Allied Telesis AT-SBx31CFC960 - Manual (Page 47)

SwitchBlade x3106 Chassis Switch and AT-SBx31CFC960 Card Installation Guide
47
Figure 22. Port Numbers for Slots with CSFP Transceivers
In contrast, the two connectors on an SFP transceiver function as a single
port, not as individual ports. Consequently, the switch assigns that type of
module one port number instead of two.
The port number of an SFP module depends on whether the module is
installed in a slot in the top or bottom row of the line card. An SFP module
in a slot in the top row is assigned the lower of the two port numbers of a
slot. For example, the port number of an SFP module installed in the first
slot in the top row is port number 0 because it is the lower of the two port
numbers of the slot. To configure the transceiver, you have to specify port
0 in the management software. The switch marks the unused port number
of the slot, in this case port number 2, as masked or eclipsed to prevent
you from using it to manage the transceiver.
In contrast, an SFP module in a slot in the bottom row is assigned the
higher number of the slot’s two numbers. For instance, an SFP transceiver
installed in the first slot in the bottom row is assigned the port number 3 by
the switch. Port 1, the unused port number of the slot, is marked as
masked by the switch and cannot be used to configure the device.
Figure 23 on page 48 illustrates the port numbers for the first four slots
when they contain standard SFP transceivers.
Port 0 Port 2
Port 1 Port 3