Speedtest is a browser-based throughput test or quality test between an end-user connection and a well-defined endpoint in your network – that is, a Netrounds Test Agent.
The main differences between Netrounds' Speedtest and publicly available tools such as bredbandskollen.se or speedtest.net lie in where the servers are located and what you can do in addition to a Speedtest in order to spot and locate problems. One main advantage with Speedtest is that your customers can measure broadband speed in a controlled environment. This is illustrated in the picture below:
Another benefit of Netrounds' Speedtest function is that it supports additional and more advanced testing and troubleshooting features, suitable for use if the Speedtest indicates a network performance issue.
To start using the Netrounds Speedtest, you need to enable it on at least one of the Test Agents that you have registered to your account. You find your Test Agents under Test Agents in the main menu. How to enable Speedtest is described on this page.
To run a Speedtest in your favorite web browser, click the button Go to public page. You are now invited to choose whether you want to run the application using Adobe Flash or WebSocket. WebSocket makes it possible to run Speedtest from mobile devices or other browsers that do not have Flash installed. Please note that the WebSocket Speedtest is currently a beta version.
On clicking one of the buttons, you are taken to the public Speedtest page. Its URL differs depending on the technology chosen:
- Flash: https://app.netrounds.com/<netrounds_account_name>/speedtest.
- WebSocket: http://app.netrounds.com/<netrounds_account_name>/speedtest-websocket.
Click the Start button on this page to start a Speedtest.
These are the steps performed during a Speedtest:
- Download: A number of parallel TCP sessions (by default, 8 are set up to measure the receiving capacity towards your computer.
- Upload: A number of parallel TCP sessions (by default, 8) are set up to measure the sending capacity from your computer.
- TCP Ping: A small amount of data is sent back and forth over a single TCP session to measure the round-trip delay.
- ICMP Ping: ICMP echo requests are sent from the server to measure round-trip delay and loss.
The public Speedtest page displays selected metrics:
More detailed information on the outcome of the test, and other tests that have been performed towards your account, can be viewed in the Netrounds user interface. Click Apps in the main menu:
Then click the Speedtest box to go to the Speedtest result pages:
WebSocket TCP information
With WebSocket, some TCP information is obtained which is not obtained with Flash. During WebSocket-based Speedtests (both upload and download), the tcp_info struct in the Linux kernel on the Test Agent is sampled once every second. These samples are then aggregated and reported on the Speedtest result page under Details on the TCP info tab.
- Congestion window: The congestion window is a TCP sender limitation on the number of packets allowed to be transmitted without acknowledgement. Each second the sum is taken of the congestion windows for all TCP sessions in the test. The max, min, and average presented in the results are based on these samples.
- Packets in flight: The number of transmitted packets waiting for acknowledgement from the receiver. Each second the sum is taken of the number of packets in flight for all TCP sessions in the test. The max, min, and average presented in the results are based on these samples.
- RTT: TCP round-trip time. The presented max and min values are taken over all samples obtained during the test.
- RTT variance: TCP round-trip time variance. The presented max and min values are taken over all samples obtained during the test.
- Retransmissions: Total number of retransmitted packets in all sessions during a download test.
- Path MTU: Path Maximum Transmission Unit determined in the course of the download test.
- Max active sessions: The maximum number of TCP sessions that were active concurrently during the test. A session is considered active if some data has been transmitted since the last sampling of tcp_info. Note, however, that this number is not itself found in the tcp_info struct.
For uploads, fewer measurements are obtained: RTT (max/min/avg), Path MTU, and Max active sessions. They are analogous to those obtained for the downlink; see above.