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Velocity - Velocity Agent Configuration

  • Velocity 6.x - 8.x





Hardware VM hosting Velocity Agent minimum requirements:

  • Virtual CPUs 6
  • Memory 8GB
  • Disk 100GB

NTP settings

Ensure that you configure the system clock on your Velocity instance and the host on which the Agent is installed to be in sync and set to use the same NTP server to ensure that it keeps the correct time.
 If the Velocity VM and the Agent host are not in sync, the Agent may stop extending a reservation and execution may be aborted.

Operative System support

  • Windows 10 Pro
  • Windows Server 2019 64 bit
  • Red Hat Linux 7.6
  • Ubuntu 18.04 LTS
Any other Linux or Windows operative system are not certified by our Q&A team, which means that systems out of the list may not work or behave as expected.

Agent software Download and Installation

Spirent Customer Service Center > Procut Line Filter [iTest/Velocity] > Velocity Agent Installer, v8.3.0 for <Agent VM OS>.

The agent version and the velocity server version should always match in the first 2 levels of the version.
Velocity agent 8.1.0  == Velocity Server 8.1.0. Matching combination, it will work!
Velocity agent 8.2.0  == Velocity Server 8.3.0. This combination will not work!

For windows:

  1. Unzip file:
The file by default Velocity agent files are extracted to the following location:
You may unzip the Velocity Agent to any location (to extract velocity-agent into a path
with a shorter character count, for ease of reference and usage).
  1. View the setup-agent-service.bat file for additional information regarding the
available options such as Agent process count.
(located in the root directory of the Velocity Agent installation)
**Do not forget to point the velocity host to your velocity IP or FQDN.
  1. Edit the file \velocity-agent\setup-agent-service.bat and customize the variables to match your requirements.
  1. Run this file as an administrator.
The agent will start automatically at the next reboot of the Windows machine.
To launch it manually without restarting the system, use the Windows Services application:
locate the velocity-agent in the list of services and click Start the service.

The log file agent.log is located in the folder named logs within the Velocity Agent
extraction folder: \log\agent.log
**Any change desired on windows over the velocity IP or process count will require an agent service removal and to run again the setup-agent-service.bat to apply any change.

Windows Service removal:

  1. Open a CMD console as administrator and get into the installation/extracted folder.
  2. Locate the nssm.exe executable.
  3. Run the command "nssm.exe remove <service name>", you will be prompted for a confirmation.

nssm.exe remove "velocity-agent"

For Linux:

  1. Run the self-executable file: .
  2. The Velocity Agent installer prompts you to confirm whether you wish to install Velocity
  3. Agent as a daemon.
  4. Type “yes” to install as daemon.
Configure the Velocity instance.
Edit the file according to your installation:
View the agent.conf file (located in /etc/opt/spirent/velocity-agent/agent.conf)
**Do not forget to point the velocity host to your velocity IP or FQDN.
  1. Command: sudo /etc/init.d/velocity-agent start  “ [or stop] will start [or stop] the agent.”

The logs on linux installations can be found at: /var/opt/spirent/velocity-agent/log/agent.log


Each process on the agent will consume one Agent license entitlement from the velocity server targeted in agent.conf file for linux and setup-agent-service.bat for windows.

Agent process escalation procedure:

In case that you have the need of increasing the process count after acquiring new licenses, do not forget to increase the VM cores count from 6 to match any process number greater than 6 on the VM hosting the agent.

  • 8 Agent process running == 8 cores assigned to the VM.
  • 8 Agent process running == (2 GB of ram per process) 16 GB of ram in total assigned to the VM.

Configure Velocity Agent dedicated pools and restrictions 

Velocity Agents pools and restrictions provide these functions only:
  • “startupteardown” to perform startup, teardown tasks,
  • “triggered” to perform event driven task,
  • “driver” to perform driver tasks,
  • “slc” to perform interactive terminal sessions, and
  • “real-time” to perform real-time monitoring tasks.
This can be configured in the file under configuration/restrictions.ini on the installation/extraction directory of the agent.
**For windows a removal of the service and run of the setup-agent-service.bat is required to apply the changes.

For any advance configuration or more detailed information about Agents deploying and configurations please refer to the latest Velocity 8.3.0_Agent_UserGuide.

You can find this documentation at the download site under Velocity Agent Documentation located at:



FindMe. Velocity - velocity agent - agent - configuration - agent OS support - agent crash - agent configuration - process count

Product : Velocity