new internet: 2 questions

[wtfbbq]

I recently signed up for Comcast. I'm using my old Motorola SB4200 modem from several years ago when I was with Cox. I'm signed up for the 8/2 mbps plan (with powerboost... so they advertise it as 16/2)

On actual speed tests it caps at 8.5 / 1.5 during the day (low traffic hours I'm assuming - I'm in a college town + live near campus), and 4.2 / 1.3 during the day. So I had 2 questions

- Is it normal to be this low below advertised speeds? Could it be related to the modem (it's rated at speeds of something around 35 / 15 or something... but it's also only DOCSIS 1.1, which I don't know entirely what it means except that the modem is no longer officially supported by Comcast)
- Would I be able to use QoS on Tomato with these varying speeds? I all I want to do is set bittorrent to be rated "lowest" behind all other traffic. But with these varying speeds, what would I set up the maximum inbound to?

thanks!

 

[somethingsketchy]

Well...there are several factors...it could be part of your modem, although that is highly doubtful since it would work with little problems. The only factor is the fact that Cable is a shared resource. If there are multiple people using the same cable line (from the same power pole for example), then the advertised speed of 8/2 could be a rare one. It all depends on how many people share the same line with you and other things (signal strength, noise, etc).

As for QoS, I believe you can set the numbers up as percentages instead of whole numbers, so if you have a really bad day where you can't even get 2.0Mbps, your QoS settings will still work, albeit slower.

For example if you have your torrent client set for maybe 15% of your upload/download speed, then whatever speed you happen to have that day, only 15% will be allocated for torrenting (instead of something like 1.0Mbps down/ 0.5Mbps up).

Hope that helps.

EDIT: added extra bit for OP's second question.

 

[spidey07]

you're not going to get the better speeds with that old modem.

 

[Cooky]

Why don't you lease a modem from Comcast and test?
If you consistently have higher speed, it's the modem.
If you get the same result, return the modem.

 

[wtfbbq]

thanks for the input guys. two clarifying comments:

- the part of QoS I was concerned about is the part where you explicitly state max bandwidth in kbits/s - my question was if all I'm doing is setting BT below everything, does it matter if the entered max bandiwdth is different than what it is at that time?
- the cable modem does reach speeds of up to 10 at some times. if it goes back down to 4.5, then that's comcasts fault?

and great suggestion about testing a different modem - I'll definitely try that out (though hopefully I can find a friend with one instead of having to pay.)

 

[somethingsketchy]

Originally posted by: wtfbbq
thanks for the input guys. two clarifying comments:

- the part of QoS I was concerned about is the part where you explicitly state max bandwidth in kbits/s - my question was if all I'm doing is setting BT below everything, does it matter if the entered max bandiwdth is different than what it is at that time?

Yes and no. By specifying a specific value (such as 2Mbps) for example one day you may have 10.0Mbps and not notice a difference and then the next day have 4.1Mbps and you'll notice the slow down. By specifying a percentage (such as 10%) then your torrent client will only download at 10% of the available speed at the time.

- the cable modem does reach speeds of up to 10 at some times. if it goes back down to 4.5, then that's comcasts fault?

Possibly, but you won't get Comcast to "guarantee" your 10.0Mbps. I believe it's right in their Terms of Service that you can experience the slow downs as the Comcast network in your area gets congested.

In fact that's probably why you're experiencing 4.5Mbps consistently, instead of 10Mbps.