Network crashing when large file sync

I’m hoping you guys can help me out with this issue. It will become an even larger issue as we continue to grow, we should have 3-5 more employees in the next 2 months that will add to our network issues.

We use Seafile as a local cloud solution. We are essentially an engineering firm that creates and uses quite large files, this is why we chose Seafile to store files on our local machine and sync with the server. Our issue now is that with 15 employees almost all using it with large files, our network bogs down and essentially crashes time to time due to SeaFile syncing.

I don’t have exact details on me about our network, but we use a 48 port Cisco switch. I’m 98% sure its 1gig but it is probably 4 years old as is our Cisco router. I would think if any network hardware the issue would be from either the switch or less than cat5e cabling. This is a newish building so all wires should be cat5e.

Please point me to what I can look into to fix this issue before it becomes a bigger issue. Thanks in advance

You can ask the users to limit their bandwidth usage in the client settings.

What does “crashing” mean in detail?