3Com TR manual Setting Port Speed, Setting Forwarding Mode, Dynamic Cut-Thru Threshold%, Mbps

4-8CHAPTER 4: CONFIGURING WITH THE VT100 INTERFACE

ring ahead in the queue. The frame that has been buffered for the busy or down queue is discarded so that deliverable packets can proceed.

■Disabled—In the disabled mode, neither Flow Control or Non-blocking are in use.

1Set this field to one of the aforementioned fields by toggling the [Space Bar].

2Press [Return].

Setting Port Speed

Speed sets the data rate of ports. Choices:

■16 Mbps (default)

■4 Mbps

1Set this field by toggling the [Space Bar].

2Press [Return].

Setting Forwarding Mode

Set the forwarding mode for individual ports using this field. Choices:

■Store & Forward—In this mode, packets are received and buffered (stored) in their entirety until they are forwarded. Errored frames will not be for- warded on the source ring. Although this guaran- tees packet stability, it also involves a transit delay.

■Cut-thru—Cut-thru avoids the transit delay found in standard store-and-forward methods. Cut-thru can only be applied between ports that are operat- ing at the same wire speed or from a high-speed port to a low-speed port.

■Dynamic Cut-thru—Dynamic Cut-thru monitors the error rates on the port. If a user-defined thresh- old is exceeded, the switch port changes to store-and-forward until the error rate reduces. Once the error rate is reduced, the switch returns to cut-thru mode.

1Set this field by toggling the [Space Bar].

2Press [Return].

Dynamic Cut-Thru Threshold%

The Dynamic Cut-Thru Threshold% field allows you to view the forwarding mode threshold percentage, which determines the degree to which errored pack- ets are allowed to pass before the Switch 2000 TR reverts to Store & Forward mode. These thresholds apply only when the Switch 2000 TR is configured in Dynamic Cut-thru mode. The two threshold fields are:

■Rising Threshold—When this threshold is exceeded, the Switch 2000 TR reverts to Store&Forward mode.

■Falling Threshold—When this threshold is crossed, the Switch 2000 TR reverts to Cut-thru mode.

Setting the Locally Admin. Address

The Locally Administered Address field allows you to assign individual MAC addresses to each port. This feature is useful for identifying specific ports by their addresses.