Compared to the previous network models (layer-1 design, layer-2 design, layer-3 design, MLS design) this model introduces modularity and a hierarchical structure over a non-hierarchical structure and divisions for physical, logical and functional areas within the network for different devices and components (servers, wan, wlan, lan, clients) to ease design, implementation and troubleshooting.
This model divides network functional areas into:
- Enterprise Campus contains all the functional areas to build a hierarchical, robust network that offers performance, scalability and availability.
- Enterprise Edge contains all the functional areas aggregate connectivity externally.
- Service Provider Edge contains all the resources external to the enterprise campus which in turn connect to the Enterprise edge modules.
This model divides network physical areas into:
- Building Access is used to grant end-users access to network devices and in turn resources.
- Building Distribution is used to aggregate (bring together) wiring closets.
- Building Core layers (Campus backbone sub-module) is a high-speed backbone used to switch packets as fast as possible.
The model includes the following sub-modules:
- Building Access sub-module containing end-user workstations, IP phones, printers, cameras and Layer-2 switches that connect to the Building Distribution module.
- Building Distribution sub-module (Building Distribution Layer) containing aggregation of building access devices (layer-3 switching). Traffic flows through this sub-module onto the campus backbone or core. Maintains two equal cost paths in routing table for every layer-3 network.
- Campus Backbone sub-module (Campus Core) provides redundant and fast-converging connectivity between between building buildings, server farm, and Edge Distribution.
*Enterprise Composite Network Model Diagram
This model meets the following criteria:
- The Enterprise Composite Network Model is a deterministic network (predictable) as opposed to a probabilistic network (likeliness) with clearly defined borders and demarcation points so you know where traffic is located and going.
- It increases network scalability and integrity allowing the addition of functionality without wholesale replacement.
Post by Eric on the blog CCNP Recertification on the same subject dated March 16th 2004 old but still relevant and mentions desings, models and architectures like AVVID and SAFE. Worth a read he summarises it nicely. Take note the links to the pages dont all work.
Notes and Notices:
This is a part of my personal BCMSN notes and research to assist myself in learning and understanding the concepts and theory for the BCMSN exam. I learn by making notes reading and writing things down and wish to file them where I can’t lose them. These notes are not to be seen, judged or mistaken for replacements to Cisco recognized and authorized training which I personally support and attend and suggest you undertake if you are going for the BCMSN Certification.