Extreame Comcast speed, how is this possible?

[Starstreams]

This is really strange. How is this possible?

A few days ago I updated to Comcast Blast, and picked up a Motorola SB6120 Doc SIS 3.0 modem. The upload speeds are sometimes 2, or 2.2Mbps. No complaints, it's better than the 130Kb/s cap I had before. Anyway, I started testing CrashPlan backup site, which has no speed restrictions. When the blast kicks in, I'm getting upload speeds as high as 400+ Mbps. In this case, 411.6Mbps Wow. that's 51.4MB/s upload. Then after a few mins, my connection throttles back down to it's normal sustained rate of 2 or 2.1Mbps.

See attached Screenshot
http://postimage.org/image/1l3mp3abo/

What I don't understand is, My Netgear router is rated at 100Mbps, so how can I be getting these speeds? This is the router.
http://www.netgear.com/business/products/security/wired-VPN-firewalls/FVS318.aspx

I've sent this screenshot to Crashplan support to see if there is something wrong with the readout of their software. There is no way these numbers are correct. I think even the most expensive Comcast business plan is only 10Mbps for Uploads.

[Bryan]

Most likely there using a speed boost technology which gives a temporary bump in download rate for a short period of time.

[/\/\adGamer]

I would say its a flawed speedtest

[Bryan]

Interesting, that sounds more like compression being used and being stated as actual transfer rate which is rather deceptive.

[/\/\adGamer]

I dont trust too many speed tests

[Ryokurin]

The SB6120, can do 4 channels of bonding due to docsis 3, and as a result the powerboost capabilities can be a lot higher than what they quote it should be, depending on if a lot of people are using those channels for data where you live. For instance, when I went to a docsis 3 modem, I went from a powerboost high of 20 megs to 30, even though the plan I have should be fine with a docsis 2 device.

[Bryan]

Powerboost is download, the OP is referring to upload of 400 Mbps. ( Misread how the post was stated originally.)

OP's upload is 2 Mbps, and the 3rd party service is indicating a 400 Mbps upload rate.

This could be including live compression on the utilities end which is deceptive but could account for the extremely high upload.

[/\/\adGamer]

docsis3.0 devices only use the 4 channels if the boot file in the modem and outlet codes at the head end on that particular account are set up in sync for 3.0 speeds if not they are docsis 2 backwards compatible the speed test in this case is jacked!

[Bryan]

Which doesn't matter when the router is capped at 100 Mbps.

[Starstreams]

Hi, Thanks everyone.

I got a response back from the CrashPlan team, they said...

...what you are seeing is an initial "synch" of your data.
This is when you restart your computer and CrashPlan goes through your files to find where it left off so it can back up any changes.

I guess what made me ask the question is, First I would see the message analyzing, but then it would change to transferring, and held for about 2 mins with it transferring at 400+. The message labeling is not timed well with whats really happening I guess.

Speaking of speed, it's not as good as I thought. I've upgraded to Comcast Blast. They advertize that I should be getting around 3Mbps upload, and I'm only getting a sustained rate of 2Mbps, or 250KB/s. My download speed is no better then it was. This is even after I picked up the recommended Motorola SB6120 modem. I've had two different line techs out in the last three weeks, and both said that there is something wrong with the upstream signal, and that they needed to fix the entire block. Now I get a message on my answering machine saying that they fixed the problem and all service requests have been canceled.

Now I've just upgraded to the basic business plan because I'm tired of their residential support. I'm hopping I'll get better speeds with the dedicated line. They can't seem to give me the speed I'm paying for. I am so upset with Comcast lately, and their lack of coordination and communication. Sorry to vent, I've had a bad two weeks with them, every day on the phone. They don't deserve what they charge.

[Bryan]

Yeah, the ISP out my way is doing a series of infrastructure upgrades out my way which is messing with my connection.

Sometimes you need them to send out a tech to check from your end, hopefully the business grade connection is better.

[Starstreams]

Yeah, the ISP out my way is doing a series of infrastructure upgrades out my way which is messing with my connection.

Sometimes you need them to send out a tech to check from your end, hopefully the business grade connection is better.

Hi Bryan
I got lucky when the 3rd Comcast line tech came out after I upgraded to the business class. The first two guys didn't find anything. The last guy told me there was a ton of noise on the line in the house. He found a bad coupler on a splitter in the crawl space just from turning it a 1/4 inch, and instantly his meter showed a clean signal. He also looked at the wall jacks that I had hooked up two years ago. Although they were hooked up correct color wise, I didn't have the twist close enough to the punch point, which I guess is critical as the twist is what cancels out line noise. It was a good lesson. I should also note that I used Cat5 (Not Cat5e) braided patch cable in the walls. So it's time for an update.

anyway, according to Speedtest.com, (which I have little faith in it's accuracy), it's saying my downloads/Up with the business plan is showing 25 to 34Mbps down/ and 4.2, sometimes 2.6Mbps up. But so far the fastest I've been able to upload as far as real world speed is 280Kb/s, to 300KB/s and downloads are sometimes over 1MB/s, but usually around 500 to 800KB/s. I should have used solid Cat5 when I did it. I'm going with Cat6 solid now.

[Bryan]

Speedtest.com measures the full pipe from your premise, through your provider and up to there hosted servers. ( Basically telling you what the capacity is)

However, every site has a different route, different traffic policy and different traffic which all effect your speed. Needs to be remembered that broadband isn't just about speed but the ability to handle multiple connections. ( Think family/group capacity rather then individual.)