Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Applications
Issue 3 June 2001 2-25
Dual Homing 2
End-users are demanding service with higher and higher availability. Service
providers are responding with tariffs that rely on self-healing networks to offer
such high availability service. Some of these tariffs even call for penalties for the
service provider when service is interrupted or has a high error rate. The Lucent
SONET product family offers many options for meeting these service needs.
OC-1 Ring transport on OC-3 Ring and OC-3 Ring transport on OC-12 ring
networks can be implemented in dual homing configurations.
OC-1 Ring Transport on OC-3 Ring 2
Dual homing offers even more survivability than a single-homed network, as even
the catastrophic failure of a host node can be protected. Figure 2-16 shows a
dual-homed OC-1 extension from two remote nodes on an OC-3/OC-12 access
ring. OC-1 extensions from OC-12 rings are available in R11 using OC-12 optics
in the OC-3 shelf. The host nodes can be two DDM-2000 OC-3/OC-12 or two
SLC -2000 Access Systems, or one DDM-2000 OC-3/OC-12 Multiplexer and one
SLC -2000 Access System.
Path protection switching is employed for dual-homed applications, just like in
single-homed applications. That is, 60 millisecond path switching is supplied by
the remote DDM-2000 FiberReach nodes and the DDM-2000 OC-3 or OC-12
systems in the wire center. The OC-3 host node configuration differs from that
used for single-homing because each host node terminates only one leg of the
OC-1 extension. At each host node, a connection is made from the single OC-1
extension to just one rotation of the OC-3/OC-12 host ring. 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.
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.