We want to implement a centralized ERP having Oracle Database for Both Office site (i.e. A & B as illustrated in Image attached). Employee of site B can work on Site A any Day or vice versa because of regular movement.

If we keep centralized server on Site B (Because of more Employee on site B) and access the ERP through leased line in Office Site A then Major problem is the Leased line Network which disconnected sometime due to cut in fiber which takes long hours to resume the services and employee of office site A becomes Idle. They have to wait for resume the services again.
If we implement independent ERP for both Site then employee of site A unable to work on Site B due to data availability or vice versa.
Is there any solution (like Oracle Real Application Clusters) for implementing the ERP on both sites so that whenever leased Line is disconnected then Both site ERP work independently and when leased Line is active then it synchronize database automatically without human being involvement?
Kindly Suggest any Solution.