This article can also be found in the Premium Editorial Download "Storage magazine: Comparing EMC Symmetrix DMX-3 vs. Hitachi Data Systems USP1100."
Download it now to read this article plus other related content.
Skinny pipe TCP WAN optimization plus WAFS
Skinny pipe TCP WAN optimization and WAFS are often features and functions of the same WAN optimization controller. Skinny pipes are defined as bandwidth less than 5Mb/sec; typically, they have a bandwidth of 1.5Mb/sec (T1) or less. Skinny pipe TCP WAN optimization is functionally similar to DRO; the key difference--and it's not a trivial one--is the size of the bandwidth pipe. Algorithms and techniques that work with fat pipes don't work nearly as well with skinny pipes and vice versa. Skinny pipe TCP WAN optimization has effective data throughput results similar to DRO.
Vendor methods vary, with widely differing results depending on the data. In general, vendors use some combination of deduplication, compression, sequence caching, TCP and UDP acceleration, bandwidth management, multithreading, quality of service (QoS) and path optimization.
WAFS goes a step further by providing acceleration for specific applications such as CAD/CAM, print, Web caching, e-mail, DBMS or enterprise resource planning. The combination of skinny pipe WAN optimization plus WAFS is an outstanding way to centralize ROBO data. One way WAFS radically improves the performance of some of these apps is by reducing the application protocol's "chattiness."
The Common Internet File System (CIFS) is an excellent example of a very chatty application protocol that requires numerous commands for every transaction. Each command creates
Skinny pipe TCP WAN optimization plus WAFS is an excellent choice when there are quite a few ROBOs, the bandwidth to the ROBOs is less than 5Mb/sec and performance comparable to that of locally hosted applications for ROBO users is important. Skinny pipe TCP WAN optimization plus WAFS isn't a good choice when the amount of data moved between locations is very large or for laptop mobile users.
This was first published in January 2007