Did you notice your Mac suddenly using upload and download bandwidth and you aren’t sure where it is coming from? If you opened Activity Monitor and sorted for process name of nsurlsessionid then sorted by received packets, you might see this process hogging your Internet bandwidth.
Note: ensure you have enabled all processes in Activity Monitor. View -> All Processes.
nsurlsessiond is associated with iCloud Drive. If you have iCloud Drive disabled already (System Preferences -> iCloud -> iCloud Drive) there might be a 3rd party application trying to use it.
1. Open Terminal. (Hard Drive -> Applications -> Utilities -> Terminal)
2. To see your Mac’s current network connections in real time, type:
netop -m tcp
This nettop command filters for TCP connections. TCP connections are what most Mac OS X applications use to communicate over a network so this is what we are concerned with.
Drag your terminal window out to see bytes in and bytes out columns. Any new network connection for a process your Mac sends or receives will list at the bottom of the window and current connections will update in real-time.
So as long as the nsurlsessiond process continues to communicate and use network bandwidth, you will see that activity in your Terminal window. Most likely, you will notice the activity coming from
come.apple.iClou.XXX. You will see the associated network hosts outgoing as well.
To quit nettop, use
z key combination.