B757-200
Dispatch Dispatcher
Deviation / Discrepancy - Procedural Other / Unknown
Equipment / Tooling
After departure; flight crew sent me an ACARS message: 'call me 7700'I attempted a phone patch; the phone rang several times; but then disconnected. I dialed the frequency again and was successful in contacting the crew. Crew reported EICAS message: 'Right engine fuel filter'; and flight manual required landing at nearest suitable airport.  Flight returned to [the departure airport]. Reason for this report is I should not need to dial twice to make contact with crew via radio. Either the phone system is still not working properly (most likely) or Commercial Radio frequency is not reliable. I should not have to worry about phone reliability during an emergency.
Dispatcher was unable on first attempt to contact flight crew that was experiencing an emergency.