What's the biggest pain point collaborating with remote people?

Managing remote teams may become quite painful for large teams. Few days ago I asked pretty similar question in sens of "how to keep discipline on high level for remote teams". I think, discipline is a part of sense of belonging and company's culture as well. So, I suppose timetracking, shared time sheets, daily scheduled meetings together with high level of trust based on company's culture are important components of managing remote teams.