[Severed Hand of Skywalker]

I noticed through other peoples screenshots that you can set the packet size for TCP packets. Rumor has it that the default for OSX is for dial up and setting it higher will increase speed.

If you don't have OSX 10.3 like me you can also accomplish the same thing by using cocktail:
http://www2.dicom.se/cocktail/index.html

If I am on a 3 Meg DSL modem that has 300k sec down and 90k sec up what would be the best setting for my up and down packets?

Is it the higher the better?

Also 10.3 seems to word it differently something in the area of "1500" is the default.

Any ideas?

[JB72]

Your best bet might be to head over to BroadbandReports and see what they can do for you.

I do wish there was some kind of general "formula" for finding the best settings.

[Camelot]

Originally posted by Severed Hand of Skywalker:
[snip]Also 10.3 seems to word it differently something in the area of "1500" is the default.

I think you're getting confused with MTU (maximum transmission unit) and the receive/transmit windows (which is what that dialog is tuning).

These are just two of the many, many tunable parameters available for optimizing network performance.

[cybergoober]

Using a tip from the April 2002 issue of MacAddict I edited the /etc/rc file as such-

End of file before editing:

Code:
SystemStarter -gr ${VerboseFlag} ${SafeBoot}

exit 0

End of file After editing:

Code:
SystemStarter -gr ${VerboseFlag} ${SafeBoot}

sysctl -w net.inet.tcp.recvspace=65536
sysctl -w net.inet.tcp.sendspace=65536
sysctl -w net.inet.tcp.delayed_ack=0

exit 0

I went to dslreports' speed test section before and after applying this "hack". I restarted the machine after editing the file, obviously.

The Results-

Before:

Code:
2003-06-27 18:45:30 EST: 3390 / 3169
Your download speed : 3390408 bps. or 3390 kbps.
A 413.8 KB/sec transfer rate.
Your upload speed : 3169572 bps, or 3169 kbps.
Seems like broadband .. above 1mbit barrier!
then a graph showing how it compared to averages of connection types

After:

Code:
2003-06-27 18:48:24 EST 6498 / 4207
Your download speed : 6498693 bps. or 6498 kbps.
A 793.2 KB/sec transfer rate.
Your upload speed : 4207573 bps, or 4207 kbps.
Seems like broadband .. above 1mbit barrier!
then the same graph, with different results ;)

So after the hack I nearly doubled my download rate. Then again I'm on a nice gov't network with plenty of bandwidth to spare.

[ambush]

I got dsl

max: 110 ks down
16 ks up

help

note that at my other house, [with the same ISP] I can download at 140 k/s. Maybe it the router, or the fact that I'm closer to the ISP.

[Severed Hand of Skywalker]

Hmmm, you guys seemed stumped!?

[Racfore]

Originally posted by Severed Hand of Skywalker:
Hmmm, you guys seemed stumped!?

The place to go is Broadbandreports.com Tweaks forum. I've spent a lot of time there already, so I can save you some work. It's generally agreed that setting the receive window (rwin) is the only tweak that makes a significant difference. Maybe also turning off time stamps (for Macs).

Read the first two sticky threads on this page:

http://www.dslreports.com/forum/news,61

Then check out the RWIN and Macintosh sections of this FAQ page. Use the formula to set your RWIN appropriately ... jacking it up to 65K like these tweaking scripts do can often cause problems and increase latency.

FAQ page:

http://www.dslreports.com/faq/tweaks/all

After tweaking my cablem connnection, I'm getting 3,000 - 3200 kbps on the speed tests. This is a 3,000 kbps / 128k capped system. It's maxed out, in other words.

Edit: You'll also want to pay attention to the PPPoE sections to make sure your MTU is set right.