Basic Network Rules; Network Backplane Restrictions - 3Com CoreBuilder 5000 User Manual

Implementing 100BASE-TX FastModules in the Network

Basic Network Rules

This section lists basic network rules for constructing your network
using Fast Ethernet:
For hardware-specific information on the 100BASE-TX Workgroup
FastModule, refer to Appendix A, Specifications.
The 100BASE-TX Workgroup FastModules are a Class 1 repeater. A
Class 1 repeater has an internal delay that functions as follows:
Only one repeater can exist between any two DTE devices within
a single collision domain when you use two maximum cable
length segments.
An internal delay is the time delay between the system's sensing
of the first data bit received and the sensing of the first data bit
transmitted on a 100 Mbps network.
Multiple 100BASE-TX Workgroup FastModules on the same network
(single backplane channel) makes 1 repeater.
The maximum UTP cable length between hub and connected
workstations is 100 meters (328 feet).
Use 2-pair Category 5 UTP or STP cable for backbone connections.
Backbone cabling is the main transmission medium used to
interconnect workgroups on a network.
Use with other switching FastModules except when other switching
FastModules are configured with VLANS (for detailed information on
switching fast modules, refer to the CoreBuilder 5000 FastModule
User Guide).

Network Backplane Restrictions

The CoreBuilder 5000 hub has capacity for four Fast Ethernet channels
(FastChannels). When you use assign a FastModule backplane port to
a CoreBuilder 5000 FastChannel, one or more backplane channels
become unavailable for use.
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