GarrettCom 6K8 Manual De Usuario

Magnum 6K8-Series Industrial Field Switch             Installation and User Guide   (04/07) 

attempting to transmit to one 100Mb port, and in other protracted heavy traffic situations.  

Magnum 6K8-Series Switches implement the 802.3x flow control (non-

blocking) on Full-Duplex ports, which provides for a “PAUSE” packet to be transmitted 

to the sender when the packet buffer is nearly filled and there is danger of lost packets. 

The transmitting device is commanded to stop transmitting into the 6K8-Series Switch 

port for sufficient time to let the Switch reduce the buffer space used. When the available 

free-buffer queue increases, the Switch will send a “RESUME" packet to tell the 

transmitter to start sending the packets. Of course, the transmitting device must also 

support the 802.3x flow control standard in order to communicate properly during 

normal operation. 

Note: When in Half-Duplex mode, the 6K8-Series Switch implements a backpressure 

algorithm on 10/100 MB ports for flow control. That is, the switch prevents frames from 

entering the device by forcing a collision indication on the half-duplex ports that are 

receiving. This temporary “collision” delay allows the available buffer space to improve 

as the switch catches up with the traffic flow. The flow control option may 

network. By default the Flow control is disabled. 

Receiver Sensitivity and Transmitter Power are the parameters necessary to 

compute the power budget. To calculate the power budget of different fiber media 
installations using Magnum products, the following equations should be used: 
OPB (Optical Power Budget) = P

T

 (min) - P

R

 (min) 

      

 where P

T 

= Transmitter Output Power, and P

R

 = Receiver Sensitivity 

 Worst case OPB = OPB - 1dB(for LED aging) - 1dB(for insertion loss) 
   Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km] 
 

where the “Cable Loss” for 62.5/125 and 50/125

µm

 (Mm) is 2.8 dB/km,  

 

and the “Cable Loss” for 100/140 (Multi-mode) is 3.3 dB/km, 

 

and the “Cable Loss” for 9/125 (Single-mode) is 0.5 dB/km 

 

and the “Cable Loss” for 9/125 (Single-mode) is 0.4 dB/km (LXSC25) 

 

and the “Cable Loss” for 9/125 (Single-mode) is 0.25 dB/km 

(LXSC40) 
 

and the “Cable Loss” for 9/125 (Single-mode) is 0.2 dB/km (LXSC70)

 

 
The following data has been collected from component manufacturer’s (Agilent’s and 
Lucent’s) web sites and catalogs to provide guidance to network designers and installers. 

 
 

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