Suddenly All RFC Connections Failing ECC--PI

Hi,

Suddenly all RFC connections between ECC and PI started failing in my client's server,and all interfaces are not working.

Destination Name =PI

Destination Type = H

Error = ICM_HTTP_CONNECTION_FAILED

User ID in the Destination = REMES

User ID is not locked in PIDev for the user.

Error::ICM_Http_Connection_Failed.

Pls help.

Regards,

Sri