Problems with choppy live video

[user_678151289221293_678151289221293]

I'm having a problem in that some of my cameras provide a steady live stream, and others are very choppy and constantly "hang." I have two full systems (DVR with multiple cameras) one and separate camera not connected to a DVR. One of the full systems (which is at a second home) and the separate camera all have very choppy live video when watching over the iPhone app or iMac desktop app. The other full system has a constant, steady video stream when watching over the iPhone app or the iMac desktop app.

Interesting Data:

One of the full systems that runs well AND the single POE E1 Outdoor Camera are in the same house, on the same Internet system. The full system runs fine. The single camera runs fine on the iPhone app but is very choppy over the iMac app.

The full system at the other house runs choppy and skips on both the iPhone app and the iMac app.

Anyone have any clues as to how to have them ALL run smooth when watching live video?