Though there are roughly 200 ISPs in Australia the retail broadband market is dominated in Australia by a small number of firms. Telstra provides nearly 45% of services and has roughly four times as many retail subscribers as the second largest player Optus with around 11% of the market. iiNet and TPG and Primus are other major players and each has around a 5% share. The remaining 30% of the market is shared between around 180 small and medium sized providers. Consolidation in the retail ISP market has occurred with a number of mergers in the last two years. The most notable of these deals was between iiNet and Westnet and between TPG, Soul and Chariot Internet. Of critical importance to ISPs is whether to further invest in DSLAM infrastructure as the fibre optic based national broadband network is built. Further investment will enable ISPs to directly connect subscribers to their network rather than relying on purchasing wholesale services. However in the longer term the NBN may render this investment obsolete as subscribers are migrated to the fibre network.