A residential gateway is a small consumer-grade router which provides network access between local area network (LAN) hosts to a wide area network (WAN) (like the Internet) via a modem. The modem may or may not be integrated into the hardware of the residential gateway. The WAN is a larger computer network, generally operated by an Internet service provider.
Multiple devices have been described as "residential gateways":
or certain combinations of the above.
A modem (e.g. DSL modem, Cable modem) by itself provides none of the functions of a router. It merely allows ATM or Ethernet or PPP traffic to be transmitted across telephone lines, cable wires, optical fibers, or wireless radio frequencies. On the receiving end is another modem that re-converts the transmission format back into digital data packets.
This allows network bridging using telephone, cable, optical, and radio connection methods. The modem also provides handshake protocols, so that the devices on each end of the connection are able to recognize each other. However, a modem generally provides few other network functions.
A wireless access point can function in a similar fashion to a modem. It can allow a direct connection from a home LAN to a WAN, if a wireless router or access point is present on the WAN as well.
However, many modems now incorporate the features mentioned below and thus are appropriately described as residential gateways.
A residential gateway usually provides
Most routers are self-contained components, using internally stored firmware. They are generally OS-independent, i.e., they can be accessed with any operating system.
Wireless routers perform the same functions as a router, but also allow connectivity for wireless devices with the LAN, or between the wireless router and another wireless router. (The wireless router-wireless router connection can be within the LAN or can be between the LAN and a WAN.)
Low-cost production and requirement for user friendliness makes the home routers vulnerable to network attacks, which in the past resulted in large clusters of such devices being taken over and used to launch DDoS attacks. A majority of the vulnerabilities were present in the web administration consoles of the routers, allowing unauthorised control either via default passwords, vendor backdoors, or web vulnerabilities.