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

The Cisco Transport Planner supports the following topologies:

An example of each topology is given in this chapter.

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.

Single Span Topology

The following figure 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 1. Single-Span Topology Example

Multiple Span Topology

The following figure shows as 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 2. Multispan Topology Example

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.

Closed Ring Topology

The following figure shows an example of a closed ring configuration. Here the traffic flows in a circular manner across the network.

Figure 3. Closed Ring Topology Example


Hubbed Ring Topology

The following figure 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 4. Hubbed Ring Topology Example


Mesh Topology

The following figure 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. Mesh Ring Topology Example