Dirsync urgent issue

Hi all experts,

I met an weird issue when I tried to sync up my local directory to Windows AZURE/O365. There are more than 30,000 objects in AD and I use Dirsync to synchronize by OU. However, the connection between Azure and Dirsync server disconnected frequently(1 time per hour or more) and service stopped.Besides the network issue, is there any other possible reason?

Thanks indeed an wating for your answer.