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TRSM Description
The Token Ring Switching Module (TRSM) is designed to add Token Ring
(TR) switching functionality to the LANplex 6000, providing the most cost
effective solution for introducing segmentation for today's Token Ring
networks, while allowing you to prepare for future higher bandwidth
requirements such as multimedia applications.
The TRSM has eight shielded RJ-45 token ring ports on the front of the
module and one FDDI backplane attachment which may be connected to
any of the three LANplex chassis FDDI backplanes. All eight token ring
switch ports support a full ring of 260 stations, with two of the ports able to
accommodate direct station attachment for dedicated bandwidth to file
servers and other critical resources. The shielded RJ-45 ports allow for
attachment via Type 1 STP or Type 3, 4, or 5 UTP copper cable. Each port is
independently configurable to support either 4 Mbps or 16 Mbps operation.
TRSM Configurable
Bridge Modes
The TRSM is architected to support both source routed or transparent
traffic types in the following modes:
■
Transparent (T)
■
Source Routing (SR)
■
Source Routing-Transparent Bridge (SRT)
Transparent
The TRSM fully complies with the IEEE 802.1d bridging standard, which
means that the module:
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Learns source addresses from packets transmitted by stations on LANs
attached to TRSM ports
■
Ages addresses of stations on attached LANs that have not transmitted a
packet for a prolonged time
■
Stores and forwards packets from one attached LAN to another
■
Uses the Spanning Tree protocol for loop detection
The TRSM automatically “learns” the MAC-layer addresses of the stations on
its attached networks, and then forwards packets to their appropriate
destinations. Packet forwarding is based on learned or statically configured
MAC addresses. The TRSM can learn up to 8192K addresses. Additional
addresses are learned as addresses are aged out. All addresses are stored in