Introduction

This chapter introduces the FastHub 112T and the FastHub 124T and covers the following topics:

• Summary of Key Features

• Front Panel

• Rear Panel

• Network Configuration Overviews

Summary of Key Features

The FastHub 112T and FastHub 124T are unmanaged, autosensing Class II repeaters for workgroups and server farms. The FastHubs support both 10-Mbps and 100-Mbps connections to workstations, servers, switches, and routers. Table 1-1 summarizes FastHub features.

Table  1-1: FastHubs--Key Feature Summary

Feature	Description
Compatibility	IEEE 802.3 10-Mbps-repeater compliant. IEEE 802.3u Class II-repeater compliant. Compatible with 10/100BaseT standards and with other 10/100BaseT products.
Performance	100-Mbps peak and aggregate throughput. 10/100 autosensing automatically configures the correct speed based on the connected device.
Power redundancy	Supports connection of optional Cisco redundant power system (RPS) as a backup power source.
Internal 10BaseT/100BaseTX bridge	Supports a 10BaseT network segment and a 100BaseTX network segment. Hub ports can be in either segment and communicate with one another via the internal bridge.

Front Panel

This section describes the hub front-panel features, including the network ports and LEDs.

Network Ports

The front panel has 12 (FastHub 112T) or 24 (FastHub 124T) 10BaseT/100BaseTX network ports and a 10BaseT/100BaseTX uplink port, which are illustrated in Figure 1-1 and Figure 1-2.

The network ports support 10BaseT or 100BaseTX connections. The ports autosense what type of device (either 10BaseT or 100BaseTX) is connected and then operate at the same speed as that device.

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Note When a 10/100 device connected to the FastHub changes speeds (from 10 Mbps to 100 Mbps or from 100 Mbps to 10 Mbps) the device must reboot. The device then drops the link to the FastHub and recreates the link after rebooting. (If the device does not reboot after changing speeds, the FastHub does not detect the change in speed.)

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All ports support the 10BaseT and 100BaseT IEEE 802.3 and IEEE 802.3u specifications and connect to any 10BaseT with Category 3 or 4 unshielded twisted-pair (UTP) cable or to any 100BaseTX device with Category 5 UTP cable.

Figure 1-1: FastHub 112T--Front Panel Ports

Figure 1-2: FastHub 124T--Front Panel Ports

LEDs

This section describes how to use these front-panel LEDs:

• System status LED

• Redundant Power System (RPS) LED

• Activity/collision LEDs

• Port LEDs

Figure 1-3 is a close-up view of the LEDs that are on the FastHub front panel.

Figure 1-3: LEDs and Mode Button--FastHub Front Panel

System Status LED

The green system status (SYSTEM) LED shows whether the hub is receiving power and functioning properly, as shown in Table 1-2.

Table  1-2: LED Description--System

LED Status	Description
Off	FastHub is not powered up.
On	FastHub is operating normally.

Redundant Power System LED

The RPS LED indicates the RPS status. Table 1-3 provides a description of the LED colors and what they mean.

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Note When you are using the RPS, turn OFF the hub internal power supply by unplugging the AC power cord that is connected to the rear panel.

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Table  1-3: LED Description--RPS

Color	Description
Off	Power is OK (internal power supply is powered up), and the RPS is not connected to the FastHub.
Solid green	Power is OK (RPS is powered up and operational).
Solid amber	RPS is not operational or is not connected properly.
Flashing green	RPS and internal power supply are both powered up. Only one power source can be supplying power to the hub. If you are using the RPS, the AC power cord for the internal power supply must not be connected to the hub rear panel. If you are using the internal power supply, the RPS can be connected to the hub but must be powered down.

Collision/Activity LEDs

The FastHub has two LEDs that indicate packet collisions and activity on the 10BaseT and 100BaseTX segments. These LEDs are described in Table 1-4.

Table  1-4: LED Description--Activity/Collision

LED	Description
10	Flashing green--There is network traffic on the FastHub 10BaseT segment. Flashing amber--There are packet collisions on the FastHub 10BaseT segment.
100	Flashing green--There is network traffic on the FastHub 100BaseTX segment. Flashing amber--There are packet collisions on the FastHub 100BaseTX segment.

Port LEDs

Each network port has an LED above the port. These LEDs, as a group or individually, display information about the hub and about individual ports. Table 1-5 summarizes the three different ways (called modes) to use the LEDs.

Table  1-5: Port LED Modes Summary

Mode	Description
Port status (default)	Use the LEDs to determine the status of individual network ports. Table 1-7 describes this function.
Bandwidth utilization	Use the LEDs to determine what percentage of the hub total bandwidth is being used at any one time. Figure 1-4 and Figure 1-5 illustrate this function.
100BaseT connections	Use the LEDs to determine which ports are connected to 100BaseTX network devices.

Changing Between Modes

Table 1-6 describes how to use the Mode button on the front panel to change the LED mode of the hub. Use the LEDs to determine information about the hub based on the mode being used.

When you push the Mode button to select an LED mode, the selected mode stays active for 15 seconds before the hub returns to the default mode (port status).

Table  1-6: Changing Between Modes

For this Mode...	Push the Mode Button...	Confirm...
100	Once	Green 100 LED is on.
UTL	Twice	Green UTL LED is on.

Port Status Mode

This is the default LED mode. The numbered LEDs above the network ports show the status of the corresponding ports. The UTL LED and the 100 LED are off when the hub is in port status mode.

Table 1-7 describes how port status is indicated per port by the LED color and light pattern.

Table  1-7: LED Description--Port Status Mode

Color	Port Status
Off	No link, or link is down.
Green	Link operational.
Amber	The port is partitioned. After a packet is successfully sent over this port, the LED is green (normal operating state).

Bandwidth Utilization Mode

Use the LEDs as group to determine what percentage of the hub bandwidth is being used at any one time.

To enter UTL mode from the default mode, push the Mode button once. The UTL LED goes on. In this mode, the hub uses different sets of LEDs to the indicate bandwidth being used at either speed (10 Mbps or 100 Mbps). The more LEDs that are lit, the higher the percentage of bandwidth being used.

FastHub 112T--Port LEDs 1 through 6 in Figure 1-4 indicate 10-Mbps bandwidth, and port LEDs 7 through 12 indicate 100-Mbps bandwidth, as shown in Figure 1-4.

Figure 1-4: Bandwidth Utilization Mode for FastHub 112T

FastHub 124T--Port LEDs 1 through 12 in Figure 1-5 indicate 10-Mbps bandwidth, and port LEDs 13 through 24 indicate 100-Mbps bandwidth.

Figure 1-5: Bandwidth Utilization Mode for FastHub 124T

100BaseT Connections Mode

Use the LEDs to determine which hub ports are connected to 100BaseTX network devices, as shown in Table 1-8. To enter 100 mode from the default mode, push the mode button twice. The 100 LED goes on.

Table  1-8: LED Description--100BaseT Connections

LED Status	Description.
On	Port is connected to a 100BaseTX network device.
Off	Port is not connected or is connected to a 10BaseTX network device.

Rear Panel

The hub rear panel has the following connectors:

• AC power receptacle--Use the supplied AC power cord to connect the hub to an AC power source through this receptacle.

• Redundant power system (RPS) receptacle--Connect the hub to an (optional) DC RPS through this receptacle. If you use the RPS, do not connect the supplied AC power cord to the AC power socket.

Only one power source can supply power to the hub at any one time.

Figure 1-6: Rear Panel--FastHub 112T and FastHub 124T

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Note Although the hub rear panel has labels for a console port and an AUI port, these ports are not used.

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Network Configuration Overviews

This section shows two possible network configurations using the FastHub 112T and FastHub 124T, as well as other members of the FastHub product line.

Workgroups

You can create 10- and 100-Mbps workgroups by interconnecting FastHubs (such as FastHub 112T, FastHub 124T, FastHub 216T, and FastHub 300 series) as shown in Figure 1-7.

Figure 1-7: FastHubs in a Workgroup Application

Server Farms

You can use the FastHubs to create 10- and 100-Mbps server farms to increase centralized and decentralized server performance as shown in Figure 1-8.

Figure 1-8: FastHubs in a Server Farm Application