[netperf-talk] HELP:Regarding iANS test using netperf

[Rick Jones]

>  As part of our project we needto use netperf tool to check the iANS's
> performance.Here comes the topology.
> 
>     IO SERVER-----------(two kilomega twisted pair --------CISCO4506
>  (with large storage)      wire,bonding by iANS)               | | |
>                                                                | | |
>                                                                | | |
>                                                                | | |
> One of client node------(single kilomega twisted pair)---------  | |
> One of client node------(single kilomega twisted pair)-----------  |
> .    .   .                                                         |
> .    .   .                                                         |
> .    .   .                                                         |
> One of client node-----(single kilomega twisted pair)--------------
>  
>  
> *******************************************************************
>  
> First I test one IO server to one client node,the result as below
> (IO server set to be test-server)
> [root at rack64 src]#  netperf -H 192.168.77.8 -l 60
> TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to xinnode3
> (192.168.77.8) port 0 AF_INET
> Recv   Send    Send                         
> Socket Socket  Message  Elapsed             
> Size   Size    Size     Time     Throughput 
> bytes  bytes   bytes    secs.    10^6bits/sec 
>  87380  16384  16384    59.99     904.44  
> 
> That looks like OK.
>  
> But when I try to use two client nodes 'netperf' the test-server in the 
> same time ,the results comes like this :
>  
> [root at rack61 netperf-2.4.1]#  netperf -H 192.168.77.8 -l 60
> TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to xinnode3
> (192.168.77.8) port 0 AF_INET
> Recv   Send    Send                         
> Socket Socket  Message  Elapsed             
> Size   Size    Size     Time     Throughput 
> bytes  bytes   bytes    secs.    10^6bits/sec 
>  87380  16384  16384    59.99     470.13  
>  
> [root at rack60 netperf-2.4.1]#   netperf -H 192.168.77.8 -l 60
> TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to xinnode3
> (192.168.77.8) port 0 AF_INET
> Recv   Send    Send                         
> Socket Socket  Message  Elapsed             
> Size   Size    Size     Time     Throughput 
> bytes  bytes   bytes    secs.    10^6bits/sec 
>  87380  16384  16384    60.00     473.04  
>  
>  
> ************************************************************
> 
> The IO server  suppose to be a powerfull one which can provide 2000 
> bits/sec, but according to the test result,it just about 940 bits/sec.
>  
> what can I do ?

You need to look into the specifics of the algorithms used by iANS on 
either end to do the bonding.  What fields of packet headers does it 
examing when determining on which of the links it should send a packet - 
in each direction.

For example, if the Cisco side is looking only at destination IP 
address, then it doesn't matter how many connections are coming to that 
one IP address, they will all be put over the one link.

Most bonding/aggregation/trunking solutions, at least those in their 
right minds :)  will not spread the packets of a given "flow" across 
multiple links - otherwise the packets in that flow could be reordered 
and that would be bad.  So, if the device(s) in question define a "flow" 
as the destination IP...

rick jones