Packeteer is buying Tacit Networks to add important server consolidation technology to Packeteer's WAN-optimization products.

Initially, the $78 million cash deal will add Tacit's IShared devices to Packeteer's product line of PacketShaper and SkyX Accelerator appliances.

In all cases, these devices are deployed in pairs at both ends of WAN connections. Each performs different functions to speed up transactions across the links. Customers would choose which products to buy based on their particular needs.

The way Packeteer sees it, customers would buy PacketShaper devices to get a read on traffic among their sites and determine which applications need help and which products would best help them.

Over time, Packeteer plans a new set of hardware that would support both PacketShaper and IShared software so customers could buy one device and upgrade it as needed with additional software and possibly additional disk space.

Packeteer identifies gigabyte caching and branch-office support for DNS, DHCP, printing and domain services as key to server consolidation. When servers are pulled out of branch offices and centralized, devices are needed to support these services in the branch. And as servers are centralized, caching data is also important to keep response times low when branch-office users request data. Tacit's gear supports all of these.

IShared devices connect remote and branch offices to improve wide area file services (WAFS) to the data center and synchronizing their file operations. Its IShared Server sits in the data center, and IShared Remote sits in the remote offices. Changes to files in the remote office are synchronized with those of the data center. Access to files for remote offices happens just as fast as if they were connected on the LAN.

Tacit gear can also protect data so when a WAN link goes down, remote users still can access files that have already been cached on their end. Customers can modify files and create new ones in the local cache. When the downed links come back up, IShared boxes will re-synchronize the files with the server where the files permanently reside.

PacketShapers view and analyze applications, control quality of service, compress traffic and accelerate specific applications. They also perform caching in RAM on the megabyte scale - more fragments than entire large files.