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Cisco ONS 15454 Reference Manual, R8.5.x
78-18106-01
Chapter 11 Circuits and Tunnels
11.4 Portless Transmux
Cross-connect card resources can be viewed on the Maintenance > Cross-Connect > Resource Usage tab.
This tab shows:
• STS-1 Matrix—The percent of STS matrix resources that are used. 288 STSs are available on XCVT
cards; 1152 are available on XC10G and XC-VXC-10G cards.
• VT Matrix Ports—The percent of the VT matrix ports (logical STS ports) that are used. 24 ports are
available on XCVT and XC10G cards. 96 ports are available on the XC-VXC -10G card. The
VT Port Matrix Detail shows the percent of each VT matrix port that is used.
• VT Matrix—The percent of the total VT matrix terminations that are used. There are
672 terminations for the XCVT and XC10G cards. 672 is the number of logical STS VT matrix
ports (24) multiplied by the number of VT1.5s per port (28). There are 2688 terminations for the
XC-VXC-10G card. 2688 is the number of logical STS VT matrix ports (96) multiplied by the
number of VT1.5s per port (28).
To maximize resources on the cross-connect card VT matrix, keep the following points in mind as you
provision circuits:
• Use all 28 VT1.5s on a given port or STS before moving to the next port or STS.
• Try to use EC-1, DS3XM, or OC-N cards as the VT1.5 circuit source and destina tion. VT1.5 circuits
with DS-1-14 or DS1N-14 sources or destinations use a full port on t he VT matrix even though only
14 VT1.5 circuits can be created.
• Use VT tunnels and VT aggregation points to reduce VT matrix utilization. VT tunnels allow VT1.5
circuits to bypass the VT matrix on pass-through nodes. They are cross-connected as STSs and only
go through the STS matrix. VT aggregation points allow multiple VT1.5 circuits to be aggregated
onto a single STS to bypass the VT matrix at the aggregation node.
11.4 Portless Transmux
The DS3XM-12 card provides a portless transmux interface to change DS-3s into VT1.5s. For XCVT
drop slots, the DS3XM-12 card provides a maximum of 6 portless transmux interfaces; for XCVT trunk
slots and XC10G or XC-VXC-10G slots, the DS3XM-12 card provides a maximum of 12 portless
transmux interfaces. If two ports are configured as portless transmux, CTC allows you to create a
DS3/STS1 circuit using one of these ports as the circuit end point. You can create separate DS1/VT1.5
circuits (up to 28) using the other port in this portless transmux pair.
When creating a circuit through the DS3XM-12 card, the portless pair blocks the mapped physica l
port(s); CTC does not display a blocked physical port in the source or destination drop-down list during
circuit creation. Table 11-6 lists the portless transmux mapping for XCVT drop ports.
Table 11-5 VT Matrix Port Usage for One VT1.5 Circuit
Node Type No Protection BLSR Path Protection 1+1
Circuit source or destination node 2 2 3 2
Circuit pass-through node without VT tunnel 2 2 2 2
Circuit pass-through node with VT tunnel 0 0 0 0