If you are a new Comcast customer running Windows 2000 and have
used their software to activate your cable modem, beware that this
software is a piece of ****.

I had my computer on RCN cable modem before we moved to a location
serviced by Comcast. The computer had no problem with internet
browsing, so I was a bit disappointed when after moving to Comcast
some sites would not load at all and some would take the incredible
amount of time to come up.

Furthermore, the computer had Win2000 SP3 installed at that time and
when SP4 came out I tried to install it and Internet died all together
( luckily I chose to backup the system state before install and was
able to roll it back to SP3).

What added to frustration was that 'ping' and 'tracert' always worked
OK.

After doing some extensive investigation I discovered that 2 values
under
"HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servi ces\Tcpip\Parameters"
registry key were erroneously given REG_SZ type instead of REG_DWORD.
The values are 'GlobalMaxTcpWindowSize' and 'TcpWindowSize'. The use
of these values is controlled by the 3rd value named 'Tcp1323Opts'
which was REG_DWORD=3.

Because I did not tamper with the registry settings before ( I did not
know about their existence until this morning ) and computer worked
fine before it joined Comcast network, I conclude that it is their
installation program that wrote bogus values.

Resetting Tcp1323Opts to 0 immediately returned normal speed to
internet browsing.

After that I was able to tune the settings using recommendations from
"http://www.auldfart.co.uk/broadbandtweaks.html".

Note that you need to reboot your machine in order for the registry
changes to take effect.

After that I was able to install SP4 without any problems.

As of Comcast tech support ... My experience with them added newest
anecdote to my collection. After calling and complaining that
internet browsing had crawled to a halt when I installed Windows 2000
Service Pack 4, the guy on the phone asked me "What is 'service
pack'?".

Hope this posting might save you countless hours of frustration.

-Alex

NEVER install software obtained from any ISP, no matter how you connect to
the Internet. This is especially important if you are an AOL user. That
is, if you sign up with AOL, don't install the AOL software. -Dave

Alex wrote:

The values available for this key are:
0 = disable RFC 1323 options
1 = window scale enabled only
2 = time stamps enabled only
3 = both options enabled

Take a look at:
http://www.pcmag.com/article2/0,4149,1170893,00.asp

TcpWindowSize Registry setting. Some, however, are shackled with
exorbitantly latent networks, and adjusting the receive window alone is
not satisfactory. Fortunately, the IETF has published RFCs 1323 and
2018, which enable TCP windows greater than 64K and permit machines to
acknowledge lost packets selectively rather than retransmit the entire
receive window. When both sides support these RFCs, you can realize a
significant performance boost by using large windows.
<<<

Essentially, you've turned off these features. In some cases this would
have caused more speed problems, and at best, make no difference. Why
you would have seen an improvement in speed by disabling window scaling
doesn't make sense. Even the page you cite:
http://www.auldfart.co.uk/broadbandtweaks.html
says:

loss, however generally you'll achieve better throughput with
Tcp1323Opts="1", since Timestamps add 12 bytes to the header of each
packet.
<<<

Essentially, what you should theoretically loose by disabling this is
not going to be made up by loosing the 12 byte header. In other words, a
value of 1 is probably the best, but it's not going to be significantly
different than a setting of 3, even if the servers do not support
timestamps. But a value of 0 or 2 ought to be significantly slower than
either 1 or 3.

--
Warren H.

==========
Disclaimer: My views reflect those of myself, and not my
employer, my friends, nor (as she often tells me) my wife.
Any resemblance to the views of anybody living or dead is
coincidental. No animals were hurt in the writing of this
response -- unless you count my dog who desperately wants
to go outside now.
Blatant Plug: Spend your Amazon gift certificates here:
http://www.holzemville.com/mall/associateshop.html




--
Warren H.

==========
Disclaimer: My views reflect those of myself, and not my
employer, my friends, nor (as she often tells me) my wife.
Any resemblance to the views of anybody living or dead is
coincidental. No animals were hurt in the writing of this
response -- unless you count my dog who desperately wants
to go outside now.
Blatant Plug: Spend your Amazon gift certificates here:
http://www.holzemville.com/mall/associateshop.html

Warren wrote:
Thanks, Warren; it's a keeper.

Q