Following command allows testing upload and download speed on the Linux, without need of installing any packages.

wget -O speedtest-cli https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py;chmod +x speedtest-cli;python3 speedtest-cli;rm -f speedtest-cli
Sample output:
Retrieving speedtest.net configuration...
Retrieving speedtest.net server list...
Testing from IPOwnerName (ServerIPHere)...
Selecting best server based on latency...
Hosted by United Networks (Jacksonville, FL) [29.40 km]: 6.362 ms
Testing download speed........................................
Download: 182.10 Mbit/s
Testing upload speed............................................. .....
Upload: 1.28 Mbit/s
If you need to monitor realtime bandwidth, you can try iftop or nload