Two functions of bridging are connecting distinct networks at the data link layer and expanding the physical size of a network.
Bridging plays a crucial role in networking by facilitating communication between different network segments and extending network reach. Based on the provided reference, we can identify key functions that bridges perform.
Connecting Networks at the Data Link Layer
One primary function of a bridge is to connect and enable communication between two distinct networks at the data link layer. In the OSI model, this means bridges operate at Layer 2. They read the MAC addresses in data frames and decide whether to forward frames between the connected network segments. This selective forwarding helps isolate traffic, improving network performance by reducing collisions within segments.
Consider two separate local area networks (LANs). A bridge can be used to connect these two LANs, allowing devices on one network to communicate with devices on the other. The bridge intelligently forwards data only when necessary, preventing unnecessary traffic from flooding all connected segments.
Expanding the Physical Size of a Network
Another important function of bridging is to expand the physical size of a network. While technologies like repeaters also expand the physical size, bridges do so more intelligently by segmenting the network. By connecting multiple network segments, a bridge effectively increases the total area covered by the network and the number of devices that can be connected.
For instance, Ethernet networks have limitations on the maximum cable length and the number of devices in a single segment due to signal degradation and collision domains. A bridge can connect two or more such segments, allowing the overall network to cover a larger physical area and support more devices than a single segment could.
Additional Connectivity Use Case
The reference also mentions that bridges can be used to:
- Connect a LAN segment to another LAN segment in another location via a synchronous modem connection.
This highlights the flexibility of bridges in connecting segments over different media types or distances, further enabling network expansion and inter-connectivity.
Here's a summary of the functions discussed:
| Function | Description | Layer (OSI) |
|---|---|---|
| Connecting Networks | Enables communication between distinct networks | Data Link (Layer 2) |
| Expanding Network Size | Increases the physical coverage and device capacity of a network | N/A |
| Remote Segment Connection | Links LAN segments in different locations via modem connections | N/A |
In summary, bridges are essential networking devices for segmenting networks, improving performance through intelligent forwarding, and expanding network reach by connecting multiple segments.
