Why Is My 1 Gb Really 100mb?

 

I’ve seen various themes on the same scenario multiple times;

-          Client upgrades network components and sees no improvement, or gets worse performance and has no idea why.

-          Could be a new access point, new switch, router, firewall, internet package or client computer

There are multiple issues with this scenario that I can highlight with a few questions

-          Do you know what the performance was before?

-          How did you test?

-          Did you monitor?

-          How long did you test for?

-          Was there any business or social events that would impact performance like tax season for an accounting department or Christmas season for a department store?

Let take a simple scenario where the analyst upgraded the internet bandwidth from 100 Mb/s to 1 Gb/s. He performed a simple speedtest from speedtest.net before and after the upgrade, from the same computer, at the same time, multiple times.

Before the upgrade, the analyst recorded an average of 93 Mb/s upload and download.  After the upgrade the numbers were identical. He immediately checked his computer nic speed, which was 1 Gb/FD and same for his switch port.

Spoiler alert:  in this case there was a cable between the firewall and switch that was running at 100 Mbs since the cable was ‘marginal’ at best.

I replicated this scenario in my lab and created this video for your enjoyment and entertainment.

Enjoy