SRDF/A -- is stuck and not copying

We started an initial copy of 18TB of our data over to our remote site 2 weeks back and all we could copy untill now is 2TB.

Now when I run the query I do not see any movement in data and it seems to get slower each day.

Can somebody give me an insight of how this works and what we could do to speed up the process on the symm.

We already have our network guys looking at this form their end also.

My question is why would we have sortof good thoughtput during some periods of time and do nothing for the rest.