Image Credit: TURK, Inc.
Network gateways are used to interconnect networks, including those with different communications protocols. They serve as the point of entry to a network and operate at various network layers. Gateway servers are hardware devices and gateway nodes are associated with routers and switches.
How Network Gateways Work
The way a gateway works depends upon its type. For example, gateway servers are often equipped with multiple network interface cards (NICs) - one for incoming traffic and one for outgoing communications. At the enterprise level, gateway nodes may be routers that use headers and forwarding tables to determine where data packets are sent. The other part of these gateways, the network switch, determines the path that the packet follows.
This diagram depicts a gateway server used by four networked computers. In this example, the gateway server also functions as a firewall.
Image Credit: HowtoForge
Types of Network Gateways
The GlobalSpec SpecSearch database provides information about many different network gateways, including the following types.
- Default gateways are computers used to access external networks when another gateway is not specified.
- Media gateways are used with audio and video transmissions.
- Payment gateways are secure computers that receive and then accept or decline on-line payments.
- VoIP gateways are used with voice over Internet protocol (VoIP) communications such as phone calls made from PCs.
Wireless or WAP network gateways are also available.
Product and Performance Specifications
Performance specifications to consider when searching for network gateways include the number and type of ports, the total number of users, and the maximum data rate.
Features and Applications
Gateway servers are often stackable or rack-mounted for use in computer rooms. These devices may include LED indicators for monitoring purposes. Other features for gateways include integrated firewalls for security and support for tunneling, a technique where packets are transmitted across a public routed network in a private "tunnel" that simulates a point-to-point connection and allows network protocols to traverse incompatible infrastructures.
Related Products & Services
Network equipment is used to split, switch, boost, or direct packets of information along a network. This product area includes network hubs, switches, routers, bridges, gateways, multiplexers, transceivers and firewalls. In addition to device type, network equipment is defined by protocol (e.g., Ethernet).
Network firewalls protect computer networks against unauthorized use or attack. They permit or deny access to private network devices and applications, and represent an important part of an organization's overall security policy. Firewalls may be software applications, hardware devices (such as routers), or a combination of both. They include turnkey products that are relatively easy to install as well as complex, multi-layer installations that require the expertise of a certified network administrator.
Network hubs provide a central location for attaching wires to workstations. Often, these hardware devices include a network switch that controls how and where data is forwarded.
Network Repeaters and Extenders
Networking repeaters regenerate incoming electrical, wireless, or optical signals to preserve signal integrity and extend the distance over which data can travel. They are often used to connect cable segments in IEEE 802.3 networks.
Network routers are protocol-dependent devices that connect subnetworks, or that break down a large network into smaller subnetworks.
Network switches connect network devices to host computers and allow a large number of devices to share a limited number of ports. They increase network capacity and speed by examining and filtering data packets. Switches also regenerate forwarded packets, reducing collision rates and permitting the use of additional nodes.
VoIP and IP Telephony
VoIP and IP telephony allows PC users to make phone calls over the Internet or other packet networks via gateways and standard telephones.