Latencies

Hie everone

I have SEP 12.1.5 running in a mixed Ms Windows Environment of 80 Users spread across 7 cities in a WAN Network. There is an accounting system we use that is centrally located and all users access it. I noticed however that since i deployed it, i am experiencing latencies to the various branches. this stops when i take the SEP Server off the network. I tried altering the policies, changing the update frequencies and even leaving them to update overnight however the problem has not changed.

Any ideas.

Thank you very much.