What Tool or Instrument is Used to Test Internet Speeds?

There are different types of instruments and software-based solutions (apps) that can run speed test for traditional internet access services, however, dedicated hardware-based test sets are required for speeds close to and above 1 Gbps

Simplified network diagram depicting a centralized test system and handheld field testers

The actual "Internet Speed" is difficult to test, because there are infinite end-point combinations. However, people often use the term Speed Test to refer to Internet Access Speed Test, which is the maximum speed guaranteed (or best effort) by the internet service provider (ISP). This is the speed between the gateway and/or modem at the subscriber's premises (home or business) and a dedicated server vetted by the ISP, sitting right on the "edge" of the Internet cloud.

The Software/App Approach (Not Recommended)

One popular tool to check Internet Access Speed is Ookla's Speedtest.net or derivatives offered by ISPs. Residential users often download the Speedtest™ app on their phones, tablets or PCs, and it also comes built into certain streaming boxes, routers and gateways. However, they may be limited by their processors (CPUs), internal data bus or how busy they are with other tasks. Their results could vary significantly for services beyond 500 Mbit/s (or Mbps), due to several reasons:

  • Shared CPU resources (busy with multiple applications running)
  • Limited internal data bus capacity (unable to handle the traffic)
  • No physical connection capable of 1 Gbit/s or beyond (however newer routers, PCs and laptops are starting to offer options up to 10 Gbit/s, as of 2023)
  • Limited LAN/WLAN Ethernet throughput (older Wi-Fi technology, older switch/router, etc.) 

With modern multi-Gigabit services, those approaches could cause big problems. For example, using a smartphone or tablet connected to a Wi-Fi 2.4 GHz 802.11g, subscribers may not be able to measure beyond 150 Mbit/s, even if the service can deliver much more. This can create false negatives. Just by switching their computing device to 802.11n 5 GHz mode, they should get better data rates. Furthermore, switching to Wi-Fi 6/6e (802.11ax) would provide even better results, but it still may not be enough for Gigabit services. The problem is, multi-gigabit service speed test results would depend on how it is tested. Which may trigger unnecessary Quality of Service (QoS) or Experience (QoE) complaints and potential truck rolls, which subscribers may be charged for. Here are some examples of one residential Internet Access Service being "tested" (or better yet, checked) with different consumer devices and settings, using Ookla® Speedtest™ clients:

Different devices can provide different Internet speed test results!

Needless to say, not the best approach to qualify, verify or certify modern multi-gigabit Internet access services performance, since they are all limited by their local connections (Ethernet interfaces). However, it is a realistic measure of what each individual device is getting, which can be used to troubleshoot them (e.g., move it to the 5 GHz band or to a wired connection, if supported, or it may be time to reboot it, etc.). However, the main potential problem happens when subscribers take this data and start calling their service provider to complain about their Gigabit service only reaching 123 or 614 Mbit/s, or that the image from their own streaming device (connected to 2.4 GHz Wi-Fi) is not good. They could trigger expensive truck rolls or spread rumors/reviews of poor service (QoS and QoE).

The results above are from a 1 Gbit/s Internet access service and only the wired MAC and Apple TV were able to provide reasonable results. However, they would also be worthless if used to check services >1 Gbit/s, since they are limited by their LAN interfaces.

If you are a consumer (subscriber) just wanting to check Internet access speeds, and those are the only tools available to you, we recommend using a newer computing device capable of handling the target data rates (speed) and to use a physical connection (copper/UTP or fiber) to connect directly to the modem's LAN port (called the Demarcation Point) or as close to it as possible.

Dedicated Hardware (Test Set) Approach

Hardware-based instruments are the go-to tools for service providers to verify actual Internet access speeds (upstream and downstream), since they are built specifically for the task and come with dedicated test interfaces guaranteed to consistently handle 100% traffic loads (throughput) at 1, 2.5, 5, 10 Gbit/s and beyond.

These portable testers can connect to, and test against, existing centralized Ookla servers or dedicated hardware-based test heads, to measure the actual performance of residential services and assure QoE, while still presenting test results in a format subscribers can understand. V-TEST is VeEX's hardware-based version of speed test. (Refer to the V-TEST Quick Guide for more details.)

Speed test results of a 10 Gbit/s service, requires 10G capable hardware.

Test sets can also support more robust RFC6349 TCP/UDP testing against centralized iPerf servers or dedicated test heads, to evaluate the network's Internet performance for business customers, providing reports with more technical details and results. VeEX's hardware-based test client is called V-PERF and the centralized test heads are RTUs (Remote Test Unit), capable of handling more than 100 field test sets simultaneously, without any drop in performance (using up to 100GE connections at the node). V-PERF is also compatible with existing iPerf3 servers, however, users adopting this approach must be aware of their (servers') CPU-based limitations under stress.

V-PERF (RFC6349) test results for a 100GE link

Although these professional tools are not intended for residential/consumers, as they require equipment at the operators' network, technicians troubleshooting internet access issues should bring these tools when activating, validating or troubleshooting modern multi-gigabit services. Centralized remote test units (RTU) are also used at the network, to verify nodes interconnection links and serve as traffic generators for multiple field test sets.

Simplified diagram of centralized test heads (RTU) providing support for multiple tests to field testers.

iPerf (Internet Performance Working Group) is an open-source speed test and network performance measurement tool. It uses multiple TCP and UDP streams to send traffic from one host to another. It helps determine the network's maximum throughput and top bandwidth speed. It can also help optimize the TCP windows for optimal performance. iPerf is based on RFC6349.

RFC6349, from IETF, helps service providers optimize their network for transmission control protocol (TCP) traffic and maximize its performance across a broad set of applications. It stresses networks with true stateful TCP test traffic, to assess sustaining TCP performance on the current network/link configuration, using multiple streams in parallel. That is much closer to the subscribers' experience and required by service providers for QoE and SLA verification.

Y.1564 is an Ethernet Service Activation Methodology (SAM) test suite, defined by ITU-T, to be used while installing, bringing into service (activation), and troubleshooting Ethernet-based (business) services. Y.1564 serves as a comprehensive network Service Level Agreement (SLA) validation tool, ensuring that links meet their guaranteed performance, so all services carried by the network will meet their SLA objectives at their maximum committed rate.

Related Test Solutions

  • CX310 DOCSIS 3.1 Installation Tool

  • CX380C Advanced DOCSIS & Cable Plant Maintenance Test Set
  • FX120 XGS-PON Analyzer (for Multi-Gigabit Internet Access Services)
  • MTX150x Ethernet Services Installation Test Set 
  • MTX150x Lite Multi-Gigabit Internet Services Speed Test Solution
  • MTX150 Multi-service Installation & Maintenance Test Set

  • MTTplus Modular Test Platform (MTTplus-340)
  • TX300S Test Platform (TX340s, TX300-100Gx)
  • RXT-1200 Modular Test Platform (RXT-3400, RXT-6200+, RXT-6402)
  • RTU-300 Remote Test System

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