Business Case

When it comes to corporate networks, no organisation wants to throw out its existing infrastructure. Prior to the advent of the bandwidth-hungry applications already outlined, networks - generally using 64K or 128k leased lines between the branch and head office - were capable of supporting the business's critical applications.

Yet with data traffic doubling every six months, including a rapid escalation in the amount of email traffic flowing between branch and headquarters, an enormous strain is being placed on existing corporate networks.

Upgrading bandwidth is an expensive business. A simple upgrade from 128K to 256K leased line can cost an organisation an extra £5,000 per branch per annum. In comparison, a comparable overlay network solution could cost approximately £200 per branch in transmission costs. In general, organisations implementing overlay networks can recoup their investment within a year.

For example, imagine a branch office of an enterprise, each with 100 end users, wanting to distribute new virus software. Using traditional 'one-to-one' distribution, a file update would be sent sequentially from the centre to each of the 100 PCs. With an overlay network, the same file updates are sent as one data stream to a branch-based server appliance, which distributes the content simultaneously to its 100 end-users. This reduces the bandwidth required for the task to a small fraction, as little as 1%, of that previously required.