Choosing A High Speed Flow Control Mode; Symmetric Mode; Table 3-13. High Speed Flow Control Configuration Screen Fields - Nortel BayStack 450 Using Manual

Using the BayStack 450 10/100/1000 Series Switch
Table 3-13. High Speed Flow Control Configuration Screen Fields
Field
Autonegotiation
Flow Control
Preferred Phy
Active Phy

Choosing a High Speed Flow Control Mode

The High Speed Flow Control feature allows you to control traffic and avoid
congestion on the gigabit full-duplex link. If the receive port buffer becomes full,
the BayStack 450 switch issues a flow-control signal to the device at the other end
of the link to suspend transmission. When the receive buffer is no longer full, the
switch issues a signal to resume the transmission.
You can choose Symmetric or Asymmetric flow control mode:

Symmetric Mode

This mode allows both the gigabit MDA port and its link partner to send flow
control pause frames to each other.
3-36
Description
When enabled, the port only advertises support for 1000 Mb/s operation, in
full-duplex mode.
Default Value Enabled
Range Enabled, Disabled
Allows you to control traffic and avoid congestion on the gigabit MDA port. Two
modes are available (see
page 3-36 for details about the two modes). Autonegotiation must be disabled
for this port when using this feature.
Default Value Disabled
Range Disabled, Symmetric, Asymmetric
Note:
The following two fields only appear when a (single MAC) MDA with a
separate redundant Phy port is installed.
Allows you to choose the preferred Phy port; the other Phy port reverts to
backup.
Default Value Right
Range Right, Left
Indicates the operational Phy port.
"Choosing a High Speed Flow Control
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