Modeled Network Examples
This chapter provides examples of typical optical networks you can model using the Cisco Transport Planner.
This chapter contains the following section:
Supported Cisco Transport Planner Topologies
5.1 Supported Cisco Transport Planner Topologies
The Cisco Transport Planner supports the following topologies:
•Linear (Single-Span Topology or Multispan Topology)
•Ring (Hubbed Ring Topology or Closed Ring Topology)
An example of each topology is given in this chapter.
5.1.1 Linear Topologies
In a linear topology, the nodes are arranged in a line and are connected to two other adjacent nodes. However, the first and last node are not connected. There are two types of linear topologies, single-span and multispan.
126.96.36.199 Single-Span Topology
Figure 5-1 shows an example of a single-span topology. This topology is characterized by a single span link. It can support only two terminal sites (full terminal or flexible channel-count terminal) without any intermediate line amplifier or optical add/drop multiplexing (OADM) sites.
Figure 5-1 Single-Span Topology Example
188.8.131.52 Multispan Topology
Figure 5-2 shows an example of a multispan topology. This configuration is characterized by the presence of two terminal sites (full terminal or flexible channel-count terminal) with intermediate OADM or line amplifier nodes. In a multispan configuration, specific wavelengths are terminated at different points in the span and only unprotected traffic can be provisioned.
Figure 5-2 Multispan Topology Example
5.1.2 Ring Topology
In a ring topology, each node is connected to exactly two other nodes, forming a circular configuration. It requires at least three nodes to form a ring. There are two types of ring topologies—closed ring and hubbed ring.
184.108.40.206 Closed Ring Topology
Figure 5-3 shows an example of a closed ring configuration. Here the traffic flows in a circular manner across the network.
Figure 5-3 Closed Ring Topology Example
220.127.116.11 Hubbed Ring Topology
Figure 5-4 shows an example of a hubbed ring topology, also knows as an open ring. In this configuration, at least one of the sites must be a hub site, where all channels are terminated. At the hub site, no traffic is expressed from one side to another, hence forming a break in the ring.
Figure 5-4 Hubbed Ring Topology Example
5.1.3 Mesh Topology
Figure 5-5 shows an example of a mesh topology where each node is connected to one or more nodes. This configuration provides maximum redundancy to the network.
Figure 5-5 Mesh Ring Topology Example