This article is about the types of network routers and modems found in many homes, known colloquially as "residential gateways".

A residential gateway is a home networking device, used as a gateway to connect devices in the home to the Internet or other WAN.

It is an umbrella term, used to cover multi-function networking computer appliances used in homes, which may combine a DSL modem or cable modem, a network switch, providing LAN switching, a consumer-grade router, and a wireless access point. In the past, such functions were provided by separate devices, but by technological convergence, they have often merged into a single device.

[edit] Term

There are multiple devices that have been described as "residential gateways" each with a different function. Each type of device allows the connection of a LAN (used in the home) to a WAN. The WAN can be often the Internet or can merely be a larger LAN of which the home is a part (such as a municipal WAN that provides connectivity to the residences within the municipality). WAN connectivity may be provided through DSL, cable modem, a broadband mobile phone network, or other connections.

The term "residential gateway" was originally used to distinguish the inexpensive networking devices designated for use in the home from similar devices used in corporate LAN environments (which generally offered a greater array of capabilities). In recent years, however, the less expensive "residential gateways" have gained many of the capabilities of corporate gateways and the distinctions are fewer. Many home LANs now are able to provide most of the functions of small corporate LANs.

Therefore the term "residential gateway" was becoming obsolete and merely implies a less expensive, lower capability networking device.

Nowadays, the home gateway tends to have abundant interfaces, powerful functions and a more user-friendly interface. It is a manageable terminal with auto-configuration, multiple interfaces, and multi-service perceiving and bearing. The home gateway provides Quality of Service to bear services of different types at the same time. As a part of the carrier network, the home gateway shall support remote control, detection and configuration.^[1]

[edit] Devices

Multiple devices have been described as "residential gateways":

• Cable modem
• DSL modem
• Network modem
• Router or Wireless router
• Network switch
• VoIP ATA
• Wireless access point

or any combination of the above.

[edit] Types

• A router provides:

• IP address routing
• network address translation (NAT)
• DHCP functions
• firewall functions
• LAN connectivity like a Network switch

Most routers are self-contained components, using internally-stored firmware. They are generally OS-independent (i.e. can be used with any operating system).

• Wireless routers perform the same functions as a router, but also allows 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.)

• A modem (e.g. DSL modem, Cable modem) provides none of the functions of a router. It merely allows Ethernet 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 USB modem plugs into a single PC and allow connection of that single PC to a WAN. If properly configured, the PC can also function as the router for a home LAN.
• An internal modem can be installed on a single PC (e.g. on a PCI card), also allowing that single PC to connect to a WAN. Again, the PC can be configured to function as a router for a home LAN.

• 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.

[edit] Features

Beyond basic connectivity and routing, residential gateways can provide addition features, such as:

• Configuration via a web interface
• Dynamic DNS

[edit] Manufacturers

There are a number of manufacturers of networking devices that have been used as residential gateways:

[edit] See also

[edit] References

[edit] External links

• Home Gateway Initiative, which proposes specifications for residential gateways
• The Residential Home Gateway on About.com
• Home Gateway–A Key to Open Digital Home (Huawei).