-First, you have to add your node to the nodegroup "umts" [1]. In this
-way the host environment of the node will get the tools needed to
-manage the 3G umts/hsdpa interface. Then, you have to add the vsys
-attribute to the sliver you want to grant the access to the umts/hsdpa
-interface. The value of this attribute ("vsys") has to be set to
-"umts_backend"
+With the OneLab distribution, you need to add 'umts' to the
+'extensions' tag of your node; this tag contains a space-separated
+list of software extensions to be installed on a node, so that your
+nodes has the tools needed to manage the 3G umts/hsdpa interface. This
+needs to be done before you install your node. Note that with the lxc
+distribution this code now is shipped on all nodes so there is no need
+anymore to deal with the 'extensions' tag.
+
+Then, the slivers (or slices) you want to grant access to the
+umts/hsdpa interface need to have a 'vsys' tag named 'umtsd'.