User`s guide

Overview
Introduction 1-3
1.1.1 Connectivity
The SmartSwitch modules connect to Ethernet networks or workstations through the RJ21 ports on
the front panel. These ports are IEEE 802.3 10BASE-T and IEEE 802.3u 100BASE-TX
compliant. The ports support Unshielded Twisted Pair cables with an impedance between 85 and
111 ohms at lengths up to 100 meters for 10 and 100 Mbps. They also support Category 3 cable for
10 Mbps, but not 100 Mbps. Refer to the Cabletron Systems Cabling Guide for details.
The device at the other end of the twisted pair segment must meet IEEE 802.3u 100BASE-TX Fast
Ethernet network requirements for the devices to operate at 100 Mbps.
The 6H253-13 has a slot for an optional HSIM or VHSIM to provide additional connectivity to
various networking technologies.
1.1.2 Auto-Negotiation
The twisted pair ports on the front panel of the SmartSwitch modules have the ability to
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, the SmartSwitches adjust to 100 Mbps when the
device on the other end of the connection can also adjust between 10 Mbps or 100 Mbps. If the
device on the other end of the connection can only operate at 10 Mbps, then the SmartSwitches
adjust to 10 Mbps operation.
When Auto-Negotiation is supported at both ends of a link, the two devices dynamically adjust to
full or half duplex operation based on the maximum capability that can be reached between the
two devices. If the device connected to the SmartSwitch cannot auto-negotiate, the SmartSwitch
interface operates according to the capability of the other device.
1.1.3 Runtime IP Address Discovery
This feature enables the modules to automatically accept an IP address from a Boot Strap Protocol
(BootP) server on the network into NVRAM without requiring a user to enter an IP address
through Local Management.
NOTE
The fixed ports of the SmartSwitch support Category 5 UTP cabling with an impedance
between 85 and 111 ohms for 10 and 100 Mbps operation. SmartSwitch modules are
capable of operating at either 10 or 100 Mbps. The SmartSwitch automatically senses
the speed of the other device and adjusts speed accordingly.