Tools and procedure for Network testing

Hi all,

I just wanted to know how you do your network testing when validating a new design/technology in your Network, especially to ensure that it will meet your SLA requirements for example that a voice call will not be dropped in case of a network element failure ?

Do you test with IXIA, multiping, launch somes VM using ping with -i option, Windows ping by setting the timeout interval, or may be directly from the Network device (routers…),

Many thanks,

I’ve used Ixia on high-confidence projects where we had to prove capacity of an as-built network. Such testing isn’t cheap, but it’s sometimes the only way to get the job done.

Although you can buy Ixia gear and use it in a lab environment, that kind of testing has limited application, because you often can’t fully replicate real world external circumstances.

For a Bay-area airport deployment of several hundred access points, I specified and used Ixia’s Wireless testing platform to verify that we could stream Netflix to several thousand mobile devices simultaneously. The Ixia rigs were made mobile on carts, and each could simulate several hundred simultaneous users. We hired this entire job using Ixia’s own engineers, and it cost about $10K per day for their engineering labor and renting equipment, over several days.

We had to do this simulation in the as-built network ahead of the Thanksgiving holiday, the busiest traffic day at any airport, as part of the proof-of-capacity deliverable. There was no way to prove capacity in a lab environment, due to the many unpredictable variables, such as access point placement, Wi-Fi interferers, and back bone congestion. Another variable was the Internet uplink, which consisted of two 5 Gbps BGP links to two different providers. Even with this equipment, it was impossible to test the entire airport terminal in one go. We did it separate test for the gate areas, and baggage claim, the highest measured device demand locations based on the previous Wi-Fi deployment.

This was the only way to prove the network would not fail in the heat of battle. I have to hand it to Ixia: their people were efficient and professional, and knew what they were doing. There was no way that we as network integrators would gain enough expertise to do this testing in such short order.

-mel via cell

I should add that we did use lab simulation tools to design the network’s AP placement, using Ekahau’s WiFi scanning and design platform, which costs roughly $5k/year to license.

This approach is pretty standard practice in WiFi design: you upload building drawings into the design tool, identify major signal impediments such as walls, low ceilings, aluminized windows, and large metallic RF-reflectors such as baggage carousels. You then use the scanning component to walk the space and pick up and locate all potential interfering legacy APs. The tool lets you specify all construction materials with known attenuation values.

Then you start placing APs on floor plans (these tools have built-in encyclopedias of all major APs and antennas, and knows all their salient characteristics), and generate simulated heat maps, making adjustments after each placement round. These tools also will predict “goodput” and user capacity, and a slew of other metrics. In our case, we discovered that placing many APs close together and at ground level (inside millwork and kiosks) let us exploit “people attenuation” to limit cross-channel interference with high-density crowds. And yes, Ekahau can simulate people as an environmental interferer.

This approach gets you pretty close to the predicted network performance, but when you’re done deploying hardware, the customer typically requires demonstrating the system can reach the designed capacity. This is where Ixia came in. Before choosing Ixia we looked at several other solutions, including bread racks full of Raspberry Pi’s and an amalgam of lower-end test gear. Ixia ended up being the best bang for the buck.


I've used Ixia for similar purposes (nothing related to voip stuff
though), but as others already said equipment cost is a factor here.
If the budget is short or if you're willing to go with an open source
suite for testing, you might want to have a look at Pktgen-DPDK too:

There are tons of tutorials out there explaining how to use Linux +
pktgen-dpdk to generate traffic. I hope it helps.


If the budget is short or if you’re willing to go with an open source
suite for testing, you might want to have a look at Pktgen-DPDK too:
There are tons of tutorials out there explaining how to use Linux +
pktgen-dpdk to generate traffic. I hope it helps.

Without wishing in the least to derail this thread,

would you explain why you (seem to) consider Pktgen-DPDK
as a second, rather than a first choice,
for packet generation?



Another interesting candidate is

Sorry if you thought so Etienne, but I didn't mean to 'suggest' it as
a second-class/second option solution (please note I only mentioned
cost and open source as the factors; I'm sure there are much more to
evaluate!). I just put the options on the table willing to help him to
see what's available out there. It is up to him now to pick X, Y, or
go with ping -i.

This list is really become more and more sensitive these days :stuck_out_tongue:

Ah no, Humberto, I wasn’t offended !

You’re perfectly entitled to choices (as if you needed my saying so :slight_smile: )
and I just wanted to learn more about what criteria drive your preferences.

Thank you for replying.