One Vt1.5 Circuit On One Sts; Figure - Cisco 15454-DS1-14= - 1.544Mbps Expansion Module Reference Manual

Chapter 11 Circuits and Tunnels
For example, if you create a VT1.5 circuit from an STS-1 on a drop card, two VT matrix STS ports are
used, as shown in
card, no additional logical STS ports are used on the VT matrix. In fact, you can create up to 28 VT1.5
circuits using the same STS-1 port. However, if the next VT1.5 circuit originates on a different STS, an
additional pair of STS ports on the VT matrix is used, as shown in
VT1.5 circuits on different EC-1 STSs and mapped each to an unused outbound STS, the VT matrix
capacity would be reached after you created 12 VT1.5 circuits in the case of the XCVT or XC10G cards,
or 48 VT1.5 circuits in the case of the XC-VXC-10G card.

Figure 11-3

Source
EC-1
Source
EC-1
78-18106-01
Figure 11-3. If you create a second VT1.5 circuit from the same STS port on the drop

One VT1.5 Circuit on One STS

VT1.5 circuit #1 on STS-1
1 VT1.5 used on STS-1
27 VT1.5s available on STS-1
XCVT/XC10G Matrices
STS Matrix
VT1.5 Matrix
VT1.5 circuit #1 on STS-1
1 VT1.5 used on STS-1
27 VT1.5s available on STS-1
XC-VXC-10G Matrices
STS Matrix
VT1.5 Matrix
2 STSs total used
22 STSs available
2 STSs total used
OC-192
94 STSs available
Cisco ONS 15454 Reference Manual, R8.5
11.3 Cross-Connect Card Bandwidth
Figure 11-4. If you continued to create
Drop
OC-12
Drop
STS
VT1.5
11-13