3Com TR manual Setting Port Personality, Setting Port Priorities, Setting Congestion Control

identified by their VLAN ID. All ports are configured by default to VLAN 1.

1Set this field by entering the desired VLAN number for the current port.

2Press [Return].

Setting Port Personality

Ports 1 through 4 on the Switch 2000 TR can be set to *Adapter* or *Hub*. In “adapter” mode, the port can connect to a token ring hub such as a SuperStack

IIHub TR. In “hub” mode, the port acts like a hub port and can support a directly-connected worksta- tion or server. Ports 5 through 12 support “adapter” mode only.

An external adapter cable can be used to directly attach workstations to ports 5 through12.

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

2Press [Return].

Setting Port Priorities

Switch 2000 TR has two fields for setting priority:

■Internal Priority—The Internal Priority field allows you to distribute the available bandwidth among the ports. High-priority ports are given priority access to internal resources, taking priority over Normal priority ports. Settings are High or Normal.

■Token Priority—The Token Priority field deter- mines the priority of a token ring port on the Switch 2000 TR when transmitting to a segment.

Port Configuration 4-7

For example: In Normal-priority a token level of 4 is reserved and all packets are transmitted with a token priority of 4 or higher, if necessary. In High-priority mode, a token level of 6 is reserved and all packets are transmitted with a token priority of 6 or higher, if necessary.

If Token Priority is disabled on a port, then packets are transmitted from that port with the priority token that is available at the time. Token Priority is turned off if disabled.

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

2Press [Return].

Setting Congestion Control

Congestion Control provides a method for determin- ing how the Switch 2000 TR reacts in high-traffic load scenarios. Rather than discarding packets, this unique feature allows you to control the flow of traffic by assigning alternate methods for traffic handling. Choices:

■Flow Control—Flow Control allows you to elimi- nate frame loss by buffering excess frames at the end station where space is available until the Switch 2000 TR’s buffers are free. Once the buffers on the Switch 2000 TR are free, the end station’s buffers are emptied to the Switch 2000 TR and packet loss is eliminated.

■Non-blocking—Non-blocking is the factory default state. In this mode frames are forwarded to available destination rings. This occurs even if a frame has been buffered due to a busy or down