3Com 3CBLSG48 User Guide - Page 199

188 appendix B: DEVICE SPECIFICATION AND FEATURES Electrical Line Frequency Input Voltage Current Rating Switch 2948-SFP Plus Maximum Power Consumption Switch 2948-SFP Plus Max Heat Dissipation Switch 2948-SFP Plus 50/60 Hz 100-240 Vac (auto range) 1.5 Amp (Max) 70 Watts 238.9 BTU/hr Switch Features This section describes the device features. The system supports the following features: Table 11 Features of the Baseline Switch 2948-SFP Plus Feature Description 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