TCP and WAN issue

Robert Boyle robert at
Tue Mar 27 21:04:20 UTC 2007

At 04:26 PM 3/27/2007, Philip Lavine wrote:
>I have an east coast and west coast data center connected with a 
>DS3. I am running into issues with streaming data via TCP and was 
>wondering besides hardware acceleration, is there any options at 
>increasing throughput and maximizing the bandwidth? How can I 
>overcome the TCP stack limitations inherent in Windows (registry 
>tweaks seem to not functions too well)?

You will have problems obtaining anything more than 5-7Mbit/s based 
on 1500 byte Ethernet packets and a RTT latency of 70-90ms. You can 
increase your window size or use Jumbo Ethernet frames. Almost all 
GigE gear supports jumbo frames. I'm not sure of your application, 
but without OS tweaks, each stream is limited to 5-7Mbit/s. You can 
open multiple streams between the same two hosts or you can use 
multiple hosts to transfer your data. You can utilize the entire DS3, 
but not without OS TCP stack tweaks or a move to jumbo frames. You 
can also use UDP or another connectionless packet method to move the 
data between sites. Good luck.


Tellurian Networks - Global Hosting Solutions Since 1995 | 888-TELLURIAN | 973-300-9211
"Well done is better than well said." - Benjamin Franklin

More information about the NANOG mailing list