Specifications

Configuration MP.11 5054 (MP.11a) Installation and Management

System Parameters

• Mode of Operation: This drop-down menu is used to set the unit as a bridge (layer 2) or as a router (layer 3). See

Bridge and Routing Modes for more information.

Bridge and Routing Modes

Bridge Mode

A bridge is a product that connects a local area network (LAN) to another LAN that uses the same protocol (for example,

Ethernet). You can envision a bridge as being a device that decides whether a message from you to someone else is

going to the LAN in your building or to someone on the LAN in the building across the street. A bridge examines each

message on a LAN, passing those known to be within the same LAN, and forwarding those known to be on the other

interconnected LAN (or LANs).

In bridging networks, computer or node addresses have no specific relationship to location. For this reason, messages

are sent out to every address on the network and are accepted only by the intended destination node. Bridges learn

which addresses are on which network and develop a learning table so that subsequent messages can be forwarded to

the correct network.

Bridging networks are generally always interconnected LANs since broadcasting every message to all possible

destination would flood a larger network with unnecessary traffic. For this reason, router networks such as the Internet

use a scheme that assigns addresses to nodes so that a message or packet can be forwarded only in one general

direction rather than forwarded in all directions.

A bridge works at the data-link (physical) layer of a network, copying a data packet from one network to the next network

along the communications path.

The default Bridging Mode is Transparent Bridging.

This mode works if you do not use source routing in your network. If your network is configured to use source routing,

then you should use either Multi-Ring SRTB or Single-Ring SRTB mode.

In Multi-Ring SRTB mode, each unit must be configured with the Bridge number, Radio Ring number, and Token Ring

number. The Radio Ring number is unique for each Token Ring Access Point and the Bridge number is unique for each

Token Ring Access Point on the same Token Ring segment.

Alternatively, you may use the Single-Ring SRTB mode. In this mode, only the Token Ring number is required for

configuration.

Routing Mode

Routing mode can be used by customers seeking to segment their outdoor wireless network using routers instead of

keeping a transparent or bridged network. By default the unit is configured as a bridge device, which means traffic

between different outdoor locations can be seen from any point on the network.

By switching to routing mode, your network now is segmented by a layer 3 (IP) device. By using Routing mode, each

network behind the BSU and SUs can be considered a separate network with access to each controlled through routing

tables.

The use of a router on your network also blocks the retransmission of broadcast and multicast packets on your networks,

which can help to improve the performance on your outdoor network in larger installations.

The use of Routing mode requires more attention to the configuration of the unit and thorough planning of the network

topology of your outdoor network. The unit can use Routing mode in any combination of BSU and SUs. For example, you

may have the BSU in Routing mode and the SU in Bridge mode, or vice versa.

When using Routing mode, pay close attention to the configuration of the default gateway both on your unit and on your

PCs and servers. The default gateway controls where packets with unknown destinations (Internet) should be sent. Be

sure that each device is configured with the correct default gateway for the next hop router. Usually this is the next router