3Com Hub 1000 SX manual Features and, Functions

1-4CHAPTER 1: INTRODUCTION

Features and	The hub can be mounted in a 19-inch standard rack or placed on a
Functions	flat surface. It supports the 1000 Mbps media access control (MAC)
	as specified in the IEEE 802.3z standard. In addition, the hub has
	these features:
	■ LED indicators report the status of each port and of hub operations. A
	meter shows the percentage of bandwidth being used within the hub.
	■ The serial console interface allows limited options for port
	configuration and, if necessary, firmware updates.
	■ Power-on self-test (POST) diagnostics determine whether the hub is
	functioning properly at power up.
	■ Frame-aging firmware improves performance by minimizing
	unnecessary frame aging and subsequent attempts to retransmit
	packets at the protocol level.
	■ Round-robin arbitration grants fair access for all ports to the hub’s
	internal bus on a packet-by-packet basis.
	■ Signal retiming restores the timing and amplitude of the received
	signal before retransmitting the signal.
	■ A carrier integrity monitor checks packets for invalid framing and
	removes invalid frames from the network.
	■ Jabber control inhibits overly long transmissions of data generated by
	the hardware failure of an attached device.