363-206-295
Shelf Descriptions and Configurations
3-10
Issue 1
December 1997
OC-12 STS-1/VT1.5 Path Switched
Ring Configuration
3
Figure 3-5 shows a DDM-2000 OC-12 Multiplexer STS-1/VT1.5 path switched
ring configuration. As in the DDM-2000 OC-12 Multiplexer STS-1 ring shelf, there
is one set of OC-12 interfaces and a pair of TSI FLEX circuit packs. In this
configuration, however, there is also an IS-3 interface to a DDM-2000 OC-3
Multiplexer shelf where VT1.5 level path protection switching is completed. This
interface between DDM-2000 OC-3 and OC-12 Multiplexers is referred to as a
"0x1" interface. In this case, the DDM-2000 OC-12 Multiplexer feeds the STS-1
paths directly from the two rotations of the OC-12 ring to the OC-3 shelf.
Protection switching is done on the OC-3 Multiplexer shelf. The remaining function
units can be equipped with 3DS3, 3STS1E, or OLIU circuit packs as desired.
OLIUs can be used for optical extensions as in the OC-12 Multiplexer STS-1 level
path switched ring for interconnection to additional DDM-2000 OC-3 Multiplexer
shelves performing VT1.5 level path switching.
Figure 3-5.
OC-12 STS-1/VT1.5 Path Switched Ring Configuration
IS-3
I
3
D
S
3
I
U
I
U
I
1
1
1
1
1
1
3
D
S
3
D
S
3
T
S
I
S
O
L
O
L
T
S
T
G
T
G
1
2
I
S
M
X
M
X
D
S
1
D
S
1
D
S
1
D
S
1
D
S
1
D
S
1
D
S
1
D
S
1
M
X
M
X
5
6
7
5
6
7
C
T
L
D
S
3
L
S
Y
S
O
H
C
T
L
U
S
E
R
P
A
N
E
R
V
R
V
D
D
D
D
D
D
D
D
O
H
C
S
Y
S
C
T
U
S
E
R
P
A
T
8(P)
8(P)
1
2
3
4
1
2
3
4
1
1
R
V
0
R
V
0
0
0
S
1
S
1
S
1
S
1
S
1
S
1
S
1
S
1
L
N
E
L
L
2(P)
2(P)
2(P)
2(P)
2(P)
2(P)
2(P)
2(P)
2(P)
2(P)
3
3
3
3
1
T
G
DDM-2000
DDM-2000
2
1
1
T
G
OC-12 Shelf
OC-3 Shelf
1
7
7
C
A
P
P
B
L
K
1
7
7
C
A
P
P
B
L
K
3
S
T
S
1
E
3
S
T
S
1
E
2
2
D
-
U
2
2
D
-
U
1
2(P)
D
S
3
D
S
3