Hello,
I am doing some tests to measure the throughput that can be expected for CIFS applications while using WAAS optimizations.
On the tests are involved a windows 2K3 server and a WIndows XP client. The RTT between XP client and the WAAS is around 4ms and the RTT between WAAS peers is around 10ms. THe link between WAAS peers has a bandwidth of 30Mbps, and both WAAS peers are implemented in inline mode with forced ports on 100Mbps full. No prepositions are configured on WAAS. The version WAAS are running is 4.3.1.
While Copying files from Local (Windows XP) to Remote (Windows Server 2k3), on passthrough the throughput achieved by CIFS is around 15Mbps.
Even when applying TFO, LZ, DRE or other Optimizations Combinations (not CIFS acceleration), the throughput is almost the same. That comes because CIFS sends the write requests on a sequencial order, and would wait for a Write Response before Sending another SMB block. Thats why even when OPtimizations are implemented, we wouldnt see improvements on CIFS throughput, since the Original CLient (Windows XP), would not send another SMB block without first getting Write Response for the Previous SMB Block sent. However there would be a lot of Compression on the Bandwidth occupied on WAN.
THe things change when CIFS AO is applied. In this case WAAS would resond locally to the Write Requests, so the original Client would send another SMB block. Then WAAS would send these
blocks on the other WAAS peer concurrently, so it could occupy all the bandwidth available. In this way the CIFS throughput achieved would be bigger than when CIFS AO is not applied. However this throughput would depend on how many Local Responses would WAAS send to the CLient without getting the REAL response from the original Server (WIndows 2k3).
My question is:
How many Local Responses can CIFS AO sent without getting the REAL response? In my case i achieved a CIFS throughput of around 25Mbps when Only TFO and CIFS AO was applied, and a throughput of around 27Mbps when Full Optimize and CIFS AO was applied. I had 99% compression when FULL OPtimize was applied (mainly by DRE). May be there is a buffer where CIFS AO would write this data and keep them until they are acknowledged by the original Server. Could I know where could I see the size of this buffer?
Best Regards,
