Networking Software Defined WAN (SD-WAN)
3 minute read

Evaluating SD-WAN with Traffic Jam

We have been helping customers evaluate SD-WAN solutions within the ATC for as long as I can remember (Cisco iWAN anyone?). Within every SD-WAN lab, Traffic Jam has been there whether you knew it or not! You might be asking yourself, "What the heck is Traffic Jam?". Traffic Jam at its core is a linux based router. When used in an SD-WAN lab it is typically acting as the service provider that the SD-WAN solutions connect to for underlay connectivity. Within Traffic Jam, you can impair it's interfaces (hence the name), creating sub-optimal scenarios for the SD-WAN solutions so that you can understand how these SD-WAN solutions react and mitigate issues when they arise.

In This Insight

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ATC Insight

The Lab Environment

Before we dive in lets take a moment to review the environment that is under test.  Below is a diagram that represents a pretty typical SD-WAN environment that we use in the ATC.  We have two data centers, two SD-WAN branches, and one legacy branch.  In this environment Traffic Jam is the service provider clouds, Internet (blue) and MPLS (purple).  Traffic Jam provides the WAN connectivity to the SD-WAN solutions.

For this demo we are going to be focusing on Branch 1.  Branch 1 is setup as a standalone SDWAN box that is connected to both Internet and MPLS.

Simulated Application Traffic

Whenever we evaluate these SD-WAN solutions in the ATC we need application traffic flowing through the topology to make the evaluation as life like as possible.  To simulate this application traffic we utilize Ixia.

We have a stock Ixia SD-WAN traffic profile that we use for the majority of SD-WAN evaluations.  Within this stock traffic profile we have the following applications; web (http/https), ftp, and voice (sip/rtp).  

Customers are always particularly interested in the voice traffic because Ixia will report the real-time MOS score as things are happening within the lab environment.  When things start to go sideways the MOS scores will dip.... and sometimes not recover (did someone change something?!?).

The SD-WAN Policy

With SD-WAN you get a certain level of intelligence, the ability to create policy that dictates the path that your applications should take based on criteria that you set.  In this demo we will implement a policy to have all traffic prefer the MPLS path unless latency goes above 20ms.  If the latency goes above 20ms then the SD-WAN solution should shift all traffic over to the Internet path.  If the latency on the MPLS path drops below 20ms then the SD-WAN solution should shift all traffic back to MPLS.

With Traffic Jam you can create the impairment to test this SD-WAN policy and then visually see what's happening to the traffic from the service providers perspective.  Whether or not the policy actually shifted all the traffic over and even how long it took to shift the traffic over.

So let's put this solution to the test!

Demo Time!

The best way to demo Traffic Jam in an SD-WAN environment is to visually see it!  Go to the documentation section of this ATC Insight to view the live demo.

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In the video below we will demonstrate the following:

  • Overview of the Traffic Jam web UI
  • Overview of the Ixia application traffic dashboard
  • Validate SD-WAN functionality via Traffic Jam and Ixia

This video represents exactly what you would see if you were engaged in a lab in the ATC.  We would also have the vendor involved as well showing their dashboards and explaining what's going on as events are occurring in the lab environment.  But enough talk, let's DEMO!  For best viewing experience view the video in full screen mode.

Video Time Stamps:

0:02 - Traffic Jam Web UI Overview

3:30 - Ixia Overview

5:05 - SD-WAN Demo - Introduction

5:31 - SD-WAN Demo - Activate Policy and Observe Traffic Impact

7:00 - SD-WAN Demo - Apply Impairments and Observe Traffic Impact

8:52 - SD-WAN Demo - Remove Impairments and Observe Traffic Impact

9:58 - SD-WAN Demo - Deactivate Policy and Observe Traffic Impact

11:05 - Outro