3Com TR - Manual (Page 65)

Port Configuration 4-7
identified by their VLAN ID. All ports are configured
by default to VLAN 1.
1 Set this field by entering the desired VLAN number for
the current port.
2 Press [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
II Hub 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.
1 Set this field by toggling the [Space Bar] to your
choice.
2 Press [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.
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.
1 Set this field by toggling the [Space Bar].
2 Press [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