3com 2948-SFP Plus 用户指南

A

PPEnDIX 

B

: 

D

EVICE 

S

PECIFICATIOn AnD 

F

EATURES

Line Frequency 

 

50/60 Hz

Input Voltage   

 

100–240 Vac (auto range)

Switch 2948-SFP Plus   

1.5 Amp (Max)

Maximum Power  
Consumption

Switch 2948-SFP Plus   

70 Watts

Switch 2948-SFP Plus   

238.9 BTU/hr 

This section describes the device features. The system supports the  
following features:

Table 11 Features of the Baseline Switch 2948-SFP Plus  

Auto-negotiation   

 

The purpose of auto-negotiation is to allow a device to advertise 

 

 

 

 

 

modes of operation. The auto-negotiation function provides the  

 

 

 

 

 

means to exchange information between two devices that share a  

 

 

 

 

 

point-to-point link segment, and to automatically configure both   

 

 

 

 

 

 

devices to take maximum advantage of their abilities.

 

 

 

 

 

Auto negotiation is performed totally within the physical layers  

 

 

 

 

 

during link initiation, without any additional overhead to either  

 

 

 

 

 

the MAC or higher protocol layers. Auto-negotiation allows the  

 

 

 

 

 

ports to  do the following:

 

 

 

 

 

  Advertise their abilities

 

 

 

 

 

  Acknowledge receipt and understanding of the common  

 

 

 

 

 

    modes of operation that both devices share

 

 

 

 

 

  Reject the use of operational modes that are not shared by  

 

 

 

 

 

    both devices

 

 

 

 

 

  Configure each port for the highest-level operational mode  

 

 

 

 

 

     that both ports can support