Accton Technology 12mi SNMP, 12i manual Setting the Communication Mode The 100BASE-TX

Fast EtherHub 3500 System User’s Guide

Setting the Communication Mode - The 100BASE-TX and

100BASE-FX SmartExtender Modules both support half and full-duplex communications. The hub uses auto-negotiation to determine the transmission mode for any new connection made to these modules. However, if a connected device does not also support auto-negotiation, and a link cannot be established using half duplex (i.e., the last state tested by auto-negotiation), then you must manually set the transmission mode for the concerned port to full or half duplex via on-board configuration (Chapter 4) or using optional network management software.

Bridging Functions - The SmartExtender Modules form a separate segment (i.e., collision domain) from the rest of the ports in the stack. They therefore provide fully transparent bridging functions which automatically learns node addresses required to filter and forward traffic based on the destination address (i.e., traffic is filtered if the destination address is in the local collision domain, or forwarded if the destination is in another segment).

Note: Devices connected to the SmartExtender Module exist in a separate segment, and cannot be controlled by a management agent in the stack.

Switching Functions - These modules also provide functions commonly found on an Ethernet switch. The scheme used to process data packets is automatically adjusted to optimize system performance. Fragment-freecut-through or store-and- forward processing may be used depending on the current error rate. (Refer to Data Switching with the SmartExtender Modules in Chapter 1 for a detailed discussion of these processing methods.)

In addition to the features listed above, the extender modules also use back pressure to eliminate frame loss when its buffers fill, by “slowing” the traffic received from end stations or segments connected directly to this port.

2-10 Installing the System