Before you plunk down money for additional bandwidth for your branch and remote offices, consider WAN optimization. This technology delivers significant performance benefits and is a win for tight budgets because it can let IT delay the purchase of larger-capacity connections.

WAN optimization appliances improve use of existing bandwidth by transparently reducing the amount of traffic pumped into the WAN. They smooth over TCP shortcomings via better window management, for example. They optimize chatty upper-layer LAN protocols like MAPI, HTTP, and Windows file sharing.

We surveyed 486 IT professionals who use or have evaluated WAN optimization appliances to find out how they perform. Not surprisingly, Cisco Systems gets invited to the WAN optimization party by nearly half (49%) of respondents, largely because of its ubiquity in enterprise data centers. Riverbed is a close second, with 40%, handily beating out the rest of our field. Citrix, Juniper, Blue Coat, and F5 round out the top six.

Blue Coat, Cisco, and Riverbed have the highest rankings based on 10 evaluation criteria, including product performance and reliability (see chart).