I guess the NetworkBandwidth element defines a maximal bandwidth of a networking interface for a given resource. Such a 
metric is often useless in a resource selection process because indeed only the actual bandwidth between two specific 
nodes really matters. Even if a machine provides a large theoretical banwidth it does not make any sense to select it 
for a job submission if, for instance, another machine in the user's local network can be used. So it would be useful to
 enable the NetworkBandwidth element to define a bandwidth between two nodes, e.g. by adding an optional attribute to 
specify the second node. Of course, this can also be added as an extension.
The element could look as follows:

<IndividualNetworkBandwidth externalNode="xsd:string">
   jsdl:RangeValue_Type
</IndividualNetworkBandwidth>?