Hundreds of members of the Rail Maritime and Transport (RMT) union based in south Wales and the Marches are to walk out from 14 to 19 December.
The workers are to strike in protest at the "imposition" of rosters at a control centre due to open in January, reports the BBC.
The staff involved, who voted two-to-one in favour of strike action, are based in Cardiff, Newport, Port Talbot, Vale of Glamorgan and the Rhymney Valley. Network Rail said that contingency plans were in place, and that there would be minimal disruption to services.
RMT general secretary Bob Crow said: "Our members are furious at the attempts to bulldoze through rosters. RMT maintains that the existing 12-hour roster is tried and tested, and that the eight-hour roster will have damaging consequences."
Both Network Rail and the RMT have said they are available to negotiate a settlement.