Supported Cisco Transport Planner Topologies
The Cisco Transport Planner supports the following topologies:
- Linear (Single Span Topology or Multiple Span Topology)
- Ring (Hubbed Ring Topology or Closed Ring Topology)
- Mesh Topology
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.
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.
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.
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.
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.