363-206-285
Administration and Provisioning
Issue 3 June 2001
8-67
Path protection switching is employed for dual-homed applications, just like in
single-homed applications. That is, path switching is supplied by the remote
DDM-2000 FiberReach nodes and the DDM-2000 OC-3 systems in the wire
center. However, the OC-3 host node configuration is different than for single
homing. Since an OC-3 host node terminates only one leg of the OC-1 extension,
it employs a 0x1 low-speed interface to the OC-1 ring extension. The dual OC-1
circuit pack can be unprotected in a dual-homed application. Dual- and single-
homed extensions can also be mixed at a host node, allowing the access network
to be tailored efficiently to different groups of customers.
Example Cross-Connections 8
The cross-connect commands at each node in Figure 8-9 are as follows:
â– At RT1 and RT2: ent-crs-vt1:m-1-2-3,m-1-2-3:cct=twoway;
The VT signal in the ring is only passing through these sites, so two-way
cross-connections with identical addresses are provisioned here.
â– At RT3 and RT4: ent-crs-vt1:m-1-2-3,b-7-4:cct=twoway;
At these sites, the VT1.5 signal is routed between a timeslot on the OC-3
ring and a timeslot on the OC-1 ring.
â– At the DDM-2000 FiberReach: ent-crs-vt1:m-1-7-4,c-1-
4:cct=twoway;
At this site, the signal is routed from a DS1 interface to the same timeslot
on both rotations of the OC-1 ring. In the other direction, the VT1.5 signals
received from both rotations of the OC-1 ring are monitored, path
protection switching is provided, and the selected signal is routed to the
DS1 interface.
â– At CO: ent-crs-vt1:m-1-2-3,b-1-1:cct=twoway;
At this site, the signal is routed from a DS1 interface to the same timeslot
on both rotations of the OC-3 ring. In the other direction, the VT1.5 signals
received from both rotations of the OC-3 ring are monitored, path
protection switching is provided, and the selected signal is routed to the
DS1 interface.
Locked STS-3c (0x1) Broadband Services 8
Beginning with Release 5.2 DDM-2000 OC-12 Multiplexer and with Release 15.0
DDM-2000 OC-3 Multiplexer when the MAIN slots are equipped with 29-type
OLIU OC-12 optics, the OC-12 ring will transport STS-3c 0x1 services through
OC-3/IS-3 interfaces (for OC-12) or 22-type OLIU OC-3 interfaces in its function
units.
STS-3c path switching does not take place on the DDM-2000 OC-12 ring; it is
executed elsewhere in the network (e.g., when the OC-12 ring transports ATM