Merge pull request #217430 from duongau/afdrouting

Azure Front Door - Routing methods (add diagram)

Author: Stacyrch140

articles/frontdoor/media/routing-methods/routing-expanded.png

@@ -41,15 +41,13 @@ All Front Door configurations have backend health monitoring and automated insta
 
 ## <a name = "latency"></a>Lowest latencies based traffic-routing
 
-Deploying origins in two or more locations across the globe can improve the responsiveness of your applications by routing traffic to the destination that is 'closest' to your end users. Latency is the default traffic-routing method for your Front Door configuration. This routing method forwards requests from your end users to the closest origin behind Azure Front Door. This routing mechanism combined with the anycast architecture of Azure Front Door ensures that each of your end users get the best performance based on their location.
+Deploying origins in two or more locations across the globe can improve the responsiveness of your applications by routing traffic to the destination that is 'closest' to your end users. Latency is the default traffic-routing method for your Front Door configuration. This routing method forwards requests from your end users to the closest origin behind Azure Front Door. This routing mechanism combined with the anycast architecture of Azure Front Door ensures that each of your end users gets the best performance based on their location.
 
 The 'closest' origin isn't necessarily closest as measured by geographic distance. Instead, Azure Front Door determines the closest origin by measuring network latency. Read more about [Azure Front Door routing architecture](front-door-routing-architecture.md). 
 
 The following table shows the overall decision flow:
 
-| Available origins | Priority | Latency signal (based on health probe) | Weights |
-|-------------| ----------- | ----------- | ----------- |
-| First, select all origins that are enabled and returned healthy (200 OK) for the health probe. If there are six origins A, B, C, D, E, and F, and among them C is unhealthy and E is disabled. The list of available origins is A, B, D, and F.  | Next, the top priority origins among the available ones are selected. If origin A, B, and D have priority 1 and origin F has a priority of 2. Then, the selected origins will be A, B, and D.| Select the origins with latency range (least latency & latency sensitivity in ms specified). If origin A is 15 ms, B is 30 ms and D is 60 ms away from the Azure Front Door environment where the request landed, and latency sensitivity is 30 ms, then the lowest latency pool consist of origin A and B, because D is beyond 30 ms away from the closest origin that is A. | Lastly, Azure Front Door will round robin the traffic among the final selected group of origins in the ratio of weights specified. For example, if origin A has a weight of 5 and origin B has a weight of 8, then the traffic will be distributed in the ratio of 5:8 among origins A and B. |
+:::image type="content" source="./media/routing-methods/routing.png" alt-text="Diagram explaining how origins are selected based on priority, latency and weight settings in Azure Front Door." lightbox="./media/routing-methods/routing-expanded.png":::
 
 >[!NOTE]
 > By default, the latency sensitivity property is set to 0 ms. With this setting the request is always forwarded to the fastest available origins and weights on the origin don't take effect unless two origins have the same network latency.