5,000 homes and businesses in Cavan are now connected to the NBI network.
Almost 14,200 premises across the county can order or pre-order fibre broadband.
The rollout forms part of the National Broadband Plan, which includes 17,000 Cavan premises in the State's Intervention Area.
The project represents €65 million in Government investment, delivering minimum speeds of 500 Mbps to rural communities including Bailieborough and Killashandra.
NBI spokesperson, Sandra Dinan says great progress is being made in Cavan.