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Another commonly used technology in WAN Optimization is Compression.

What is Compression?

Compression is the reduction in size of data by converting it to a format that requires fewer bits. Most often compression is used to minimize storage space (on a hard drive, for example) or for reducing transmitted data over a network. By reducing the size of data transferred, more bandwidth is available and transmission times are reduced.

Why should I perform Compression in my network?

Compression technologies are designed to significantly improve bandwidth utilization by minimizing the amount of data traversing the network. Compression can be used in appliances which are deployed as part of a WAN Optimization solution. For WAN Optimization solutions, appliances on each side of the WAN use the ADN (Application Delivery Network) to transfer compressed data between them. This is useful for requests originating at branch offices to servers at the core, but can be even more beneficial for backups that must occur regularly over the WAN.

How does Compression work?
Compression technology uses algorithms to remove extraneous/repetitive information. After compression is applied, the original information is represented by a more compact and efficient format. This “compressed” payload can then be sent over the network. After the compressed data is received at the destination, it is uncompressed based on extraction algorithms. One well known appliance uses the industry standard gzip/deflate algorithm to compress data.

ADN Compression
ADN Compression enables organizations to fully extract every performance benefit available when sending data through an ADN tunnel between appliances. ADN tunnels require that appliances on opposite sides of the WAN be members of the same ADN network and that the upstream appliance either be advertising routes to servers to be accessed by appliances on the opposite side of the WAN, or be deployed inline so that transparent ADN tunnels are possible. Traffic accelerated between clients and servers is automatically compressed before being sent through the ADN tunnel, decreasing bandwidth usage and optimizing response time to the end user. ADN Compression is often used in conjunction with Byte Caching and Object Caching to achieve optimum results. In the case of Byte Caching and Compression, Byte Caching is first applied to the data and then the resulting data is compressed. Both features are enabled by default to optimize ADN directed traffic. ADN Compression for any arbitrary protocol can also be configured on the Blue Coat ProxySG using policy; it can also be controlled separately for both inbound and outbound traffic on the WAN.