Chapter 1: Overview
42
Port Numbers on the AT-SBx31GC40 Line Card
The AT-SBx31GC40 Line Card has two port numbers for each transceiver
slot. The numbers are displayed on the front panel alongside and above
the slots in the top row and alongside and below the slots in the bottom
row. For instance, the first transceiver slot in the top row has the port
numbers 0 and 2 and the slot beneath it has the port numbers 1 and 3.
(The port numbers 2 and 4 are omitted from the first two slots in the top
row on the faceplate to allow for the model name.)
A transceiver uses either one or both port numbers of a slot, depending on
whether its a SFP or an CSFP transceiver. A CSFP transceiver is
assigned two port numbers because its two connectors function as
independent network connections. You may use the two port numbers of a
transceiver to configure the ports independently. The left-hand fiber
connector is assigned the lower number of a slot and the right-hand
connector is given the higher port number. For example, the left-hand fiber
connector of an CSFP transceiver in the first top slot is assigned the port
number 0 and the right-hand connector is given the port number 2.
Figure 18 illustrates the port numbers for the first two slots when they
contain CSFP transceivers.
Figure 18. 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
Port 0 Port 2
Port 1 Port 3