Multiplex-Section Shared Protection Rings; Two-Fiber Ms-Springs; Chapter 8 Sdh Topologie And Upgrade - Cisco ONS 15600 Reference Manual

8.3 Multiplex-Section Shared Protection Rings

Figure 8-1
flows from Slot 1/Port 1 at Node 1 to Slot 1/Port 1 at Node 2. You create the protect path by creating a
1+1 configuration with Slot 2/Port 1 and Slot 2/Port 1 at Nodes 1 and 2.
Figure 8-1
Node 1
8.3 Multiplex-Section Shared Protection Rings
The ONS 15600 SDH can support up to 32 multiplex section-shared protection rings (MS-SPRings).
Because the working and protect bandwidths must be equal, you can create only STM-16 or STM-64
MS-SPRings (that is, you cannot create an MS-SPRing with a mixture of STM-16 and STM-64 line
rates). For information about MS-SPRing protection channels, see the
Circuits" section on page
Note For best performance, MS-SPRings should have one LAN connection for every ten nodes in the
MS-SPRing.

8.3.1 Two-Fiber MS-SPRings

In two-fiber MS-SPRings, each fiber is divided into working and protect bandwidths. For example, in an
STM-16 MS-SPRing, VC4s 1 to 8 carry the working traffic, and VC4s 9 to 16 are reserved for protection
(Figure
direction on the second fiber. Cisco Transport Controller (CTC) circuit routing routines calculate the
shortest path for circuits based on many factors, including user requirements, traffic patterns, and
distance. For example, in
1, unless that fiber is full, in which case circuits will be routed to Fiber 2 through Node 3 and Node 2.
Traffic from Node 0 to Node 2 (or Node 1 to Node 3) can be routed on either fiber, depending on circuit
provisioning requirements and traffic loads.
Cisco ONS 15600 SDH Reference Manual, Release 9.0
8-2
shows two ONS 15600 SDH nodes in a point-to-point ADM configuration. Working traffic
Point-to-Point ADM Configuration
Slot 1/Port 1 to Slot 1/Port 1
Slot 2/Port 1 to Slot 2/Port 1
7-14.
8-2). Working traffic (VC4s 1 to 8) travels in one direction on one fiber and in the opposite
Figure 8-2, circuits going from Node 0 to Node 1 will typically travel on Fiber
Node 2
Working Path
Protect Path
Chapter 8 SDH Topologies and Upgrades
"7.7 Protection Channel Access
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