WaaS Express is a lightweight version of Cisco's Wide Area Application Services appliances. It runs natively on the ISR G2 router without requiring the additional Services Ready Engine SRE blade to be installed. WaaS Express capabilities include TCP flow optimizations, LZ compression and data deduplication. However, WaaS Express doesn't support any application layer optimizations available for MAPI or CIFS on the WaaS appliances. To run WaaS Express, the ISR G2 will need additional RAM: 2.5GB on the 1900, which will cost approximately $500, and 4GB on the 3900, which will cost approximately $1000. WaaS Express is a license feature ranging from $1000 to $2500, list.
Cisco claims that WaaS Express can double the WAN bandwidth for a fraction of adding a competing WAN optimization product. Riverbed's low end Steelhead 250 starts at $3,200 for the street price, while Silver-Peak's NX-2600 runs approximately $4,300, but that gets you the appliance and the hardware. While a Cisco ISR 1900 can start as low as $1,500 street, when you add in WaaS Express at $2,500, it starts to add up.
Also, don't expect the kind of long term benefit of deduplication that you get from dedicated WAN optimization appliances, Cisco or otherwise, because total RAM for the deduplication component in WaaS Express is very small. Even Riverbed's 250 appliances have 40GB of disk storage. The performance increase by WaaS Express is likely due to come primarily from compression and TCP optimizations that make TCP more efficient. WaaS Express is managed by WaaS Central Manager and provides an upgrade path to vWaaS running on the ISR G2 SRE blade or even on a WaaS appliance.
Cisco has also announced UCS Express, which allows the SRE blade to run a hypervisor so that virtual machines can be installed remotely and they can be managed using the UCS Manager--the same manager that runs the flagship Unified Compute System (UCS) server line. Previous versions of the SRE required someone on-site to install new services on the SRE blade, which makes for a costly upgrade. Now, the ISR can be shipped with an SRE blade to the remote site and applications can be selected and installed at a later date. UCS Express starts at $2,795 and will be available in November, 2010.