The BT Smart Hub (formerly BT Home Hub) is a family of wireless residential gateway router modems distributed by BT for use with their own products and services and those of wholesale resellers (i.e. LLUs) but not with other Internet services. Since v 5 Home/Smart Hubs support the faster Wi-Fi 802.11ac standard, in addition to the 802.11b/g/n standards. All models of the Home Hub prior to Home Hub 3 support VoIP Internet telephony via BT's Broadband Talk service, and are compatible with DECT telephone handsets. Since the Home Hub 4, all models have been dual band (i.e. both 2.4 GHz and 5 GHz).