TCP Stacks comparison with a single stream Bulk throughput measurements| Bulk throughput simulation | Windows vs. streams | Effect of load on RTT and loss | Bulk file transfer measurements | QBSS measurements | Internet 2 Land Speed Record  Fabrizio Coccetti and Les Cottrell. Created 24 Feb '03, last update 19 March '03

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From Sunnyvale to Geneva

For all measures  MTU=1500Bytes and txqueuelen=100packets.
We run pings during the measures to verify that RTT stays almost constant

Fast TCP performance analysis

When we compare these throughputs with those measured with 1GE interfaces on other hosts at Sunnyvale, it is apparent that FAST TCP performance was poorer on SNV19. Our understanding is that FAST is not able to achieve high thruput on the Sunnyvale machine SNV19 because the SysKonnect card was plugged into a 33 MHz PCI slot. On machines where SysKonnect cards were in 66 MHz PCI slots, FAST had no problem achieving > 900 Mbps. I had verified this during our 10GbE test last week. I believe we were running into some bottleneck with the 33Mhz (64 bit * 33 Mhz ~ 2 Gbps) PCI that created a delay that was interpreted by FAST as queueing delay, hence the slower throughput. Cheng Jin.

Scalable TCP performance analysis

Scalable TCP is expected to reach almost the same performance of HSTCP.  An explanation of their different behavior, in our tests,  is given by Tom Kelly.  "The HSTCP experiments are conducted with the wad_ifq variable set to 1. The Scalable TCP experiments appear to not have the equivalent tx_moderate_on_txq variable set to 1. The reason Scalable TCP does not have this parameter set by default is that it ships with a txqueue default of 3000. If txqueue is reduced it is advisable to set tx_moderate_on_txq to 1 to achieve reasonable performance.".

From Sunnyvale to Amsterdam

For all measures  MTU=1500Bytes and txqueuelen=100packets.