Hi Natalia,
Thanks a lot. Actually our problem is resolved now. We have implemented the same suggestions, but from many similar other forum where you provided these solution.
Just to mention the solution, as it might be helpful to others, we followed the below procedure.
The password for SAPNDL (Standard SAP database user of live cache) was in capital letters in live cache database, so was maintained in the integration data in LC10. We changed the password, keeping it same in small letters and again tried the connection test in DB59 and was successfully connected. Thus the upgrade also completed successfully.
On thing still remains a mystery that we did not changed password in LC10 integration data, but it worked. Is their any case sensitivity issue in this configuration.
Thanks & regards,
Saravanan Nadar.