What is a network gateway
A gateway converts packet headers, routes traffic between network segments, and serves as an entry-exit point for devices and applications. In modern IT infrastructure, gateways are used to connect local networks, integrate segments (LAN, WAN, the Internet), and create secure perimeters.
In a typical scenario, a gateway is a router or server with additional logic: NAT, DPI, security policies, VPN, and address translation.
Features and functions
A modern network gateway combines several traffic processing mechanisms at once:
- Protocol conversion (for example, between Ethernet and MPLS, IPv4 and IPv6).
- Routing and access management.
- NAT/PNAT (address translation).
- Implementation of firewalling and access segmentation.
- Connecting external services and backup channels.
A network gateway can be either hardware — a dedicated router or security gateway — or a software component. For example, virtual gateways in DPI systems or on the OpenStack platform are often used for flexible routing and traffic filtering.
Types of network gateways
| Type | Application example | Description |
| Router | Company internet gateway | Main gateway between the network and the provider |
| Hardware gateway | UTM, Cisco ASA | Traffic filtering, VPN, security |
| Software | NGINX, Linux bastion | L7 proxy, load balancing, conversion |
| Virtual (vGW) | OpenStack, VAS Experts DPI | Multi-service operators and clouds |
Usage example
When connecting an office network to the internet, the role of gateway is performed by a router — it receives the external IP address and assigns internal devices addresses from the local range, providing translation and filtering. In mobile network architecture, gateways such as PGW and GGSN define the boundary between the operator’s network and the outside world.
For telecom operators and large companies, integrating gateways with DPI improves the efficiency of traffic filtering, SLA guarantees, and QoS control.
Network gateway vs. router — what’s the difference?
These terms are often used as synonyms, but they refer to different things.
| Router | Network gateway |
| Forwards packets between IP networks | Provides interoperability between different networks and services |
| Operates mainly at the network layer | Can operate at multiple layers of the OSI model at once |
| Main task — selecting a route | In addition to routing, performs NAT, VPN, filtering, protocol conversion, and other functions |
In many modern devices, the functions of a router and a gateway are combined, so a single network node simultaneously provides internet connectivity, network protection, and traffic management. This approach is widely used both in corporate infrastructure and in carrier-grade solutions.
Technical FAQ
How does a network gateway differ from a router?
A router is designed to forward packets between IP networks, selecting the optimal route based on a routing table. A network gateway performs a broader set of tasks:
- routing
- protocol conversion
- performing NAT
- traffic filtering
- establishing a VPN connection
- access control and enabling interoperability between networks with different architectures
In many modern devices, the functions of a router and a gateway are combined.
Where is a network gateway used?
Network gateways are used in home, corporate, and carrier networks. They provide connectivity between local networks and the internet, connect branch offices via VPN, protect internal infrastructure through firewalling, and are also used in cloud platforms, data centers, and mobile networks.
In telecom infrastructure, gateways help manage subscriber traffic, apply access policies, and integrate various network services.
What security functions does a network gateway perform?
A modern network gateway is often the first line of network defense. It can perform network address translation (NAT), filter traffic according to security rules, organize VPNs, segment the network, control user and application access, and detect and block unwanted traffic.
In carrier and corporate infrastructures, gateways often work together with DPI systems, which makes it possible to analyze traffic at the application level and apply more flexible security policies.
