Compression box boosts network bandwidths

Compressing wide area network traffic has always been technically possible, but has not been widely implemented. A new device from Peribit could help change that

A product that claims to make it easy and cost-effective to compress wide area network (WAN) traffic and save money is now available in the UK. The Peribit SR-50 is a standalone box that effectively turns 256kbps lines into 1mbps lines. It has been available in the US since September. Compression has been understood for a long while, and regularly applied on disk storage and modem lines. However, on faster corporate networks it has often been left unapplied, because of the processing overhead and delay (latency) caused by compression, and because it is usually incompatible with the encryption that many businesses now require on WAN traffic. Peribit claims to have overcome these issues. If there is any breakthrough, however, it is in the packaging of the technology into a product, rather than the underlying technology. Peribit's marketing literature emphasises the algorithm it uses, which was derived from founder Amit Singh's Ph.D work on DNA sequencing. However, this technology is more realistic than some wild claims that the compression field has been plagued with, and is in fact a clever but conventional algorithm. Compressing WAN traffic has always been technically possible, but has not been widely implemented. More importantly, the box is designed to be easy and to deliver noticeable paybacks. One version, which can fill a 256kbps link (with up to 1mbps of uncompressed data) costs $16,000, while the 45mbps version costs $64,000. They are installed in the network and make contact with each other automatically, so they can selectively compress traffic destined for sites where a Peribit system is installed, setting up "reduction tunnels" between them. "You set the box up and FedEx it to your remote office. They power it up and it automatically discovers the other Peribit systems on the corporate network," said Singh. Other features include failure-to-wire, which means that if the device fails, the network link is still up -- although uncompressed. "We have sold around 130 boxes," said Shane Buckley, president, Europe, Middle East and Africa, for Peribit. "Some customers have seen 90 percent reduction." The main competition Peribit faces is from the compression options within Cisco routers themselves. Cisco's IOS includes a software compression feature, which is only suitable for low-speed links, and hardware acceleration modules can be added to all small-to-midrange Cisco routers, for a price starting at $1500. "Around 15 to 20 percent of our financial sector customers have bought hardware compression modules," said Malcolm James, product manager, EMEA, for Cisco. "Banks are more interested as they have many remote sites." However, Cisco's approach of compression in the router is ineffective on traffic that has been encrypted before being passed to the WAN -- an increasingly popular option. Encrypted traffic has had all patterns obscured, as well as preventing snooping, it also prevents compression. "I am finding that organisations are foregoing the benefits of compression in favour of encrypting their data," said James. Peribit's stand-alone approach scores here. As a Layer 3 compression box, it can operate on data before it is encrypted. An Internet standards body, the IETF, has created a standard: IPPC for Layer 3 compression, which will allow traffic to be compressed before it is encrypted. Cisco has implemented this, but so far only in software running on its routers, so it is still not possible for Cisco equipment to compress traffic before encryption, admitted James: "We are in the process of developing a hardware compression device, but the standard was only published recently."

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