really close enough to an AT&T box with fiber optics I should be able to get their top speed . So AT&T is lieing to me . I had to get that out.
I also have what is called a dry loop . That is one witout phone service on it.

When the Seimens failed I went with a Zoom & have been satisfied with it.
Zoom Telephonics X3 DSL 2/2+ Modem/Router/GW Model 5760 ADSL X3

Kerry I can’t remember is the Seimens just a modem or a router modem ?
The ZOOM is a router modem . This means I had to turn my router into a switch .
To avoid conflict . So you might check on that .
You need to do things like turn off the DHCP server in the router if you have a modem/Router . Don’t be fooled by only one ethernet jack on the modem. A modem/router is designed to be used with a switch if you use more than one computer on it.
I wanted to keep my router as a wireless acess point too.

Don’t think it is a modem/router cholla, just a modem.

The tech did say it was in bridge mode, which is necessary when using it with a router.

Hi Kerry , I didn’t have a router when I was using the Siemens . I think that bridge mode does sometimes slow the speed . I will see if I can find something on that.

The only things I can suggest unless there are some router settings for this router
are try a different ethernet cable between the router & modem or a different jack than # 1 on the router. Also try the router with just the one computer connected .

If you aren’t already doing this set your computer up with an internal static address . I haven’t used briged mode so I’m not sure about this but you may even be able to set the router with an external static IP address . Then let the modem work with the Dynamic IP address that AT&T uses unless you pay extra for a static IP address.

I also use one of the Google DNS servers & one AT&T DNS server. So far this is working fine.

I don’t know how you tested the Download speed but the best way is to download a large file to your computer . The speed test sites like to make results look good so you keep coming back .

Also : How many lights does your Siemens 4100 have ?
There should be some additional model numbers too . At least I think there are.

Just an hypothesis but maybe cables are the cause. Even if according to specifications 10/100 speed is fully supported by a cat 5 cable up to 100m length, maybe a too long cable (even if less than 100m) cause some sort of signal loss if the router is not able to provide enough energy.

To exclude the router as cause, however, I think that the easiest way is to try a different router. Can you ask a friend to borrow one just to run a quick test? :slight_smile:

In case you need more power, there are two possibilities: getting a more “powerful” router, or getting a PoE switch, to be placed between router and computers.

Do you have QoS enabled in the router? Did you try to disable and see if it improves performance?

Thanks for the ideas, but I think I’ll leave well enough alone.

The cables are about 8 ft and 10ft long, so I’m pretty sure they’re within spec. Using different ports on the router does nothing different.

And I don’t have access to another router. So that’s out.

It seems strange to me that a router can cause such a drop of performance.

The only cause that I can think is that QoS is not working correctly or is set wrongly. For example, my new router allow to manually set a specific value of bandwidth to the WAN and LAN ports, so setting a value lower than the bandwidth provided by ISP cause a reduction of speed. Did you check if also your router allow this?

No mention of QoS anywhere in the router interface.

I wonder if there is some sort of “benchmark” tool to check the actual router speed, something like tools used to measure HDD speed. Probably the speedtest is not accurate to measure the actual hardware capabilities

[QUOTE=geno888;2657796] my new router allow to manually set a specific value of bandwidth to the WAN and LAN ports, so setting a value lower than the bandwidth provided by ISP cause a reduction of speed. Did you check if also your router allow this?[/QUOTE]

I checked my router & I do have an upload bandwidth value that can be set if checked. On reading about this it is for networks with more than one computer so any one of the computers can’t use all the upload bandwidth . That is if more than one computer is on & using bandwidth . This is not my situation so I left it unchecked as it already was.
No setting for band width though.

I did go ahead & make some settings to turm the router I’m using as a switch with wireless access point to even more of just a switch.
Mostly disabling NAT by opening , DHCP , & UpnP basically anything that the router would check packets with or block anything.
These are all set enabled on the Modem/Router so this only gets done once.

Hi Kerry , I still think that the Siemens Speedstream 4100/4200 is a modem/router . Look at this manual & see if you agree.

As I posted above if it is you need to let it be the router & turn your router into a switch . If you don’t you are double processing the data in & out. I think this is the cause for the slow down .

This is AT&T speed test site I think you will find it showing an even faster speed that you have. It does for me.

I think you will find this site has more accurate speed tests as well as the ability to select the test size if you want too.

Interesting that the Siemens has that capability. Its been in bridge mode since I got it and went through the instructions from AT&T on how to set up the local network. And in bridge mode, you cannot access the controls. I’d rather not have to contact AT&T again to reset my connection if I drop out of bridge mode.

I am not convinced that bridge mode slows anything down, nor was the technician I was talking to about it.

The speed test site you linked shows the same type of speeds for my connection. 4.8mb on their test.

Just to let you know when the Siemens 4100B I had crashed I connected the Zoom above without even calling AT&T. I didn’t have a router when I had the 4100B or a wireless laptop like now. I did all that without any help from AT&T .

I did some reading on “bridging” & it said that you have to contact your IP provider for addresses to bridge . So I understand why you wouldn’t want to change it .

It seems that bridging lets data just go strait through the modem .
If I used bridging I still would have disabled anything that checks data like NAT & DHCP . Maybe the tech did when he helped you do the bridging .

A friend of mine had a Buffalo cable modem & he liked it so I understand how you might want to use it with its full router functions.
It may be that the router is doing a thorough job of checking data .
Since you know the modem by itself was able to get about full speed the bottleneck
has to be the modem or cables .
Just for curiosity you might do a "route print " from a command prompt .
On my set up this only shows the route to the modem & about the same as ipconfig /all .
I can check the modem & the actual incoming statisics by logging into the modem .

[QUOTE=Kerry56;2657872] The speed test site you linked shows the same type of speeds for my connection. 4.8mb on their test.[/QUOTE]

Interesting when I test AT&T’s test site shows my download speed as 3 times what it is . The upload speed is about the same on both sites .
The other test site is very close to what Windows downloader & another software I have shows when doing a large download .

IDK why.

One thing I like about both tests are neither is JAVA based.