Workers in the CWU union at the emergency services telecoms network company, Airwave, struck on Friday of last week and Monday of this week.
Workers voted for strike action to protest at planned compulsory redundancies at the company.
The action involved around 180 workers.
Airwave is owned by the Australian private equity firm Macquarie.
It wants to cut 10 percent of the workforce and freeze wages until September.
An ongoing overtime ban started on Friday 13 March.