[c-nsp] Performance issue on link

[Tony]

Try using multiple TCP sessions  "iperf -P 5"  (note - capital "P").


regards,
Tony.





----- Original Message -----
> From: CiscoNSP List <cisconsp_list at hotmail.com>
> To: Azher Mughal <azher at hep.caltech.edu>
> Cc: "cisco-nsp at puck.nether.net" <cisco-nsp at puck.nether.net>
> Sent: Tuesday, 2 April 2013 9:51 AM
> Subject: Re: [c-nsp] Performance issue on link
> 
>T hanks - Ill check them out now
> 
>>  Date: Mon, 1 Apr 2013 16:16:36 -0700
>>  From: azher at hep.caltech.edu
>>  To: cisconsp_list at hotmail.com
>>  CC: cisco-nsp at puck.nether.net
>>  Subject: Re: [c-nsp] Performance issue on link
>> 
>>  These might be helpful:
>> 
>>  http://fasterdata.es.net/network-tuning/
>> 
>> 
> http://www.mellanox.com/related-docs/prod_software/Performance_Tuning_Guide_for_Mellanox_Network_Adapters.pdf
>> 
>>  -Azher
>> 
>>  On 4/1/2013 3:51 PM, CiscoNSP List wrote:
>>  > Hi,
>>  >
>>  > We have a 40Mb link between 2 POPs - Latency ~65m/sec (No packet-loss)
>>  >
>>  > POP A Is a 7301 and 2960POP B is a 7200 and 4948
>>  >
>>  > 40Mb link is connected to the two switches (L2), and then a trunk link 
> to both routers for all L3.
>>  >
>>  > Have a Linux server connected to both switches, and achieve the 
> following performance:
>>  >
>>  > IPERF (UDP)
>>  > POP A -> POP B - 38.5Mb/secPOP B -> POP A - 38.5Mb/sec
>>  >
>>  > IPERF (TCP)
>>  > POP A -> POP B - ~20Mb/secPOP B -> POP A - ~12Mb/sec
>>  >
>>  > FTP
>>  > POP A -> POP B - ~38Mb/secPOP B -> POP A - ~16Mb/sec
>>  >
>>  > WGET
>>  > POP A -> POP B - ~30Mb/sec POP B -> POP A - ~16Mb/sec
>>  >
>>  > Any suggestions on why I am seeing poor performance with TCP 
> transfers? (Especially POP B -> POP A direction) - I've tried adjusting 
> the window size in IPERF but it actually made the results worse?
>>  > Thanks in advance.
>>  >