Running Big Scenarios

Since version 2.18, the ByteBlower GUI contains some new features that make it easier to run big test scenarios.
Such tests are often called "stability tests", "stab tests" or "endurance tests".
You may have gotten here after clicking on a help button in the GUI.

New Features

  • Real time metrics are now exported by the GUI so they can be processed externally.
    In another article, we explain how to use the exported metrics: Getting started with Prometheus
  • For big scenarios with more than 100 flows, the GUI will no longer store the results over time. The reports will no longer contain graphs.
    These scenarios will be marked with an exclamation mark:
  • In the Solution tab, you can see why:

    Double-clicking on the warning will open this help page.
  • If you run a big scenario, the following warning will pop up:

    Clicking on the Help button opens this page.
  • In the Project Properties, you can now even disable graphs with results over time entirely.
    Have a look under the menu File > Project Properties > Report.

    This means that you can disable results over time even for small scenarios if you like.
    When disabled, the warning icon will disappear from all big scenarios. 

What was the problem?

We added these features because we experienced that the machine running the ByteBlower GUI was sometimes not capable of storing all realtime results quickly enough.
While running a long test with lots of flows, the GUI became less responsive and some results could get lost.


If you have any questions, don't hesitate to contact us at
Thank you!

We are pleased to announce the immediate release of a new version of the ByteBlower GUI.  


Bugfix release history:

  • ByteBlower GUI version 1.8.22 (release May 14th) introduces the features and enhancements listed below. It has been superseded by several bugfix releases.
  • The changelog below contains the original 1.8.22 changes, with the bugfix release changes listed at the bottom.
  • We encourage everybody to update to the latest version!



  • Latency reporting
    • The ByteBlower GUI can now report latency measurements with nanoseconds precision. This comes with the 1.10.18 release of the ByteBlower 2100 server.
    • The latency unit and the amount of decimal numbers is configurable in the project preferences.
    • The range of the latency distribution graph is now configurable in the Preferences.
    • The default latency measurement range is now 0s->100ms instead of 0s->10s.
    • When hovering above the latency distribution graph, the amount of frames with that latency is now displayed.
    • The CSV report now also shows a latency unit column.
    • Microseconds in the latency range can now be entered as "us".
  • The columns of the CSV report are now the same ones as those in the HTML report.
  • The "Pause after DHCP" dialog now contains a checkbox to hide it.
  • The GUI now packages with and uses a bundled Java 7 JRE on Mac OS X, as was already the case on other platforms.
  • Unicast flows are now reported without displaying 100% loss.
  • Unicast destination IP addresses are now reported too.
  • The default DHCP retransmission policy is now "Fixed Timing". This makes DHCP fail quicker when there is no DHCP server.
  • Latency Distribution graphs are now bigger: 600x200px
  • After selecting a destination for a flow, the dialog now closes immediately, to reduce the number of required mouse clicks.


  • Fixed critical bug where TCP Aggregate throughput values in the report were not calculated correctly.
  • Fixed bug where TCP Aggregate duration values in the report included flows that could not be established, which may have led to negative durations in some situations.
  • Fixed bug where TCP flows that could not be established had 'finished' status (and 0 bytes sent/received) instead of timed out status.
  • Fixed a bug in the ByteBlower server where setting a growing frame size modifier could cause the server to crash in rare situations.
  • Fixed bug where deleting a Frame and selecting a Flow Template which contained that frame caused an error.
  • Fixed bug in the internal refresh algorithm of the project model, which caused some objects to display a wrong status. For example, after using the B2B Wizard, and then docking the ports, the first flow destination (incorrectly) showed an error state.
  • Fixed bug in the Throughput Wizard, when using the Increment Throughput option.
  • When an IPv6 port cannot be configured while a scenario is being initialized, it will now show up red in the report, as was the case for IPv4 ports.
  • Fixed bug where ByteBlower ports on which DHCP/SLAAC failed (and thus lacked an IP configuration), showed their old IP addresses (as previously configured in the Port View) in the report.
  • Unicast Flows are displayed again in the report.

Bugfixes 1.8.24

  • Fixed bug in the report generation that caused an error when a scenario was run with only TCP flows.
  • Resolved an issue on Ubuntu 14.04 where HTML reports could not be opened. Opening these HTML reports caused the GUI to crash sometimes.

Bugfixes 1.8.26

  • Resolved an issue on Windows where HTML reports were not opened automatically after running a scenario.

Bugfixes 1.8.28

  • Optimized scenario execution
    • If a port fails to initialize and ignore initialization errors is active, this initialization will no longer be repeated for subsequent flows in which the port participates. This ensures consistency within the scenario being executed and reduces configuration time.
    • Frame blasting receivers are now only created for unique frames within a Flow. This decreases the load on the server.
    • GUI uses a new API version (1.8.22) that improves server memory management.
  • Improved error handling for failing multi-destination flows (ignore initialization errors active).
    • Flows with a multicast or broadcast destination will now be run as soon as a single destination port can be initialized.
    • Eavesdropper ports of a flow that fail to initialize will no longer stop the flow from running.
  • Fixed issue where a latency distribution graph did not show up in some situations.

Bugfixes 1.8.30

  • Fixed bug that caused the GUI to crash on Mac OS X when executing scenarios with TCP flows.
  • The latency precision warning in the report is no longer shown when the measured values are zero, because increasing the report precision has no effect in that case.
  • Improved server memory management.

Bugfixes 1.8.32

  • Improved duplicate frame detection during scenario initialization.
  • The throughput wizard now generates frames which differ at the start of the payload instead of at the end of the payload. This allows latency and/or out-of-sequence, which overwrite the last bytes of frames, to be enabled on the throughput flows.
  • Fixed issue where error message did not show up when opening a project created with a newer version of the GUI than the one in use.
  • Fixed issue where GUI running on Mac OS X did not detect radio-button changes (in the Frame view).
  • The command-line tool (CLT) now correctly opens projects again.


ByteBlower GUI 1.8.32 is no longer available for download. Please contact our support desk of you think you need this specific version.

We are pleased to announce the immediate release of a new 1.x version of the ByteBlower GUI.

The 1.8.36 GUI is the first 1.x GUI that is aware of the new 2.x ByteBlower servers, our platform for the future. While it can detect 2.x servers, it is not compatible with them! For this purpose, please download latest GUI 2.x from our support website.

Note that a 1.x and 2.x GUI can be installed side by side without a problem, so it remains possible to work with all servers from a single client device.

We encourage everybody to update to the latest version!


  • Changed server icons in the Configuration view: blue now means online, blue with a red cross means online but unusable (e.g. incompatible version), gray with a red cross means unreachable, gray with a question mark means unknown.
  • Introduced interoperability with 2.x servers: refreshed 2.x servers are shown as incompatible servers in the configuration view. They also show their (incompatible) 2.x version.
  • Fixed crash on Mac OS X caused by the server auto-detect service. This service is now disabled for all platforms.
  • Fixed crash on Windows in the original (but recalled) 1.8.34 release. This version is no longer available.

For the changelogs of versions 1.8.22 up to 1.8.32, see the previous release article.


You can download this version of the ByteBlower GUI from these locations:

  • [[SecureDownload:ByteBlower/GUI/1.8.36/ByteBlower-GUI-windows-x86-installer.exe:Windows installer]]
  • [[SecureDownload:ByteBlower/GUI/1.8.36/ 32bit installer]]
  • [[SecureDownload:ByteBlower/GUI/1.8.36/ 64bit installer]]
  • [[SecureDownload:ByteBlower/GUI/1.8.36/ OS X installer]]

We are pleased to announce the immediate release of a new version of the ByteBlower GUI.  


New features

  • Welcome Screen
    • Appears on first start-up after installation and every time new updates have been installed.
    • Contains the changelog and links to useful resources.
  • Automatic updates
    • Connect with the ByteBlower repository to check for a new GUI version.
    • Download and install the new version when desired. It is then applied automatically.
    • Checking for updates at every launch can be enabled or disabled in the preferences. This is enabled by default.
  • HTML report with encapsulated images


  • When opening a project, you can now see where all ports have been docked in the Configuration View.
  • Docking and undocking ports is now undoable.
  • Updated bundled JRE from Java 7 Update 40 to Java 7 Update 45.
  • When opening a project, used servers that were already present in the Configuration will now be refreshed automatically.
  • Report content
    • Added a Duration column to the TCP flows table. This is the flow duration on which the Average Throughput column is based.
    • Removed the Maximum Sender Congestion Window and Max Receivers Receive Window columns from the TCP Flows table.
    • Added two new tables to the report which contain aggregate throughput information over all TCP flows on a port.
  • Report layout
    • Numeric values are now right-aligned
    • The number of decimal numbers is now the same for all values, so numeric values are properly aligned.
    • The number of decimal numbers is configurable by the user, in the project preferences.
    • A report warning is shown if a throughput value is too low for the precision of the throughput unit and number of decimals.
    • The frame rate unit ('frames/s') for frame blasting flows is now shown in the table header instead of in each field.
    • The extra VLAN bytes designation is now only shown in a column header, when one of its column values has VLAN enabled.
    • The amount of frames, displayed on the axis of latency distribution graphs now contains a thousands separator.
    • The Frame Blasting flow info table now contains one entry per flow. This means multiple destinations of a multicast flow will not result in multiple (identical) flow info entries.


  • After Docking/Undocking ByteBlower Ports the GUI will ask if you want to save the project when closing it.
  • After changing the project preferences in the Preferences window, the GUI will ask if you want to save the project when closing it.
  • Fixed bug where reports were sometimes displayed containing an error "No editor descriptor for id org.eclipse.ui.internal.emptyEditorTab" when the GUI is launched.
  • Fixed bug where the latency distribution graph of a report was not displayed correctly when multiple UDP flows had the same source and destination port.
  • Fixed bug where list of Recent Projects in the File Menu wasn't always updated correctly.
  • The Automatic Server Discovery is now started after the GUI has started up completely. This fixes race condition issues at startup time.
  • Fixed bug where multicast flows with multiple frames had double counting in the report, resulting in losses of -100%.
  • TCP throughput is now always calculated at the receiving side of the HTTP traffic. This results in a more accurate result when HTTP PUT is used.
  • Out of sequence value was sometimes calculated incorrectly for multiframe flows and multicast flows.
  • When out of sequence is enabled on a flow, it is now also enabled on its eavesdroppers.
  • Report decimal sign and thousands separator now correctly matches the user's system locale.
  • When report generation fails unexpectedly, a user-friendly error is shown instead of opening a null report.
  • The JRE is now bundled for Mac OSX as well. This fixes a hang on MAC after running a scenario.


ByteBlower GUI 1.8.20 is no longer available for download. Please contact our support desk of you think you need this specific version.

We are pleased to announce the immediate release of a new version of the ByteBlower GUI.  


  • The Initial Receive Window is now set at the receiving side. (HTTPClient when doing GET, HTTPServer when doing PUT)
  • In the Flow Template View, it was sometimes impossible to edit the wanted throughput.
  • The Throughput Wizard sometimes generated scenarios with negative frame amounts.
  • When a VLAN tag was removed from a ByteBlower Port, this was not visible in the Port View.
  • When a new ByteBlower server is added in the Configuration View, it is now automatically refreshed.
  • In the FlowTemplate View, trailing zeros in the displayed frame interval were not displayed
  • Reports from Scenarios with flows that had initialization errors are now again generated successfully.
  • Fixed typo : "Scenario will continue to run after after...".
  • Updated Eclipse platform : using the latest Kepler plugins.
  • The default Multicast address is now
  • New IPv4 ByteBlower GUI Ports, generated by wizards, now get addresses starting at, and default gateway


ByteBlower GUI 1.8.18 is no longer available for download. Please contact our support desk of you think you need this specific version.

We to help you!