6-18
Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter6 Circuits and Tunnels
Cross-Connect Card Capacities
21 STSs are available for VT1.5 circuits.
Figure6-11 Example #3: VT1.5 circuit in a UPSR or 1+1 protection scheme
Figure 6-12 shows a second VT1.5 circuit that was created using STS-2. When t he seco nd VT1. 5 circu it is created:
Three more VT1.5-mapped STSs are used.
18 STSs are available on the XCVT or XC10G for VT1.5 circuits.
Figure6-12 Example #4: Two VT1.5 circuits in UPSR or 1+1 protection scheme
Unless you create VT tunnels (see the VT Tunnels section on page 6-19), VT1.5 circuits use STSs on the XCVT/XC10G VT matrix at each node through which the circuit passes.
Two STSs are used at each node in the Figure 6-9 example, and three STSs are used at each node in
the Figure 6-11 example.
61848
STS Matrix Working
Protect
XCVT-XC10G Matrices
VT1.5 circuit #1
EC-1
Drop
3 STSs total used
21 STSs available
STS
VT1.5
OC-12
OC-12
VT1.5 Matrix
Source
61849
STS Matrix Circuit #1 (working)
XCVT-XC10G Matrices
EC-1
Source
6 STSs total used
18 STSs available
Circuit #2 (working)
Circuit #1 (protect)
Circuit #2 (protect)
STS
VT1.5
VT1.5 Matrix
OC-12
OC-12
VT1.5 circuit #1
VT1.5 circuit #2
Drop
Drop