Network Emulation

Document created by DPM Admin Employee on Jul 20, 2017Last modified by Jijius Jabez on Aug 9, 2017
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As of SOASTA 57, Network Emulation helps ensure your load tests match real-world workloads and user experience as closely as possible, to ensure the quality and availability of your network(s). Network Emulation alerts packet flow, performance, and availability to replicate the behavior of real-world networks.

As mobile continues to grow, measuring the performance of network types that customers encounter is important. Packets will be dropped and requested when a user's device loses and regains connectivity, respectively. Network congestion causes jitter, and impacts packet delivery.  

Prerequisite for Azure Users

If you use Microsoft Azure for network emulation, you must choose the servers at the Azure RM locations. 
Note that the network emulation is unavailable on the servers at the "Windows Azure IaaS" locations.

For information about Microsoft Azure as a Cloud provider, see Setup Microsoft Azure as a Cloud Provider Account.


Creating a Network Emulation Profile

The steps below explain how to add new Network Emulation Profiles. You can always skip to the next section, Built-in Network Emulation Profiles, and use a built-in profile as is or build upon it.


Note: Network Emulation will apply on top of the physical network conditions that CloudTest runs. The conditions of your physical network impact network emulation. For example, network emulation can’t simulate a connection faster than your physical network connection.


  1. Log into your CloudTest instance, click Network Emulation Profiles in the Central tab, and select create new.
  1. Name and add a Description (optional) of the network emulation you want to create.

  1. Select a Network Type with a connection type. Choose a custom network type or choose between the following network types:
    • WiFi
    • 2G
    • 3G
    • 4G
    • DSL
    • Cable
  1. To correspond with your Network Type, choose a custom connection speed or choose between a:
    • Good Connection
    • Average Connection
    • Poor Connection
Network Emulation Upstream/Downstream Parameters

There are five sets of network emulation parameters for downstream and upstream.

  • Latency is the delay of network traffic.
    • Jitter is an optional parameter providing a delay variation with a correlation.
    • Distribution is the delay distribution model. Select a uniform, normal, pareto, or paretonormal distribution.
      • Uniform: Symmetrical and equal probability of distributions.
      • Normal: Continuous probability distribution that closely represents real-valued variables.
      • Pareto: Heavy-tailed and often skewed distribution.
      • Pareto Normal: Combination of both pareto and normal distributions with 75% pareto and 25% normal distribution.
  • Bandwidth is the rate of data transfer (select a unit of measure). Bandwidth availability depends on your physical network.
  • Packet loss adds an independent loss probability to your network emulation. Optionally, add a correlation to packet loss.
  • Corrupt helps emulate random errors. Optionally, add a correlation to the corrupt option.
  • Duplicate packets can be emulated with an optional correlation.

Built-in Network Emulation Profiles

There are over multiple (37) built-in Network Emulation  Profiles available on CloudTest. These templates use average numbers to emulate real-world networks. You can use a built-in profile as is, or as a template and build upon it clicking on Create a New Profile From This Template.

To open a built-in profile, select Network Emulation Profiles in the Central tab and select one of the profiles listed on the right.

Setting Network Emulation Profiles in the Composition Editor

In the Composition Editor, you can easily: set your own Network Emulation Profiles, select built-in profiles, or create new profiles.

Network Emulation can be enabled at the Distribution level. To open a profile dialog, click the Browse button.


Once you have set a profile, you can enable "Shared Bandwidth with Server" by placing a checkmark next it or leave it disabled.

  • If the “Shared Bandwidth per Server” option is checked, all virtual users in the same distribution will share bandwidth. This option will emulate some real world scenarios; for instance, if all users in a small office shared bandwidth to connect to the Internet.
  • If the “Shared Bandwidth per Server” is unchecked, bandwidth will be allocated to each virtual user.


Check out The Performance Beacon, our SOASTA blog, to read about more SOASTA 57 features.

Test Results

VIew performance statistics in the Dashboard widgets with Split by filters. For instance, on the Load Test Summary Dashboard, click the Average Response Time widget setting icon and choose Split or Combined by Dimension.

Next, choose Split by Network Emulation Profile.

Now, the widget title changes from Average Response Time to Average Response Time by Network Emulation Profile. Click the Legend triangle icon and you will see a color scheme of network emulation profiles.

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