Network virtualization issues

Just several simple things what I got in a seminar.

One of category in virtualization is 'network virtualization' which has not been completely achieved yet.

There are two issues in network virtualization, which are performance isolation and reachability isolation. The latter is supported now in several CPUs, but the former is not addressed yet especially in the area of cloud computing.

The performance virtualization is very critical issue since it can be a bottleneck of QoS in a cloud.