No SNMP connection to the end host. Set up the SNMP connection to the end host. Make sure all device requirements are met. Check to see if the device where the LEC resides is SNMP reachable. No connectivity between clients.
Clients belong to different ELANs.
One client is unknown to the other. BUS performance graph indicates high usage. Client using maximum amount of bandwidth. Determine which LEC is generating heavy broadcast usage. Unexpected volume of control frames.