Optimising inter-campus WAN link performance

by Haris Chaudhry, Network Systems Engineer at Computelec

In this post, I will be looking at WAN Acceleration, and how it can increase the efficiency and speed of your existing WAN links.

What is WAN acceleration?

WAN (Wide Area Network) Acceleration is a means of increasing the data-transfer efficiency across a WAN link. The most common measures of TCP data-transfer efficiencies are throughput, bandwidth requirements, latency, protocol optimization and congestion as manifested in dropped packets. Another great feature of WAN acceleration is packet loss recovery.

The problems at most multi-campus schools

We meet a lot of schools who have problems with the throughput of their inter-site WAN links. Generally we find that they are oversubscribed, but the problem also exists with MPLS circuits in a scenario where the school campus is geographically too far apart for a microwave/Radio link. File level replication (such as DFS) adds even more overhead to the problem. Offsite backup systems are also affected by this problem.

How can we optimise these slow WAN links?

The solution for optimising slow WAN links lies within WAN Acceleration. Typically this is a device that sits on both ends of a WAN link. The data that passes through the device is compressed and de-duplicated, and on the other end the data is decompressed on the fly.

There are a few topologies that can be used with WAN acceleration devices, as below:

Point-point Topology

This is a basic topology that has two sites communicating over a wan link. There are WAN acceleration devices that sit on the edge of both sites doing the compression and deduplication.

Star Topology

This is a scenario such as Computelec EISS, or Managed Services, where sites connect to a central datacentre. WAN acceleration is performed on both ends to ensure maximum performance. Customers can expect 300% - 900% increase in throughput which is extremely useful for off-site backup replication.

Summary

In summary, WAN acceleration is a very effective way to get more efficiency and speed from your existing WAN links. After WAN Acceleration alone, we have seen schools gain up to 10X increase in through put.While we have only shown two scenarios in this post, there are many other ways to optimise your school’s network. If you have any questions about the above or School Networking in general, please get in touch!