Level 2: Rookie

Modem Displayed speeds vs Actual speeds

So the displayed download/upload speed shown when you log into your respective router are they meant to be real time and taken literal? 

I just want to double check an confirm because to my knowledge apparently you loose packets or something like that and you don't actually receive the speed you think you are, which is fine mines not too bad for a FTTN but I'm obviously paying a premium of $129/monthly for my service & there are other factors I have also picked up very minor though.


So firstly I do remember my gateway orignally displaying a DS speed of 88/89+ which has permanently dropped a few bits, anyone know any factors here? 


Secondly my actual speed is this: (ignore the ping)

The main thing I want to know is it normal to have a 9-11 megabit loss for the DS speed? (Our internet is so **bleep** in Australia especially for the price we pay & that "loss" is bascially a megabyte+ & I feel as if we gotta scrape everything we can lol) Theoretically if I upscaled my US speed to the same as my DS it would presumably be only half the bits (4-6) in packet loss, (not sure if it is "packet loss" or what the correct terminology is.) 


Lastly I will note I understand the basics of speed testing, running mutiple tests, using correct/different servers to check, having only 1 device plugged in via ethernet, no other devices connected/wifi turned off, updated software, power cycling, etc... I did also do the telstra troubleshooting which came up fine with no issues I kinda thought telstra were short changing me those 10 or so bits.


I do understand this is problably very minor if not at all even an issue I just want to educate myself as its kinda been in the back of my head for awhile but I'd also love to hear what type of connection other people are using, costs & whats displayed on your router/plan speed vs actual speed you recieve?


To summerize my own, Telstra $99 plan with added $30 speed boost on a FTTN connection, my speeds displayed in the second picture are very accurate as to what I actually recieve. (of course ignore the ping it's problably the most unrealistic number I've seen in my life.)


Thanks for your time, Have a wondeful day.

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Level 25: The Singularity
Level 25: The Singularity

Re: Modem Displayed speeds vs Actual speeds

The speed shown is the speed of the link. The speed you get when you do a speed test is always a few megabits lower due to the overheads bits in the packets. Each packet on a DSL link contains error correction and detection bits as well as the data. The actual speed will also be reduced if you have a bad connection and have a lot of CRC errors. A CRC error occurrs when a received packet is so corrupted it can not be fixed by the error correction bits in the data.


You can check the number CRC errors on the Sagemcom F@st5355 by logging into the gateway and going to Advanced > Gateway Settings > Device Info > Statistics > WAN Layer 1 - xDSL


Telstra is not short changing it looks like the Maximum speed of your link is 86.8 Mbps due to distance from the Node. On a link capable of the full 100 Mbps the DSL download speed is probably 114 Mbps instead of 100 Mbps to account for the overheads in each packet. You can check your link status in in the Gateway by going to Advanced > Gateway Settings > Dev Info > General > xDSL (Near bottom of page)  Below is an example of a 25/5 FTTN link, the DSL line speed is 28/6.4 to account for the overhead extra bits in each data packet.


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