363-206-305
Applications
Issue 3 June 2000
2-3
Ring Topologies
2
The need to prevent service outage caused by network failure has created a new
class of applications. The 2000 Product Family offers a wide range of self-healing
network features that automatically protect against service outage caused by
cable cuts and equipment failures, which in turn protect customers and generate
increased revenue. These self-healing features include flexible DACS-based
restoration with the
ITM XM
controller,
SLC
®
-2000 2- and 4-fiber rings, DDM-2000
OC-3 and OC-12 virtual tributary 1.5 (VT1.5) and STS-1 path switched rings,
SLC
-2000 Access System path switched rings, and DDM-2000 FiberReach VT1.5
path-switched rings.
DDM-2000 FiberReach, DDM-2000 OC-3, DDM-2000 OC-12, and
SLC
-2000
Access System self-healing rings offer the performance and administrative
benefits demonstrated by the successful Lucent FT Series G Ring Diversity
Switch. Since the DDM-2000 FiberReach, OC-3, OC-12, and FT-2000 path
switched rings operate in an integrated, single-ended fashion, complex network-
level coordination is not necessary to restore traffic. This means restoration is
faster and more reliable. Furthermore, bandwidth administration and network
reconfigurations (for example, adding or deleting nodes) can be easier.
The DDM-2000 FiberReach, OC-3, and OC-12, and
SLC
-2000 path-switched
rings operate as shown in Figure 2-1(a). Traffic entering a path switched ring node
is sent onto both rotations of the ring. At the receiving node, the signal having the
highest integrity (based on SONET path information) is selected and dropped as
outgoing traffic. At intermediate nodes, the traffic is "passed-through" without
changing the SONET path information. The DDM-2000 time slot interchange (TSI)
capabilities make the provisioning of add/drop and pass-through traffic quick and
easy.
The self-healing nature of the path switched ring is shown in Figure 2-1(b). In this
case, the fiber failure between nodes B and C causes node B to switch from the
counterclockwise ring to the clockwise ring, thus maintaining service between
node A and C.
To Next Page
Loading...
Need help?
General
