WAN topologies: Bus, Ring, Star, Mesh, Tiered
We’ll look at how different WAN sites are connected to each other.
Topology belongs to the layer 1 domain of the OSI model. WAN topologies are similar to LAN topologies but with little differences.
WAN topologies cover a larger area, have a larges user base. The connection links between WAN sites are a mix of different technologies — T1, T3, DSL etc..
Each WAN site is connected to no more than 2 locations.
Each WAN site is connected to 2 other sites to form a ring like structure.
A single site acts as a central connection point for several other sites. This arrangement provides for a separate route for data between any 2 sites. Also, if the central point fails…the entire WAN network goes down.
In MESH topology, several WAN sites are directly interconnected. And this arrangement of WANs is highly fault-tolerant…because, they provide multiple routes for data to flow between any 2 sites. In partial mesh, only the critical sites are directly interconnected and secondary sites are just, well...connected through star/ring arrangement.
In tiered topology, sites in ring/star formations are interconnected at different levels. And the interconnection points are organized into layers to form hierarchical groupings.