“The pain of WAN communications continues to increase as organizations become more dispersed globally, and remote workers increase in number,” said Efi Gatmor, Chief Technical Officer of Expand. “At Expand, our goal is to solve that pain wherever it may be, with technology that has the capacity to be virtually everywhere.”

Recently I had a discussion with Michael Cucchi, Sr. Director of Product Marketing for Expand. Not only have they been adding customers, but they have also added an ROI Calculator to their site (ROI calculator here). It is a web-based version of a more complex tool they use to help customers calculate the savings reaped from making more efficient use of wide area network bandwidth.

The Expand solutions enable network managers to trade CAPEX (capital costs in the form of purchasing WAN optimization boxes) against OPEX (spending less money each month on bandwidth bill from operating the network). WAN optimization has often been viewed as a trade off against bandwidth, but there are other benefits too. With Ethernet WAN services providing cheaper connectivity, it is increasingly obvious that bandwidth isn’t the only issue that affects network and application performance.

While network costs are going down, Michael pointed out that satellite bandwidth costs aren’t on the same price curve. Ethernet WAN services still have a relatively small reach, when you think about them in the context of a global business, or one with many remote sites. Traffic patterns on the network are shifting too. As well as “recreational” peer to peer traffic (read: music and video file sharing), there are a growing number of other IP applications that have peer to peer traffic patterns, for example VoIP and instant messaging. WAN optimization tools like Expand’s are looking to control traffic, as well as providing acceleration. Priority packets can be sent ahead of lower priority ones, boosting performance, and that is before any application-specific algorithms are used to reduce or accelerate the applications.

In all of this, the latency challenge remains – the speed of light isn’t changing, and that is a fundamental hard limit of the time it takes traffic to get from a data centre to a remote office. Applications are dependent on round trip time, and this is another area where WAN optimization can help. Long round trip times, due to high latency, make applications sluggish. That isn’t the only problem, because of the way that TCP works (using acknowledgement packets and sliding transmission windows), that latency can also limit the maximum bandwidth that an application can make use of. It isn’t unusual to see a high bandwidth link under used, because of high latency between a client and the server.

Digging into the Expand offering a little more, they have an interesting licensing model. Products are licensed by upstream bandwidth, that saves money if you are using large amounts of DSL, where the upstream bandwidth is more restricted. Something to bear in mind when costing out solutions. They are also doing a little bit of surfing on the virtualization wave, by providing a solution that can run inside a Virtual Machine. In general their offering seems to reach further than many of their competitors, since they have a server and desktop client. This gives more granular control, by user and application, and also reduces the amount of network hardware, where that is an issue.

The general trend towards desktop virtalization (eg VDI and see the post on VMWare), which is a server based paradigm with servers pulled back from branch into the data centre, means that network performance will become even more critical than it already is. Expand support a broad range of remote desktop protocols, supporting Sun, Citrix, HP and Microsoft solutions (and the open VNC offering).

One issue with adding additional hardware, such as WAN optimization boxes, into the network is potential negative impacts on reliability on performance for non-accelerated traffic. Expand are very conscious of this, and aim to ensure that no packet is on box for more than a 1ms and employ VRRP/HSRP redundancy protocols to deal with failure.

Expand is very strong in Satellite based networks, as well as the obvious applications in server-based computing mentioned earlier. However, businesses with large amounts of mobile traffic might want to investigate their solutions too, since the challenges are quite similar.

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