Cabletron Systems 2H23-50R, User Manual

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Chapter 1: Introduction
1-4 2H23-50R/2H33-37R User’s Guide
1.3.1 Connectivity
The 2H23-50R or 2H33-37R connect to Ethernet/Fast Ethernet networks
or workstations through RJ21 ports on the front panel. Each port supports
a 25-pair cable at lengths up to 100 meters (each pair must be Category 5
compliant with an impedance of 85 to 111 ohms). The ports are IEEE
802.3 10BASE-T and IEEE 802.3u 100BASE-T compliant.
The 2H23-50R has two front panel slots (5 and 6) for optional Fast
Ethernet Interface Modules to support an uplink to Fast Ethernet
backbones or a high speed connection to a local server.
The 2H33-37R has a slot for an optional HSIM to provide additional
connectivity to high speed networking technologies such as ATM, FDDI,
and WANs.
Cables available for 100BASE-TX operation include:
• 180° angle connector (straight-through RJ2-to-RJ21)
• 180° RJ21-to-RJ45 connector
• 120° angle connector with the same options
1.3.2 Full Duplex Switched Ethernet
The optional Fast Ethernet Interface Modules for the 2H23-50R can be
configured to operate in Full Duplex Switched Ethernet mode, which
provides 200 Mbps of bandwidth.
1.3.3 Auto-Negotiation
The repeater ports and Fast Ethernet Interface Modules can auto-negotiate
the type of connection required to provide a link to another device.
During Auto-Negotiation, two devices automatically exchange
information “telling” each other what their operating capabilities are. The
Auto-Negotiation feature targets the maximum capabilities that can be
reached between the two devices. For example, an FE-100TX Fast
Ethernet Interface Module in a 2H23-50R can adjust to 100 Mbps when
the device on the other end of the connection can also adjust to 100 Mbps.
If the device on the other end of the connection can only operate at
10 Mbps, then the FE-100TX simply adjusts to 10 Mbps operation.