Stream AVI

I have a WRT1900AC router and 4TB MyCloud with a number of AVI's (large and small) stored on it.

I'm trying to stream AVI's to my iPAD (hipserv app) and have the ipad on the 5.0 GHz band.

I have been able to sort of stream very small AVI's but they are very choppy and close out.  Anything over 1/2 Gig will not open.

My question...What are some of the basic settings on the router I should look at to enable streaming of AVI's?  If you familiar with MyCloud, what settings should I be looking at there?

Thanks in advance...John