Im currently looking at the necessary TCP settings I could use to increase the throughput of a WAN link. The current download speed is 1.78Mbps and a ping is showing a 300ms RTT. So far the following settings I was thinking of deploying were SACK and Nagle. However Im not sure what the Window Scale should be set to (or if used at all). Im also thinking of lowering the MTU based on the PMTU to avoid any fragmentation, but still waiting on confirmation on the PMTU. Does anyone have any thoughts on the above or if there is anything Im missing. Thanks..... asked 21 Mar '13, 09:47  bart80 |
One Answer:
SACK is always good to have, Nagle can help with utilization if you don't need shortest possible latency. Scaling only needs to be enabled if the optimum window size for that WAN link is larger than 64k. You can calculate the optimum window size by multiplying the RTT in seconds times the slowest connection speed in bytes that happens on the link. For example, a RTT of 300ms and a 10MBit link would get you 0,3s x 1,250,000 byte = 375.000 byte window size. In that case you'd need to enable window scaling to be able to get to that window size. answered 21 Mar '13, 10:41  Jasper ♦♦ edited 22 Mar '13, 09:44 |
Just a quick update , that based on making these updates I managed to get 3 times the speec that we were previously getting,
Thanks...