Broadband is shred connection, so whatever the speed that the customer is promised to get- it depends on the network performance and how many other users are sharing the same cable. so you keep fighting for the speed all the time. so you are getting the internet from a shared large pool of customers.
even with business broadband, the speed at the peak time is seriously affected by the number of users who's sharing the same cable which means some time the speed decreased to less than 10% of the promised speed - this why the ISPs always include some informations in there announcements about average speed.
upload speed is very limited in broadband service, and most cases it will not exceed 10% of the download speed. so if you are getting 100 Mbps download then the average download speed will be in the range of 10 Mbps
Dedicated Business Line
But with the dedicated internet leased line, theres no sharing with others. always you have to get the full speed agreed on in the contract. so if its 1 Gbps- that is mean all the time 24/7/365 you have to get 1000 Mbps.
Dedicated Fibre leased always comes with a guaranteed SLA, so the service provider shall make sure to guarantee the availability he promised, otherwise he has to compensate the customer for the disconnection times.
with dedicated internet leased line, theres no contention ratio which is for broadband customers could reach 40:1.
But with the dedicated internet leased line, always the ration is 1:1 without any sharing.
Upload Speed in dedicated business internet leased line always the same “ SYMMETRICAL” which means : if the download speed = 1,000 Mbps then the upload speed will be the same = 1,000 Mbps