Cisco Systems WAE-511

In the drive to bring down operational costs, many businesses are moving away from a distributed data services model. Instead, they're looking to centralise operations at the datacentre. However, WAN performance and application response times must be maintained, and WAN optimisation is proving far more popular than simply throwing more bandwidth at the problem.

Cisco Systems is now moving into this arena. The acquisition of Actoma in late 2004 has allowed it to deliver a unique solution that provides not only WAN optimisation but also WAFS (wide area file services). Cisco refers to this dual approach as WAAS (wide area application services). A key differentiator with products such as Riverbed's Steelhead appliances is that Cisco's WAE (wide area engine) devices don't use proprietary tunnelling methods. Instead, they implement links using native IP. This offers many benefits, especially where VoIP is being used, as it allows QoS to be applied to this traffic type.

The WAE-511 on review targets the SMB, while the WAE-661 and WAE-7326 support medium-level and enterprise deployments. You'll need one at each end of the WAN connection, and they can function either as central core or remote systems. You can implement these products in a non-Cisco environment, but Cisco's ISRs (integrated service routers) also come into the picture, as Cisco offers an optional WAE-NM module, effectively turning it into a complete branch office in a box. Cisco's WAAS implements a wide range of technologies, including protocol proxies for reducing latency, bandwidth management with application proxies, data compression and DRE (data redundancy elimination), optimisation of transport flows, plus, of course, traffic prioritisation.

As with Cisco's Express Catalyst 500 switch, installation doesn't require a visit to the IOS. From a web browser, you can run a six-step quick-start wizard for naming the appliance, assigning core or remote roles and deciding which is to be a WAFS central manager. This allows it to manage and monitor multiple appliances. When a remote server is being brought back into the datacentre, you'd give the appliance the same name. This means that when remote users log on to the server, they're actually accessing it via the appliance but are none the wiser. If one appliance is serving multiple servers, Cisco's WCCP (web caching communications protocol) comes to the rescue, as this allows multiple systems to use different IP addresses but all have the same name.

From the WAFS central manager, you can log on to edge and core appliances, stop or start them and push updates to them. The Connectivity tab is used to define links between core and edge devices, while the pre-position option defines files that you know are going to be required by users and can be pre-cached in the appliance ready for immediate use. The appliances can implement file blocking, so you can stop specific file types from being transferred using multiple policies that contain keywords and expressions. File replication is aimed at disaster-recovery scenarios, so you can ensure that selected data on a server is replicated to another server in a remote location.

There are no half-measures with Cisco when it moves into new territory. The WAE appliances offer a fine range of WAFS and WAN optimisation features. They're extremely easy to install and configure and compare favourably on price with most point solutions.

Author: Dave Mitchell