Nortel Networks 60-12T, 60-24T manual Port Partitioning

Introduction

Port Functions

This section describes port partitioning and MDI/MDI-X modes. Partitioning is an automatic function of BayStack 60-12T/60-24T 10/100 Ethernet Hub ports. Certain ports can be configured to MDI/MDI-X mode with the MDI/MDI-X button.

Port Partitioning

A port is automatically disabled by the hub when a serious error occurs, such as continuous collisions on a single packet. This process is known as autopartitioning. A partitioned port indicates an overloaded network or a malfunctioning device on the network. When the port receives a valid packet from the connected device, or is able to transmit a packet from the port, it automatically releases the port so that it becomes active again.

•Partitioning occurs at a 100 Mb/s port when there are 61 consecutive collisions.

•Partitioning occurs at a 10 Mb/s port when there are 32 consecutive collisions, or when one collision lasting as long as 575.2us has occurred.

MDI/MDI-X Modes

Adapter cards in computers and workstations usually contain media-dependent interface (MDI) ports, also called uplink ports. Most hub ports are configured as media-dependent interfaces with built-in crossover ports, called MDI-X or normal ports. By default, all BayStack 60-12T/60-24T 10/100 Ethernet Hub ports are set to MDI-X, or normal, mode. You can connect your hub to computers and workstations in MDI-X mode using a standard straight-through cable.

You need a crossover cable to connect your hub to other hubs, switches and routers if you are using a hub port in normal, MDI-X, mode. You can use a straight-through cable to connect to these devices if you configure a port on your hub to the uplink mode.

You can configure port 1 on the BayStack 60-12T/60-24T 10/100 Ethernet Hub from normal to uplink mode with the MDI/MDI-X button.

Refer to “ Cable Types and MDI/MDI-X Modes” on page 3-3 for details regarding which cable or mode to use for specific devices.