363-206-295
Transmission and Synchronization Interfaces
5-8
Issue 1
December 1997
Linear (1+1) Optical Extension Between OC-12
and OC-3
5
See Figure 5-4 and Figure 5-5. The function units in the DDM-2000 OC-12 shelf
can contain linear (1+1) protected OC-3/IS-3 circuit packs. This allows a
DDM-2000 OC-12 shelf to connect to the main slots of a DDM-2000 OC-3 shelf.
This allows more options in designing a DDM-2000 network, such as adding a
DDM-2000 OC-3 shelf off of a DDM-2000 OC-12 ring. In the transmit direction, a
circuit pack failure will cause a switch. In the receive direction, an incoming STS
signal failure or circuit pack failure will cause a switch.
Figure 5-4.
OC-12 Ring Shelf with Linear (1+1) OC-3 Low-Speed Interfaces (Transmit)
M
B
1
O
L
I
U
M
B
2
O
L
I
U
T
S
I
1
T
S
I
2
FN( )-1
FN( )-2
21 Type
OLIU
21 Type
OLIU
Linear
(1+1) Connection
22-Type OLIU
From Function Units
22-Type OLIU
OC-3 Line Switch
(Switched Together)
DDM-2000
OC-12 Shelf
DDM-2000
OC-3 Shelf
OC-3
Ring
1
Ring
1
Ring
2
Ring
2
