- CABLETRON Systems, Inc, SmartSwitch User's Guide 2E42-27, 2E42-27R, 2E43-27, 2E43-27R

Chapter 1: Introduction
1-4 2E42-27/2E42-27R/2E43-27/2E43-27R User’s Guide
1.4 2E4X-27 OVERVIEW
The 2E4X-27 is a 27-port high-speed network switching device that
supports traditional switching (bridging) and Cabletron Systems
SecureFast Switching Virtual Network technology. Ports 25 and 26
support optional Fast Ethernet Interface Modules and can provide uplinks
to 100BASE-TX or 100BASE-FX Fast Ethernet networks. Port 27
supports an optional High Speed Interface Module (HSIM) that provides
additional connectivity to various networking technologies such as
Asynchronous Transfer Mode (ATM) and Fiber Distribution Data
Interface (FDDI).
The 2E4X-27 is used to connect individual high-bandwidth user devices,
such as workstations, and provides a central switching point for multiple
Ethernet segments built using devices such as Cabletron Systems
HubSTACK or other third party stackable devices.
The 2E4X-27 is a tabletop unit that can be installed in a standard 19-inch
rack using the supplied rack mounting hardware.
The 2E42-27 and 2E43-27
have one universal ac power supply with
automatic voltage sensing that allows operation using 100–125 or
200–240 Vac, 50/60 Hz.
The 2E42-27R and 2E43-27R have two power supplies. The power
supplies load share 50% (+/-5%) of the power required by the device. If
one power supply fails, the remaining power supply assumes the entire
load of the device without interruption to network traffic. Each power
supply module supports its own ac input connection, which allows the
user to connect each power supply to a different ac power circuit.
1.4.1 Connectivity
Connectivity for ports 1 through 24 is different for the
2E42-27/2E42-27R and the 2E43-27/2E43-27R.
The 2E42-27/2E42-27R connects to Ethernet networks or workstations
through 24 RJ45 ports on the front panel. These ports support Unshielded
Twisted Pair (UTP) and Shielded Twisted Pair (STP) cables at lengths up
to 100 meters. The ports are IEEE 802.3 10BASE-T compliant.
The 2E43-27/2E43-27R connects to Ethernet networks or workstations
through two 50-pin RJ21 connectors. Each connector is wired for 12
ports.