Best thing to do here is find out from Server Team which lun is affected, check for errors on the host,  What do they mean by disconnected?, is it going write disabled, or is it loosing a path?  Is there only one device affected or is it muliple?,  Does the symptom occur at a specific time?  An EMC grab should be gathered and run through ELAB advisor, you may want to open up a case with support with a clear problem description, we'll be more than happy to have a look
Server team is mentioning that they had several disconnects to storage on a server. Lun keeps being disconnected. 
Devices are being disconnected