Know your data

When networks were isolated, data traffic was not a matter of discussion as much as it is now. Nobody ever wanted to know what data is flowing on the LAN (Local Area Network) and why. This resulted in a number of network applications that inefficiently used the network bandwidth but still continued to enjoy a prominent slot in the enterprise application bunch due to lack of awareness or concern. With the advent of the Internet and connectivity to the Internet getting popular, these applications were either rewritten or newer network efficient applications took over as managers realized the need to use the precious little bandwidth that they had, very effectively. Network aware applications do make a conscious effort to use the wide area bandwidth efficiently. This was just the beginning of the efforts to manage the wide area bandwidth at the enterprise level.

From what used to be an occasional activity, the effort of managing bandwidth is slowly becoming an important daily activity. This is because there a lot of applications that are freely available on the desktop and the recent spate of viruses have just left a number of networks gasping for breath. There are security tools on the enterprise network like firewalls, intrusion detection systems besides anti-virus software on the desktops. These tools help maintain some level of control over network traffic but they cannot and are not intended to help control the network bandwidth fully. The fact that some of the recent viruses used known TCP (Transmission Control Protocol) ports makes the task even more challenging.

The first step towards getting a grip on this problem is to do traffic discovery on the network and understand what the data that is flowing on the network on a normal day is. Traffic discovery and doing a benchmark for the amount of data that is generated by serious business applications and other office automations applications like mail during a normal day would come in handy to troubleshoot traffic patterns when there is a surge in the traffic. An alternative to doing traffic discovery is to use some of the traffic statistics capabilities that are available on most of the well-known routers.

The next step would be to configure and install a system that would give an alert when the normal traffic patterns are violated by any of the application traffic. For example if there were excessive HTTP (HyperText Transfer Protocol used by browsers) traffic on the network then the system would alert the IT department on the changed traffic patterns. Some of the systems also detect change on any of the traffic patterns including unknown traffic and can help initiate control measures fairly quickly.

In today's network, traffic shapers are common while traffic analyzers are getting to become popular because of the significant changes in the network traffic patterns that are being observed on networks randomly. These traffic analyzers also can provide a very good idea of the network utilization and can help zero-in on erring bandwidth unfriendly applications.

A quick way to get started is to start looking at some traffic data from the routers while you work on the other activities involved. Once you have some data to look at, I am sure you will get engrossed in knowing your data in much more detail !

- C.R. Srinivasan