WAN Accelerators are wonderful tools in improving your network performance, provided your traffic can benefit from this technology.
If you obtain an MPLS network, your network performance will be better than a VPN over the internet. But you need to select your Classes of Service appropriately. Different CoS levels have different packet loss SLAs. On a simple level, the SLAs might be:
- Basic CoS: 99.9% packet delivery
- Middle CoS: 99.99% packet delivery
- Best CoS: 99.999% packet delivery
If you decide to subscribe to all Basic CoS, the SLA is 99.9% packet delivery. That is typically the same as an uncongested internet access circuit, so you might not see any performance improvement. But if you use your WAN Accelerator with the Middle CoS with 99.99% packet delivery, you will experience a more noticeable improvement. Obviously, the Basic CoS will work better than the internet when the internet is congested, since the MPLS network avoids those bottlenecks.
When using a WAN Accelerator, since you are using compression, if your compression ratio is 20:1, if you lose 1 packet, you are really losing 20 or more packets. So you maximize performance with a network that has less packet loss/better packet delivery.
To reduce or eliminate the number of undelivered packets, select a higher CoS.
One thing you should be aware of, that is not widely publicized is that the lower level Class of Service levels will not provide the expected performance improvements when you use a WAN Accelerator. But if you design your network accordingly, you will be very pleased with the performance boost.