The Cisco 819 ISRs provide Internet, VPN, data, and backup capability to corporate teleworkers and remote and small offices of fewer than 20 users. These routers are capable of bridging and multiprotocol routing between LAN and WAN ports and provide advanced features such as antivirus protection. The Cisco 819 ISRs are fixed-configuration data routers that provide four 10/100 Fast Ethernet (FE), 1 Gigabit Ethernet (GE), and WAN connections over Serial and Cellular (3G) interface. The Cisco 819HGW and Cisco 819HWD ISRs support WiFi radios (AP802H-AGN). A Wireless Local Area Network (WLAN) implements a flexible data communication system frequently augmenting rather than replacing a wired LAN within a building or campus. WLANs use radio frequency to transmit and receive data over the air, minimizing the need for wired connections. The Cisco 819HG-4G and Cisco 819G-4G support multimode 4G LTE and have embedded Sierra Wireless multimode modem.