US Cable Support > Comcast HSI > [Speed] Valid Comcast Speed Measurement?

[Speed] Valid Comcast Speed Measurement?

What type of router are you using?

reply to boleyd
DO NOT RUN THIS!!!!!
It is the Install Wizard for Comcast, but you really don't want to run it!

Just download it to see how fast it goes then delete it!

»pitt-cdn01.summitpark.pa.pitt.co···zard.exe

From Summit Park Pitt.
Should fly for you!
--
Think outside the Fox... Opera

reply to dr2500
RP614v3 is the Netgear router.I have tried various settings of the Receive Window value but most of the Broadband sites remain at 2400kbs or less. NY and Forth Worth are exceptions with 3.3 to 4.5kbs speeds most of the time. Hops do not always have a bearing on the results thus the accumulated un-ACK'd packets might not be an issue.

If I had a place I could test my speed, that was acceptable to Comcast, we could have a meaningful discussion. I have not contacted them except for one email which assumed that I had one or more of 5 problems - sometimes called boilerplate.

I do not want to enter into a protracted process where I have to go through a hour long "religious" set of steps to get to what would be the inevitable - truck dispatch. A Comcast respected download test would be sufficient for me. In fact I suspect that I may not have any problem but am a victim, as we all are, of the vagaries of the Internet. One test and I go away.

Regards,
Dick

Have you bypassed the router?

That router tops out at 7 megs with the firewall turned off. Looks like 2002 router.
»smallnetbuilder.com/component/op···art,119/
Look all the way down almost at the bottom

reply to axelrose
It depends on what tier you are on. If you are on the 8meg tier without powerboost then that is excellent, and technically a little over the rated speed which leads me to believe you did have powerboost kick in and it just throttled back down by the end. The 8meg tier is essentially 1MB/sec which is equal to 1024KB/sec to 1100KB/sec is a little faster than normal. If you are on the 6meg tier, you should see roughly 768KB/sec (without factoring in powerboost.

boleyd , the only downside to this test is that it only tests Comcast's network. Public speed tests are affected by the internet backbone and as such one congested link or overloaded server/router can bring the entire thing down to a crawl. This is why Comcast doesn't "officially" consider public speed tests, there are just too many variables that are outside of their (and your) control.

Now if you have slow speeds with this test then yeah Comcast has a problem on their hands and you have a legitimate complaint. Consistent slow speeds on public test server could indicate a problem but not one with your connection, especially if you get good speeds on the internal Comcast network. Slow public speed tests (and slow downloads) indicate problems outside of your control (and possibly outside of Comcast's control). These problems (just like before) could be an overloaded server (or not enough bandwidth at the server), overloaded backbone link/router or congested peering point.

reply to axelrose
1100KB/sec ~ 8.5mbps

From Tenn to Pitt... that aint bad!

reply to mdmaddox
I downloaded the file and it was shown at 280 kilobytes per second under Windows XP. This is roughly 2.2megabits per second. I have connected the PC (2GHZ)to the modem with no obvious change in performance. However, as noted the Internet is far from a stable environment and once you are beyond one hop more and more doubt creeps in. I need to use the Comcast file direct to the modem next.

I am now confused by the tier descriptions. I had seen this in other messages and was going to ask about it anyhow. First, I believe I am on a 6 megabit per second tier download. If I look at the example on the 8 megabit per second it says that "The 8meg tier is essentially 1MB/sec". This is where I become confused. What is the relationship between 8 megabits/sec and the 1 megabits/sec? Which value is seen in the speed tests?

Thanks & regards,
Dick

Their relationship is pretty easy to understand. 8Mb/sec is the same as 1MB/sec. Notice the difference in the B, B = Bytes, b = Bits. There are 8 Bits to a Byte. Thus, 8 Megabits/sec equals 1 MegaByte/sec.

If you wanted to calculate that, you need to transition megabits into bits for easier computation. In this case 8Mb is 8192 bytes (8 * 1024). 6Mb is 6144 (6 * 1024). There are 1024 bits in a megabit. Now that you have the number in bits you can convert that to bytes by dividing by 8 (remember the 8 bits in a byte). Thus, 8192 bits is equal to 1024 bytes and 6144 bits is equal to 768 bytes.

All you really need to be concerned with is that 8 Megabits/sec means 1 MegaByte/sec and 6 Megabits/sec means 768 KiloBytes/sec (or 0.786 MegaBytes/sec). Given you got 280KB/sec off of the Comcast install file I would say your issue definitely lies with Comcast. Comcast's network consists of 10 Gigabit/sec links between virtually everything with the exception of the link between the core routers and the CMTS which is 1 Gigabit/sec. It would take a LOT of traffic to saturate that kind of a link. Most systems are now interconnected via the same 10Gb links so you should never hit the public internet even when talking to a Comcast server in another state. Now, I can't say what the cause of your issue is given the information at hand.

Joel

reply to boleyd
If you don't know how to check your signal level in your modem check this FAQ out.
»Cable Modems and Wiring Issues

Please post.

reply to JoelC707
So the iussue is with the "B" word (byte or bit). When I managed a larger corporation's comms net the rule was to always use bits per second when referring to communications transfer rates. Bytes were used to denote storage and memory factors. I guess that there has been some drift from that convention. So the elderly are confused.

I have not seen any PowerBoost propaganda here so I believe that we are pure vanilla in that regard. Since I do get 4.5mbits/s at times I can suspect some net router, or my modem, or my drop line is faulty. From my past experiences a suspect would be a router config. I will check the modem signal level. My scope only goes to 20mhz so it is not the instrument of choice. The software snmp process is involved so that will take time.
EDIT- Comcast appears to have blocked the SNMP for my Surfboard 3100 modem. Looks like I will have to endure the resets and param checks of "customer service". Then await truck dispatch. My HDTV does occasionally have some pixels but not bad enough to make the dreaded call. Time to fix everything.

Regards,
Dick

reply to dadkins

reply to boleyd
From Comcast FAQ
SB3100D Can't find your manual? View it on Comcast.net! (requires Adobe Reader)

This modem cannot be upgraded to comply with the DOCSIS 1.1 specification. If you currently use this model it is not necessary to remove it from the network. However, this device should not be returned to service if sent back to the warehouse, nor should it be purchased for use with the Comcast High-Speed Internet Service.

reply to boleyd
If you're still using the 3100 then I think you're due for an upgrade. That model is ancient...

Thanks for the FYI on the 3100....

reply to boleyd
I downloaded that file just now and I'm only getting 130KB/s tops. I had techs here less than half an hour ago and they said that I'm fine even though every public speed test out there I hit tops out at about 3000 kbps. Was told that when those commercials say 6000 kbps they only mean "up to" 6000 kbps.

Really missing my DSL.

What file?