What You Should Look for in a WAN Emulator Appliance?

With the advent of cloud computing and the Internet of Things, the importance of pre-deployment network performance testing cannot be over-emphasized. Will your app or device perform under all network conditions ranging from the routine to the extreme?

Some apps and devices will simply not work when certain kinds of network conditions occur. Voice communications, for example, generally become unintelligible at certain levels of packet delay that are a common occurrence on today’s Internet!

Best practice is to characterize the full performance profile of the app or device. This way you can avoid inappropriate usage scenarios for your app or device or handle these scenarios with a message to the user that “the network is currently unreachable”.

First, there’s some basics you should cover when selecting test equipment to characterize performance:

1. Will you use a WAN emulator appliance or a conventional network emulator? Do you know what level of accuracy is required for your app or device to function properly? A WAN emulator appliance (a network emulator application operating in a virtualized environment) can eliminate installation and configuration issues, but may not offer the level of accuracy required.

2. How does your app or device respond to packet loss (a frequent occurrence on the Internet)? Can your emulator act as a packet loss simulator? Or, better yet, the emulator should go beyond simulation and actually drop packets (and introduce other common impaired network phenomenon, such as delay, reordering, jitter, etc.) before the packets reach your device or app. so that you can truly understand performance under various packet loss conditions.

3. Another important consideration, particularly in voice and video apps and devices is delay or latency. Can your emulator serve as a latency generator by stepping through all the conditions that are likely to occur that delay the delivery of packets on the Internet?

4. Finally, although it is a little complicated, your emulator should serve as a network bandwidth simulator. You will need to understand how your app or device performs when bandwidth is limited. In addition, there’s a difference between rate limitation and bandwidth limitation.