MDS 05-6399A01, Rev. F
MDS™ Master Station
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The bridge learns the clients’ locations by analyzing the source address of incoming frames from
all attached networks. For example, if a bridge sees a frame arrive on LAN port from Host A, the
bridge concludes that Host A can be reached through the segment connected to LAN port.
Through this process, the bridge builds a forwarding table (the learning process). When a frame
is received on one of the bridge's interfaces, the bridge looks up the frame's destination address
in its forwarding table. If the table contains an association between the destination address and
any of the bridge's ports aside from the one on which the frame was received, the frame is
forwarded out the indicated port. If no association is found, the frame is flooded to all ports
except the inbound port. Broadcasts and multicast also are flooded in this way.
The bridged network is addressable via the ‘bridge’ interface (a virtual interface). The interfaces
that are in the bridge are called bridged interfaces. The interfaces that are not in the bridge are
called routed interfaces. Bridging is performed between bridged interfaces. Routing is performed
between routed interfaces. The bridge interface itself is a routed interface.
In firmware versions less than 3.0.0, the SD interface is not a bridgeable interface as
there is no packet or packet-with-MAC mode support in these versions of firmware.
Configuring
For full details on configuring bridge interfaces, please see the
MDS Orbit MCR Technical
Manual (05-6632A01).
5.9 SDMS Interface
Understanding
The configuring of SD interfaces on the Master Station is performed through a virtual interface
called ‘sdms’ (SD Master Station). This virtual interface, much like a bridge interface, is
comprised of one or more sd-nic member physical interfaces. Each installed SDM Radio Module
contains a single sd-nic. All configurations applied to the virtual SDMS interface will be
propagated to all member sd-nic interfaces. This insures that all SD radio interfaces in the system
are using identical configurations so that interface fail-over is seamless.
To access the full suite of SD configuration options, select the sdms interface from the interfaces
drawer on the left-hand menu.
Understanding the use of Virtual Radio Channels (VRCs)
VRCs allow over-the-air data to be directed to specific interface ports (IP or Serial) on the radio.
Conceptually, this can be pictured as creating “pipes” for delivery of data to the desired radio
interfaces.
VRC works by associating data from a specific port (IP and Serial) with a VRC channel number
(1, 2, or 3). Each port at the receiving end then filters incoming data based on the associated
VRC number.
The Virtual Radio Channel (VRC) feature is only supported in Packet w/MAC modes. It
is not supported in Transparent or x710 mode.
To create the “pipes” that direct data to the desired ports, a route must be established using the IP
Payload Configuration Menu (or payload serial settings on the general configuration menu for
serial data). The default setting is to listen to
all
channels.) The Talk on parameter is used to
specify the VRC used for sending the data stream over the air, while the Listen to parameter
specifies the VRC(s) for incoming data.
