A recent discussion within the XenClient product management team was around fan out architectures. The idea was how would deployment of managed virtual machines to remote branch offices from a centralized Synchronizer work? Luckily, we work for Citrix. Our colleagues in the Branch Repeater team had the perfect solution – let their appliance do the bulk of the transfer work.

So, we simulated a WAN with a Branch Repeater at either end, and a XenClient device on the remote branch office side and a Synchronizer server on the datacenter side.

The guts of the setup can be a little detailed, but the crux is things JUST WORKED. No special configuration required, no special build of Branch Repeater or of XenClient or of Synchronizer.

We put a Windows 7 OS image on the Synchronizer (see the PoC guide) which was all of 3.3GB after being compressed. The test went as follows with a WAN simulator limiting bandwidth to 12Mbps, RTT of 100ms, and a packet loss of 0.1%:

Step 1. Download VM with both Branch Repeaters disabled. Took about 2 hours and 2 minutes. Not bad considering the WAN parameters.

Step 2. Enable both Branch Repeaters for flow control acceleration. Took about 58 minutes to download the same image. A 50% gain. Not bad at all.

Step 3. Enable both Branch Repeaters for flow control acceleration and compression to disk. Pass 1 took 57 minutes. Expected. Pass 2 took 2 minutes and 55 seconds. A 98% gain.

There is an absolute and expected gain for an enterprise which has multiple branch offices, and wants remote employees to take a full advantage of a managed VM on their XenClient device. This has got to be noteworthy! XenClient simply loves Branch Repeater.