customer is a bank main site hists the CUCM and there are 4 Branches.
All of the Branches when calling the Main site have no issues.
All of the branches have problems when calling the other branches.
Internal calls come across the GRE tunnel. So what happening is the branches are having one way call issues and drops.
QOS has been implemented along with bandwidth control via the locations in CUCM.
What else should I be looking for to correct the issues.