Comcast CAP (What is it)

Lobo · Post by **Lobo** » Tue Jan 08, 2002 4:32 pm

1.5

Write your congressman, senator, (READ MY LIPS JR.)
This must be raised

HalfLifer · Post by **HalfLifer** » Tue Jan 08, 2002 5:56 pm

Um, its 1.5mbps/128kbps.

I heard that they will have tiered service. You pay for more bandwidth.

jarablue · Post by **jarablue** » Tue Jan 08, 2002 8:40 pm

Get used to it. That was la la land you were living in before. You have to pay for more. That is how it works in the real world. I can't believe you are complaining because 1.5 is slow???? Geez dude you need a reality check.

HenryHand1 · Post by **HenryHand1** » Tue Jan 08, 2002 11:54 pm

1.5 is slow compared to what users of many other cable ISPs get. Those caps almost make it a better idea to get DSL.

Take Optimum Online for example; I've seen people get as much as 8MB/second and over with that service. w0w.

That's probably not a good example, but how can comcast justify raising the price by $5 per month and lowering the speeds so much?

EvilAjax · Post by **EvilAjax** » Wed Jan 09, 2002 12:13 am

I'm satisfied with my DSL speeds.

** Speed 1510(down)/115(up) kbps **
(At least 30 times faster than a 56k modem)
Finish.
Capped at 1.5mbps down and 128kbps up.

latin · Post by **latin** » Wed Jan 09, 2002 12:33 am

guys im Capped at 1.5mbps down and 128kbps up how can i ge the most out of it I have attbi right now my rwin is 64240 why?
because of this thread i found check-->Ok this one is a refinement on something I already posted but deals with a specific area. The specific area is the NIC card and what it sees as the actual TCP Window size.

yes, yes, I know "But I already did the TCPWindowSize thing in the registry and its screaming along" (or not). But did you ever stop to think what the actual window size your using really is? I know all about speedguide and their tcp window size tester thing and how they say your all good and stuff, and about the almost exact opposite advice from dslreports. Guess what, they are both right. Yep, thats correct, both right.

Ever notice how when you first install XP the connection seems to just be "smoother" with browsing, may not be getting 10MB's on the speed but it is nice and smooth, you'll at least get 2 MB/s on the cable modem. This is because the window size its using when forst installed is 65536 which is the optimum size for MS/s TCP/IP. So what you have less flow controll from the NIC and less interaction for flow control from XP because it really happy with this size window.

Ok, your connected to the cable modem with a NIC card. So whats the true window size your using? "Huh, my registry says 256960 (or something), so thats what i'm using". Nope, wrong, thats what your trying to use, what your actually using is what the NIC card sees. TCP is doing the rest, but what your physically using is what the NIC can see and this is what it sees. To demonstrate click on this link:

hcp://system/netdiag/dglogs.htm

or if clicking on it doesn't work create a shortcut with this as the path, just as it says, dont change it. this will open up the winXP built in network diagnostics. When it opens click on the "scan your system" link and let it do its thing. When it gets done, scroll down to where it says network adapters and expand the branch. then sroll down under this branch and look for the TcpWindowSize entry. see the number? it may be in the 40xxx area somewhere. If the number you see begins with 60 then skip this whole post as you don't need it. This is what the NIC is actually using for a window size. Dissapointed? yep...sure you are.

the real trick to setting a correct TcpWindowSize in the registry is to get the unscalled window size as close to 65536 as possible. But after you subtract all the overhead you wind up with less than that sometimes. Well guess what. the max window size the NIC is going to possibly see is 65536 less the TCP/IP overhead and the NIC card overhead and the NIC drivers overhead. You can't control these things (well the TCP/IP overhead a little).

write down that number you saw in the diagnostics and keep tabs on it, were going to change it. keep in mind that i'm using 3Com 905B-TX cards and have only tested with those cards.

Open up our old friend regedit again.

browse to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters

add these reg keys - as DWORD

"DefaultReceiveWindow"
"DefaultSendWindow"

now modify each one with the value of the large window size you have at the reg location:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

make "DefaultReceiveWindow" and "DefaultSendWindow" the same size as TcpWindowSize for starters.

now reboot

run the diagnostics again. Remember the first number that you wrote down? compare it to the new number. If you didn't see a change then change the value (double it) of the "DefaultReceiveWindow" and "DefaultSendWindow" entries - reboot and try again.

Eventually your going to get to the number 60352 or there abouts. This will be the largest possible unscaled window that your NIC will see that is less than 65536 (ref the MS knowledge base).

adjust the "DefaultReceiveWindow" and "DefaultSendWindow" entries till you get the number as large as possible. When you get the number as large as possible then its time to fine tune a bit. Decrease the number by 10% and check again, repeat this till a change is noticed that the number is dropping. When the number begins to drop it means that this is the optimum value for your "DefaultReceiveWindow" and "DefaultSendWindow" entries and no more can be gained by changing these entries.

LOBO EXPLAIN PLEASE IM GOING CRAZY TRYING TO FIGURED THIS OUT!!!!!!!!!!!!!!!!!!!!!!1

Kip Patterson · Post by **Kip Patterson** » Wed Jan 09, 2002 7:13 am

Sorry, but the NIC has nothng to do with Rwin. The NIC only deals with layer 1, Rwin is part of the TCP/IP protocol on layer 3.

Kip

Lobo · Post by **Lobo** » Wed Jan 09, 2002 9:02 am

I use (with XP) 578160 and get all I can out of my 1.5 CAP

YARDofSTUF · Post by **YARDofSTUF** » Wed Jan 09, 2002 12:06 pm

Originally posted by jarablue
Get used to it. That was la la land you were living in before. You have to pay for more. That is how it works in the real world. I can't believe you are complaining because 1.5 is slow???? Geez dude you need a reality check.

i was payign 50 a month for 10mbits down and 128kbps up and now i pay 50 for 1.5 down 128 up, so i took a 85% cut in download speed.

if u stopped getting 85% of ur cable channels or 85%less of a magazine u subsribe to, would u be pissed?

they should lower the price or raise the speed!!!

so yes i willwine and i am in the real world

akaduke · Post by **akaduke** » Wed Jan 09, 2002 12:15 pm

well i have attbi at home and my average speed is 1.9mb and sometimes it even goes up to 2.2mb.. but im still trying to make it go up to 4.0mb..

YARDofSTUF · Post by **YARDofSTUF** » Wed Jan 09, 2002 12:48 pm

Originally posted by akaduke
well i have attbi at home and my average speed is 1.9mb and sometimes it even goes up to 2.2mb.. but im still trying to make it go up to 4.0mb..

attbi is capped at 1.5 thats what i have, what are u using to test this?

akaduke · Post by **akaduke** » Wed Jan 09, 2002 1:06 pm

hmm.. it's one from microsoft page.. but ill post the site later when i get home..

akaduke · Post by **akaduke** » Wed Jan 09, 2002 1:19 pm

oh i found it.. here:

http://tech.msn.com/internet/speedtest.asp

here what i got form speakeasy.net:

**speed 2184(down)/61(up) kpbs**
(At least 43 times faster than 56k modem)
Finish

and here's i got from http://tech.msn.com/internet/speedtest.asp

1651.8 Kbps 1651.8 kbps

Lobo · Post by **Lobo** » Wed Jan 09, 2002 8:21 pm

Speakeasy test is cool, but others are El Crapo

latin · Post by **latin** » Thu Jan 10, 2002 3:49 am

this is what i got
** Speed 1437(down)/110(up) kbps **
(At least 28 times faster than a 56k modem)

IS THIS GOOD?can i inprove upload a lil?

Lobo · Post by **Lobo** » Thu Jan 10, 2002 8:04 am

Try putting a large number like 578160 in Default Send Window

illestdynasty · Post by **illestdynasty** » Thu Jan 10, 2002 6:23 pm

if its 1.5Mb how come i stay around 2.5+MBs????

Lobo · Post by **Lobo** » Fri Jan 11, 2002 1:12 am

Because they have not switched you yet, hold on

mixmaster456 · Post by **mixmaster456** » Fri Jan 11, 2002 7:51 am

I have Charter Pipeline and I am capped at 786 down 128 up or 14 times 56k I was getting 106 times 56k with @home, is there any possibility they will increase the cap with time? I was switched over on January 9th. Its upsetting, not only are my speeds terrible but they raised the price! It's amazing.

Lobo · Post by **Lobo** » Fri Jan 11, 2002 9:16 am

Same to me, raised price 5 dollars from 109 times fater to 23, man I have tried everything, guess I'll join Delta Force