Mounting KIT Instructions, Problem Solving

Power Supply

Power problems can be the cause of serious failures and down- time in your network. Ensure that the power input to your system is clean and free from sags and surges to avoid unforeseen net- work outages. We recommend that you install power condition- ing, especially in areas prone to black outs, power dips and electrical storms.

he unit is intended to be grounded. Ensure it is connected to earth ground during normal use. Installing proper grounding helps to avoid damage from lightning and power surges.

Power Up

Use the following sequence to power up the Baseline 10/100 Switch 24 Port 10BASE-T/100BASE-TX plus 1-Port 1000BASE-T:

Check the network connections and cables.

Connect the power supply cable to the appropriate power

Tsocket on the rear panel of the unit; refer to 7 or 8.

Connect the plug to the power supply outlet socket and switch on the power supply at the socket. If you are using

the Advanced Redundant Power System, ensure it is pow- ered on.

When the switch is powered on, the Power/Self Test LED should first flash green, then stay lit. If it does not, refer to 6.

Spot Checks

At frequent intervals you should visually check the Baseline 10/100 Switch 24 Port 10BASE-T/100BASE-TX plus 1-Port 1000BASE-T. Regular checks can give you an early warning of a possible failure; any problems can then be attended to when there will be least effect on users. Check the following:

Cabling	Check that all external cabling connections are
	secure and that no cables are pulled taut.
Cooling fans	Where possible, check that the cooling fans are
	operating by listening to the unit. The fans are
	fitted near to the front right hand side of the
	unit (when viewed from the front).

If you experience any problems operating the Baseline 10/100 Switch

24Port 10BASE-T/100BASE-TX plus 1-Port 1000BASE-T, refer to “Problem Solving” on page 4.

MOUNTING KIT INSTRUCTIONS

Introduction

The Baseline 10/100 Switch 24 Port 10BASE-T/100BASE-TX plus 1-Port 1000BASE-T is supplied with two mounting brackets and four screws. These are used for rack mounting the unit. When mounting the unit, you should take note of the guidelines given in “Positioning the Switch” on page 3.

3Insert the two screws supplied in the mounting kit and fully tighten with a suitable screwdriver.

4Repeat the two previous steps for the other side of the unit.

5Insert the unit into the 19-inch rack and secure with suitable screws (not provided).

6Reconnect all cables.

Rack Mounting the Units

he Baseline 10/100 Switch is 1U high and will fit a standard 19-inch rack.

CAUTION: Disconnect all cables from the unit before continuing. Remove the self-adhesive pads from the underside of unit, if already fitted.

1Place the unit the right way up on a hard, flat surface with the front facing towards you.

2Locate a mounting bracket over the mounting holes on one side of the unit.

PROBLEM SOLVING

Refer to the information about LEDs given earlier in this guide to see if the problem can be identified and rectified. Here are some common problems that can occur:

Link Status LED not lit for a port that has a connection.

here is a problem with this connection. Check that:

The device being connected to is powered on and operating correctly.

The cable is connected at both ends. That you are using a TP cable that is:

■‘Straight through’, to connect an MDIX port to an MDI port.

■‘Cross-over’, to connect an MDIX port to an MDIX port, or an MDI port to an MDI port.

TThe cable is not damaged.

If the connection is to a workstation, that the workstation’s network interface is installed and configured correctly.

All Activity LEDs appear to be lit continually. There may be broadcast storms on the network. Remove port connections one

at a time, waiting a few seconds between each port. If the LEDs go off after removing a port connection, the device that was connected to that port is introducing an excessive amount of broadcast frames to the network (some pieces of network equipment operate by sending out broadcast frames regularly). Refer to the documentation that accompanies the device for information on disabling the broadcast operation.

If the problem persists and the unit still does not operate successfully, contact your supplier with the following information before returning the unit:

Product number and serial number (printed on a label sup-

Tplied with the unit)

A brief description of the fault

10BASE-T specifications

3Com 10BASE-T is a networking technology that plays a foundational role in local area networks (LANs). Introduced in the early 1990s, it quickly became one of the most widely adopted Ethernet standards, enabling reliable data transmission over twisted-pair cabling. Designed to operate at speeds of 10 megabits per second, 10BASE-T facilitated the transition from older coaxial cable systems to more flexible cabling options, paving the way for more robust and scalable network infrastructures.

One of the defining features of 3Com 10BASE-T is its use of unshielded twisted pair (UTP) cabling, specifically Category 3 cabling at its inception. This choice of cabling allowed for easier installation and lower costs compared to coaxial cables. Furthermore, the standardized cabling allows for distances of up to 100 meters between network devices, making it suitable for various office layouts. The connectors used with 10BASE-T networks are RJ-45 connectors, which have become a staple in networking.

Another characteristic of 10BASE-T is its method of signaling. It employs Manchester encoding, which speeds up error detection and improves resilience against noise. This coding scheme allows for the transmission of 0s and 1s over a single twisted pair of wires, adding an extra layer of efficiency to the network's operation. The design also includes a built-in collision detection mechanism, which helps manage data traffic effectively, thereby maintaining network integrity.

A defining technology of 3Com's implementation of 10BASE-T is its ability to support a star topology. Unlike previous bus topology systems that relied heavily on coaxial cables, the star topology allows for individual connections to a central hub or switch. This setup not only enhances fault tolerance—since a failure in one cable does not impact other network segments—but also simplifies network management and troubleshooting.

Additionally, 3Com's 10BASE-T technology supports auto-negotiation, allowing connected devices to automatically determine the best speed and duplex setting for communication. This adaptability makes it easier to integrate newer devices into existing networks and ensures smoother transitions as technology evolves.

In summary, 3Com 10BASE-T represents a significant advancement in networking technology, characterized by its use of twisted-pair cabling, efficient Manchester encoding, star topology, and auto-negotiation capabilities. Its contributions set the stage for the development of faster and more advanced Ethernet standards, cementing its place in the history of computer networking.