Marshall Eubanks wrote:
>
> You might want to look at this classic by Stanislav
Shalunov
>
> http://shlang
.com/writing/tcp-perf.html
The description on this website is very good.
Disclaimer: I'm a FreeBSD TCP/IP network stack kernel
hacker.
To quickly sum up the facts and to dispell some
misinformation:
- TCP is limited the delay bandwidth product and the
socket buffer sizes.
- for a T3 with 70ms your socket buffer on both endss
should be 450-512KB.
- TCP is also limited by the round trip time (RTT).
- if your application is working in a request/reply model
no amount of
bandwidth will make a difference. The performance is
then entirely
dominated by the RTT. The only solution would be to run
multiple
sessions in parallel to fill the available bandwidth.
- Jumbo Frames have definately zero impact on your case as
they don't
change any of the limiting parameters and don't make TCP
go faster.
There are certain very high-speed and LAN (<5ms) case
where it may
make a difference but not here.
- Your problem is not machine or network speed, only
tuning.
Change these settings on both ends and reboot once to get
better throughput:
[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesTcpip
Parameters]
"SackOpts"=dword:0x1 (enable SACK)
"TcpWindowSize"=dword:0x7D000 (512000 Bytes)
"Tcp1323Opts"=dword:0x3 (enable window scaling and
timestamps)
"GlobalMaxTcpWindowSize"=dword:0x7D000 (512000
Bytes)
http://www.microsoft.com/technet/network/depl
oy/depovg/tcpip2k.mspx
--
Andre
> Marshall
>
>
> On Mar 27, 2007, at 4:26 PM, Philip Lavine wrote:
>
>>
>> To all,
>>
>> 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)?
>>
>> Philip
>>
>>
>>
>>
>>
>>
>>
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>> ______________
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91
>
>
>
>
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