Matrix Port; Switch Software Features Explained; Full Duplex; Flow Control - IBM 8271 Nways F12 User Manual

Matrix Port

Switch Software
Features Explained

Full Duplex

Flow Control

When an Expansion Module is not installed, ensure the blanking plate
is secured in place.
The matrix port allows you to:
Stack the Switch with another Model F12/F24 or Model E12/E24
unit using a single Matrix Cable
Stack the Switch with up to three other Model F12/F24 or Model
E12/E24 units, if one of the units has a Matrix Module installed
The following sections explain in more detail the software features
listed in "Summary of Software Features" on page 1-2.
Throughout this chapter, the term stack refers to a number of Switch
units that are managed as a single unit. A stack can contain a single
Switch unit.
Full duplex support is provided for all ports in the stack, including
Expansion Module ports. Full duplex allows packets to be transmitted
and received simultaneously and, in effect, doubles the potential
throughput of a link. In addition, full duplex supports 100BASE-FX
cable runs of up to 2km (6562ft).
Full duplex must always be enabled at both ends of a link. If the link
uses an auto-negotiating twisted pair connection, this is done
automatically. If the link uses a fiber connection or a connection that is
not auto-negotiating, both ends must be set to full duplex mode
manually.
ATTENTION: If auto-negotiation is disabled, do not enable full duplex
on a connection to a hub or repeater.
For more information about enabling full duplex on a port, see
"Configuring a Port on the Switch" on page 4-16.
Flow control is a congestion control mechanism that is provided for all
ports in the stack, including Expansion Module ports. Congestion is
caused by one or more devices sending traffic to an already congested
port on the Switch. Flow control prevents packet loss and inhibits the
devices from generating more packets until the period of congestion
ends.

Switch Software Features Explained

1-7