Transition Networks E-PSW-TX-02 Installing Network Cable continued, 100BASE-FX, MAC Address Table

Installing Network Cable (continued)

Connecting Fiber Cable to TX/RX Connectors

(100BASE-FX)

Effective cable distances are determined by ambient RF noise and by signal loss in the cable. Since fiber has a low signal loss/meter and is invulnerable to RF noise, fiber can be used to extend distances.

OPTICAL POWER LOSS BUDGET

An 11dB loss budget, as measured by a fiber optic power meter, is allowed per link. A typical performance rating for standard grade fiber operating at 1350 nm is approximately 1dB-2dB loss per 1000 meters of cable. Approximately 0.5dB-2.0dB loss per connection point is typical, depending on how well the connection has been made.

FAST ETHERNET COLLISION DOMAIN

When installed in a legacy 10BASE-T Ethernet network, the Transition Networks’ pocket switch segments network traffic on the original 10Mb/s Ethernet collision domain into two distinct 10Mb/s Ethernet collision domains.

			D	Collisio
				n	Do
		A/C				m	ai
	M
S								n
C

Existing 10 Mb/s Network

100 meters

Install Transition Networks' Pocket Switch

To Divide Repeater Stack Collision Domain

NOTE: Installing full-duplex fiber cable avoids collision domain considerations and extends distances up to 2000 meters.

A Fast Ethernet collision domain can have ONLY ONE CLASS I repeater OR TWO CLASS II repeaters.

Refer to the 512-Bit Rule (page18) regarding Fast Ethernet collision domains before installing half-duplex100BASE-FX cable (≤ 415 meters).

INSTALLING CABLE

			D	Collisi
	/			on	D
	A	C				o
	M					m
						a
C	S					i
				10 Mb/s		n

100 meters

			D	Collis
		C
	/
	A
	M
C	S

10 Mb/s

100 meters

ion

D

o

ma i n

To install 100BASE-FX cable:

1.Locate or build 100BASE-FX cables with the following characteristics:

•803.2u compliant (See page 28)

•male ST transmit and receive fiber connectors installed at both cable ends.

2.At Transition Networks’ pocket switch, connect transmit cable connector at one end of fiber cable to ST connector marked with an “outbound” arrow; connect receive cable connector to ST connector marked with an “inbound” arrow.

3.Connect cable installed at transmit (TX) connector of Transition Networks’ pocket switch at receive (RX) connector of device at other end; connect cable installed at receive (RX) connector at transmit (TX) connector of device at other end of fiber cable.

21 Transition Networks’

Ideally, the system administrator defines collision domain segments so that most traffic on each segment is local to the segment.

MAC Address Table

The dynamic internal routing table of the Transition Networks’ pocket switch provides self learning capabilities for up to 8192 MAC addresses of incoming and outgoing packets. Once a network node address is stored in the MAC address table, data packets addressed to that node are sent directly. Packets whose destination address is on the same CSMA/CD collision domain as the packet source address are discarded by the pocket switch. NOTE: The MAC address table is volatile and disappears when the pocket switch is powered off or reset.

Pocket Switch 6