Network Bridge: Advantages and Disadvantages

Introduction : A network bridge is a networking device that uses a bridge table (also known as a forwarding database) to transmit frames across different network segments. Unlike a hub, which simply broadcasts traffic, a bridge selectively broadcasts traffic from one network segment to another and manages that traffic intelligently. It operates at the data link layer (layer 2) of the OSI model.

Figure 1: Network bridge connecting two different LAN segments.

Advantages of Network Bridges

Following are some of the benefits of network bridges.

1. Extension of Physical Network: Bridges allow you to extend the physical reach of your network.
2. Reduced Network Traffic: By segmenting the network, bridges help reduce overall network traffic.
3. Separate Collision Domains: Bridges create separate collision domains, isolating traffic and preventing collisions from propagating across the entire network.
4. Increased Bandwidth: Because bridges create separate collision domains, individual nodes have more available bandwidth since fewer nodes share a collision domain.
5. Reduced Collisions: By isolating traffic, bridges inherently reduce the number of collisions on the network.
6. Interconnection of Different Architectures: Some bridges can connect networks with different architectures and media types, providing interoperability.

Disadvantages of Network Bridges

Following are some of the drawbacks of network bridges.

1. Slower Than Repeaters: Due to the filtering process, bridges are generally slower than repeaters. Repeaters simply amplify the signal; bridges analyze the traffic before forwarding it.
2. Broadcasts Not Filtered: Bridges do not filter broadcast traffic. Broadcasts are still forwarded across all connected segments.
3. More Expensive Than Repeaters: Bridges are typically more expensive than repeaters due to their increased complexity and functionality.

Conclusion: Network bridges play a crucial role in connecting and segmenting networks, offering benefits like reduced network traffic, improved performance and enhanced security through traffic filtering. They are effective in expanding networks and maintaining data integrity between segments. However, they also have drawbacks, including potential latency, higher cost compared to simpler devices like hubs and limitations in handling modern, complex networking needs. Overall, network bridges are useful in specific scenarios, especially in small to medium sized networks, but may not be ideal for large scale or high speed environments.