Enhancing the business through Optimisation

Networks are critical to business - and if the network is slow, so is business. Network managers faced with the challenge of cutting costs while still improving application performance are turning to WAN optimization tools from vendors such as Cisco and Packeteer. Bandwidth or WAN Optimisation is defined as hardware and software that compress data streams, monitor traffic flows, prioritize traffic via QoS, and manage applications from a protocol perspective. In todays Information Marketplace, there are a variety of Optimisation products available to the End User, ranging from Acceleration and caching products to simple Traffic Shaping.

Finding the culprit

The user of a single computer on a dedicated connection will probably know what application has caused a problem or, barring spyware that hides itself deep within a system, figure it out pretty quickly. This task is much harder for a network administrator who often does not know what applications others are running or how the applications use the network.

Typically a single user will not need bandwidth management. The real problem is when multiple users and applications are downloading simultaneously. Because TCP windows are large, these applications all throw a large amount of data into the same queue at your upstream provider. While the traffic arrives at this queue randomly; it is processed sequentially, resulting in choppy download speeds. The more applications that are downloading simultaneously, the larger the backlog. When the backlog grows too high, packets must be dropped to avoid having TCP retransmissions overflow the queue and wasting bandwidth with duplicate traffic. Avoiding dropped packets is the most critical function of bandwidth management.

Troubleshooting network performance is a critical task for network administrators. An individual downloading large files on a dedicated network connection can happily consume as much bandwidth as the network is capable. On a shared network, if one user monopolizes the network, others will complain about any number of things related to the network responding slowly or timing out completely.

Fixing the problem

To keep your Internet connection working fast and smoothly, you must control your use of bandwidth, to stay below the maximum capacity of the network link. To control something, you must be able to measure it.

These tasks are usually viewed separately: much software exists for network traffic measurement and network traffic control, but these are normally not integrated. And indeed it may not be necessary to integrate them. Once the cause of the heavy traffic is identified, it is usually simpler, and may be more effective, and to shut it down or reschedule it than to try to manage its bandwidth use.

Alternatively, the network administrator may decide to increase the amount of bandwidth available which, more often than not, is a costly exercise. However, there is alternatives. Using any of the technologies readily available in the Bandwidth Optimisation market the administrator can control the overall flow of traffic, prioritise mission critical applications (Citrix, Remote Desktop), totally deny peer-2-peer traffic (Kazza, eMule and the like) and effectively slice up the bandwidth pie.