Compression engine

A compression engine as part of the data center appliance compresses the aggregated packets that are in the highly efficient IP accelerator appliance buffers. This provides an even greater level of compression efficiency, since a large block of data is compressed at once rather than multiple small packets being compressed individually. Allowing compression to occur in the LAN-connected appliance frees up significant CPU cycles on the server where the application is resident.

Overcoming packet loss

The largest challenge in the TCP/IP performance improvements centers is the issue of packet loss. Packet loss is caused by network errors or changes better known as network exceptions. Most networks have some packet loss, usually in the 0.01 percent to 0.5 percent in optical WANs to 0.01 percent to 1 percent in copper-based Time Division Multiplexing (TDM) networks. Either way, the loss of up to one or more packets in every 100 packets causes the TCP transport to retransmit packets, slows down the transmission of packets from a given source, and re-enters slow-start mode each time a packet is lost. This error recovery process causes the effective throughput of a WAN to drop to as low as 10 percent of whatever the available bandwidth is between two sites.

IP application accelerators optimize blocks of data traversing the WAN by maintaining acknowledgements of the data buffers and only sending the buffers that did not make it, and not the whole frame. This allows for the use of a better transport protocol that will not retract data or move into a slow start mode. Using a more efficient transport protocol has lower overhead and streams the data on reads and writes cycles from source to destination. This is completely transparent to the process running a given server application.

Caching

Web documents retrieved may be stored (cached) for a time so that they can be conveniently accessed if further requests are made for them. There is no need for the entire data to move cross the network and only updating requests are sent across, thereby optimizing network bandwidth.

Server load Balancing

Server load balancers distribute processing and communications activity evenly across a computer network so that no single device is overwhelmed. Load balancing is especially important for networks where it is difficult to predict the number of requests that will be issued to a server. Busy Web sites/Web sites with a heavy traffic typically employ two or more Web servers in a load-balancing scheme.

SSL acceleration