Aug 23

WAN Optimization and WAAS


WAN (Wide Area Network) Optimization is often requested by our clients. They want their circuit to perform better than the TCP/IP (Transmission Control Protocol/Internet Protocol) windows will allow their traffic to. WAAS (Wide Area Application System) is Cisco’s response to this demand. Many of these products look similar, from Riverbed to Silverpeak, but in Cisco’s case the software exists on the router itself instead of a dedicated appliance. This is key when protecting an investment of a Cisco router versus competing products.

WAN Optimization typically becomes a priority once a WAN network is taken across many sites, long hauls, or international. A typical ping from the United States to China is over 200ms. This is a result of distance; the light can only travel so fast. With a delay of 200ms, the circuit performance becomes critical because the introduction of any jitter or packet loss will be dire to the throughput. Companies then install appliances like Riverbed, Silverpeak, or Cisco WAAS to do some of the following functions:

  • Packet Deduplication
  • Forward Error Correction
  • Packet Order Correction
  • Optimize SSL traffic

Utilizing this technology can increase the performance of your circuits and maximize the data transmitted. However, there is a core issue here that we regularly run into with our clients. These devices typically can improve circuit performance by 15-30%. This is a great number, but from an economy of scale perspective, this is relatively small. Increasing a 10Mb circuit by 15% will only add an additional 1.5Mb of throughput.

Some international sites will benefit from WAN Optimization when their existing bandwidth is sufficient. If it is a poor performing circuit, or they are frequently accessing a central file server on a long haul, these are prime candidates. It’s important to note that WAN Optimization is not the right answer for a location that is currently inundating the existing circuits. We need to review the bandwidth utilization, future growth, potential new systems, and the circuit performance. From here was can establish a plan of attack for how best to improve site performance.