SD-Access Design Consideration

SD-Access Site Reference Models

Now we will discuss Site Reference Models used in SD-Access fabric. In SD-Access Sites are classified in to following categories.

• Very Small Site
• Small Site
• Medium Site
• Large Site

Very Small Site – Reference Model

Classification of this site contains a single wiring closet, less than 2000 endpoints, Less than 8 VNs, and less than 100 APs. In this a stack switch operate in following mode: Border Node, Control plane node, and Edge Node and this type of switch is generally said as Fabric in a BOX.

Small Site – Reference Model

This type of Model is used when a single building site with multiple wiring closet or multiple building having less than 10,000 endpoints.

These sites are usually have 2 tier Collapsed Core/Distribution and Edge Node.

In this type of design, Collapsed core switches can be uses for both Border node and Control plane node. These Collapsed core are connected to each other with a cross link to provide alternative forwarding path and resiliency.

Because of large number of AP and Endpoints, Physical WLC are deployed to service block switch using Layer 2 port-channels for redundancy. The Service Block switch are small stack switch connected to Collapsed core switches and if DHCP and DNS are site local then the fusion router will also be connected to Service Block switch.

Below is the Design guidelines mentioned below