What is the real bandwidth that Airport can handle in the local network (wired and Wi-Fi)?

The LAN ports can handle up to 1Gbps, whereas 802.11ac WI-FI on the 5Ghz frequency can handle up to 1300Mbps (1.3Gbps). This is if the devices are compatible or whether the speed can be delivered by the Internet Service Provider. 802.11b/g/n handle less speed than this.