Page 8 - EngineerIT June July 2025
P. 8

CONNECTIVITY



























        Speed tests and the missing Mbps:



        why can’t you hit the 1Gpbs mark?





            ong-time internet users may recall the good old days of dial-up internet   The same applies to wireless
            connections and the anticipation of a noticeable improvement in experience   services, where, for example, even
        Levery time the line speeds were upgraded. Fast forward to today, and     though 5G may be capable of a
        customers don’t seem to feel the same difference when upgrading – so, why is   theoretical speed of 20Gbps, this is
        that the case? This is where it becomes necessary to understand the differences   based on using the best equipment
        between capacity and throughput, and evolving connectivity requirements at   in ideal conditions, and even then
        home and the workplace.                                                   there are radio frequency limitations
                                                                                  that will prevent this speed from
        A favourite thing for people to do when they get an internet connection for the   being reached in real world use
        first time, or upgrade, is to run a speed test. But, something strange happens: a   cases.
        customer with a 500 Mbps connection might download a file from a fast server
        and achieve 480 Mbps; when they upgrade to 1 Gbps, they might expect to see   ISPs also make use of contention,
        960 Mbps, but instead, they only get 600 Mbps.                            which segregate different service
                                                                                  profiles. A dedicated service
        External factors impacting performance                                    will have much less contention
        Why? At lower speeds, the internet connection itself is the bottleneck – meaning   than a broadband service.
        that you can get close to the plan's advertised speed. But, beyond certain speeds   Higher-contended products
        the bottleneck is no longer your access speed, but external factors such as   allow customers to use their full
        servers, end-to-end network conditions, and even the TCP/IP protocol itself.   connection simultaneously, and
                                                                                  as such the customers share a
        So, even if you have a 1Gbps, 10Gbps, or 100Gbps connection, if the maximum   portion of the network's capacity. In
        throughput achievable due to server-side or network limitations is 600Mbps,   such instances, users may observe
        that is all you will get. In this example, the capacity – the maximum data rate   higher throughput at off-peak times,
                                      under ideal conditions – is 1Gbps while the   and lower throughput during peak
                                       throughput – the actual data rate achieved   times when more users are active.
                                        in the real world – is 600Mbps. As fibre   Similarly, with wireless services, the
                                        internet access line capacities continue   more people connect to a single
                                        to increase, these limitations will become   tower, the lower the throughput
                                           more noticeable.                       becomes.



                                                By Theo van Zyl (left), Head of Wireless at Vox, and Andre Eksteen (right)
                                                Senior Product Manager of FTTB at Vox



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