DWDM network configurations are based on many factors, including applications and protocols, distances, usage, network access, and the legacy network.The topology of the architecture can be any of the following

1) Point to Point

2) Ring

3) Mesh (Partial or Full)

Point to Point: This architecture can be as simple as two locations directly connected or a configuration that utilizes an OADM to break the network into multiple point-to-point segments. These networks have the characteristics of ultra-high-speed channels,high integrity and reliability, and fast path restoration. The distance between transmitters and receivers can be several hundred kilometers with less than 10 amplifiers.

Ring: As rings are utilized in many SONET networks, many MAN networks utilize ring architectures with OADM to add and drop wavelengths. When rings are used in MAN networks, they typically span less than 50 Km and utilize a small number of wavelengths and nodes. In long-haul networks, SONET rings can be built in combination with DWDM. Because SONET can be transported across a DWDM span, congested routes such as Chicago to LA might utilize DWDM, split off the SONET wavelength's at the end points, and build local SONET rings. Protection schemes like unidirectional path-switched ring (UPSR) or bidirectional line-switched ring (BLSR) can be used in ring configurations that utilize SONET.

Many MAN networks transport protocols transparently instead of utilizing SONET, to reduce overhead and costs. In utilizing DWDM networks in the MAN without SONET, the DWDM architecture doesn't support ring protection schemes that SONET supports, decreasing reliability.

Mesh: Mesh architectures connect all-optical nodes together with two routes, and implement intelligence in the nodes to reroute wavelengths on faults. A meshed architecture can be thought of as a router network where every router in the network has a direct connection to every other router. If a problem is detected, the traffic is routed to another path. This type of configuration can be extremely expensive to implement and manage, which points to one of the key benefits of SONET ring architectures.