Visual Networks announced software that adds application monitoring to its smart CSU/DSUs, making it possible to better pinpoint whether application delays are based on network problems.

Called Select AppSummary and Select AppFlows, the software analyzes data that Visual devices called ASEs already gather to show which machines on the network are involved in what types of sessions with what other machines.

This data is now manipulated to reveal what machines are the source, for example, of spikes in traffic of a particular kind. This gives network administrators a tool for tracking down whether congestion is caused by legitimate traffic, unauthorized traffic or even worms and viruses, Visual says.

In the future, this capability could be shared with security enforcement devices such as firewalls to block the flows that cause problems, the company says.

One drawback is that the devices cannot determine what application is involved in encrypted sessions.

Select AppFlows and Select AppSummary are software modules that customers can activate via licensing keys they buy from Visual. The keys can turn on the capabilities permanently or for a set period to deal with a particular network problem. 

Select AppFlows costs $1,500 per site, and Select AppSummary costs $500 per site. Both together cost $1,700.