We are using ERP applications where application serve is at one location and database server at different location. both locations are connected through a 2 MBPS MPLS link ( latency 4-5 ms). problem is that sometimes i can login to the application and sometimes i get TNS packet writer failure error, this happens particularly when we try with a user id which is having more roles (heavy profile). other application like RDP or web applications work fine over the same link. when i try to login into the application from data centre itself there is no problem i can login with any user ID. please suggest some solution.

Software/Hardware used:
oracle 10g