Are you wondering where you can get more documentation for XenServer’s new Distributed Virtual Switch feature? If so, see:

For those of you who are thinking, “Well, gosh, what is a Distributed Virtual Switch?”, XenServer 5.6 Feature Pack 1 introduced a new networking management appliance, the Distributed Virtual Switch, which supports the Open vSwitch standard and let’s you do all kinds of fun stuff like create cross-server private networks.

BTW, the Distributed Virtual Switch is not the default networking component in XenServer 5.6 Feature Pack 1, so if you want to use it, you need to configure XenServer explicitly to do so.