"When the government says it is putting in the NBN and it is going to give blindingly fast access to everybody they are forgetting that big bandwidth does not give speed unless your fundamental problem is congestion, but if congestion is only one cause of slowness the NBN is going to do nothing for access," Steve Dixon, managing director of Riverbed for Australia and New Zealand, said.

"The government is making this promise of blindingly fast speed and there will be an awful lot of services that will see no improvement at all, so there could be a huge backlash."

"If the government were thinking intelligently instead of rolling out fibre for the next 10 years they should be saying 'let us look at this intelligently and maybe the deployment of optimisation products would meet the objectives they want and the could do it very quickly."

According to Dixon, latency combined with the very high level of dialogue inherent in Internet protocol traffic - and in many applications that operate over wide area networks - combine to restrict throughput to a fraction of the available bandwidth.

"If you have a link between Sydney and Brisbane you will have latency because of the distance, because of the tail ends and because of all the pieces of equipment the data has to go through. That latency will have a direct impact on performance. To achieve anything on that link requires data to make hundreds of thousands of round trips. The way TCP works is to send a bit wait for acknowledgement and then send a bit more.

"In an extreme case, if data were sent in 16 kilobit blocks and the round trip time was one second then no matter how fat the pipe throughput would be only 16 kilobits per second."

Dixon gave a real world example: "A large financial services company put in a one gigabit per second link between Sydney and Brisbane for data centre duplication but the maximum throughput they were getting was 24Mbps."

He added that the same company also had a problem with branch connectivity. "They were opening branches at a rapid rate but sometimes they could not get the leased lines into their buildings in less than three months. They found that plugging our [wide area network] optimisation appliance into a router with a 3G interface they were getting an [effective] 30-40Mbps. It gave them such high performance the did not need to consider putting servers in each branch." So over that 3G link they were getting better performance than over that one gig link.

Deployment and use of optimisation technology such as Riverbed's in networks that are open to public access would represent a radical departure from the way the equipment is presently used, but according to Dixon this would present no barrier to his company's technology because Riverbed appliances and software automatically discover each other if a communications session is established between.

"Our idea is that we would stick racks and racks of this stuff into data centres and if you happen to be a Riverbed customer and you access one of these sites the two boxes will discover each other and start optimising," Dixon said. "And the smart thing will be when we see it turning up in the PoPs of service providers."

However while Riverbed's technology incorporates multiple techniques for optimisation, including repackaging data into larger 'blocks' to reduce the impact of latency, it achieves its biggest gains by simply not sending most of the data.

According to Riverbed's web site: "Steelhead appliances transparently intercept and analyse all of your WAN traffic. TCP traffic is segmented, indexed, and stored as 'segments' of data, and the 'references' representing that data are stored on disks within Steelhead appliances on both sides of your WAN. Once the data has been indexed, it is compared to data already on the disk. Segments of data that have been seen before are not transferred across the WAN again; instead a reference is sent in its place that can index arbitrarily large amounts of data, thereby massively reducing the amount of data that needs to be transmitted. One small reference can refer to megabytes of existing data that has been transferred over the WAN before. Data Streamlining is highly scalable, with peak data reduction ratios that can be as high as a 100:1, and sometimes even higher."

This technique is likely to me more effective in a corporate network - where the same data in modified forms flows back and forth across the network many times - than in the public Internet.

Dixon acknowledged that Riverbed's technology had to have previously 'seen' content before to deliver the full optimisation, but suggested that its installation at 'staging points' in service provider networks, close to end users, would greatly improve performance simply through its ability to mitigate the affects of latency over the long haul sections of communications links.