Updating Overview page

fixing wording and adding a few links

Author: winthrop28

articles/application-gateway/overview.md

@@ -31,7 +31,7 @@ Application gateway supports SSL/TLS termination at the gateway, after which tra
 
 ## Autoscaling
 
-Application Gateway or WAF deployments under Standard_v2 or WAF_v2 SKU support autoscaling and can scale up or down based on changing traffic load patterns. Autoscaling also removes the requirement to choose a deployment size or instance count during provisioning. For more information about the Application Gateway standard_v2 and WAF_v2  features, see [Autoscaling v2 SKU](application-gateway-autoscaling-zone-redundant.md).
+Application Gateway or WAF deployments under Standard_v2 or WAF_v2 SKU support autoscaling and can scale up or down based on changing traffic load patterns. Autoscaling also removes the requirement to choose a deployment size or instance count during provisioning. For more information about the Application Gateway Standard_v2 and WAF_v2  features, see [Autoscaling v2 SKU](application-gateway-autoscaling-zone-redundant.md).
 
 ## Zone redundancy
 
@@ -43,11 +43,11 @@ The application gateway VIP on Standard_v2 or WAF_v2 SKU supports static VIP typ
 
 ## Web application firewall
 
-Web application firewall (WAF) is a feature of Application Gateway that provides centralized protection of your web applications from common exploits and vulnerabilities. WAF is based on rules from the [OWASP (Open Web Application Security Project) core rule sets](https://www.owasp.org/index.php/Category:OWASP_ModSecurity_Core_Rule_Set_Project) 3.0 or 2.2.9. 
+Web application firewall (WAF) is a feature of Application Gateway that provides centralized protection of your web applications from common exploits and vulnerabilities. WAF is based on rules from the [OWASP (Open Web Application Security Project) core rule sets](https://www.owasp.org/index.php/Category:OWASP_ModSecurity_Core_Rule_Set_Project) 3.1 (WAF_v2 only), 3.0, and 2.2.9. 
 
 Web applications are increasingly targets of malicious attacks that exploit common known vulnerabilities. Common among these exploits are SQL injection attacks, cross site scripting attacks to name a few. Preventing such attacks in application code can be challenging and may require rigorous maintenance, patching and monitoring at many layers of the application topology. A centralized web application firewall helps make security management much simpler and gives better assurance to application administrators against threats or intrusions. A WAF solution can also react to a security threat faster by patching a known vulnerability at a central location versus securing each of individual web applications. Existing application gateways can be converted to a web application firewall enabled application gateway easily.
 
-For more information, see [Web application firewall (WAF) in Application Gateway](https://docs.microsoft.com/azure/application-gateway/waf-overview)).
+For more information, see [Web application firewall (WAF) in Application Gateway](https://docs.microsoft.com/azure/application-gateway/waf-overview).
 
 ## URL-based routing
 
@@ -60,7 +60,7 @@ For more information, see [URL-based routing with Application Gateway](https://d
 
 ## Multiple-site hosting
 
-Multiple-site hosting enables you to configure more than one web site on the same application gateway instance. This feature allows you to configure a more efficient topology for your deployments by adding up to 100 web sites to one application gateway. Each web site can be directed to its own pool. For example, application gateway can serve traffic for `contoso.com` and `fabrikam.com` from two server pools called ContosoServerPool and FabrikamServerPool.
+Multiple-site hosting enables you to configure more than one web site on the same application gateway instance. This feature allows you to configure a more efficient topology for your deployments by adding up to 100 web sites to one Application Gateway, or 40 for WAF (for optimal performance). Each web site can be directed to its own pool. For example, application gateway can serve traffic for `contoso.com` and `fabrikam.com` from two server pools called ContosoServerPool and FabrikamServerPool.
 
 Requests for `http://contoso.com` are routed to ContosoServerPool, and `http://fabrikam.com` are routed to FabrikamServerPool.
 
@@ -104,6 +104,8 @@ For more information, see [Azure Application Gateway Ingress Controller](https:/
 
 Connection draining helps you achieve graceful removal of backend pool members during planned service updates. This setting is enabled via the backend http setting and can be applied to all members of a backend pool during rule creation. Once enabled, Application Gateway ensures all de-registering instances of a backend pool do not receive any new request while allowing existing requests to complete within a configured time limit. This applies to both backend instances that are explicitly removed from the backend pool by an API call, and backend instances that are reported as unhealthy as determined by the health probes.
 
+For more information, see the Connection Draining section of [Application Gateway Configuration Overview](https://docs.microsoft.com/azure/application-gateway/configuration-overview#connection-draining).
+
 ## Custom error pages
 
 Application Gateway allows you to create custom error pages instead of displaying default error pages. You can use your own branding and layout using a custom error page.
@@ -124,13 +126,13 @@ For more information, see [Rewrite HTTP headers](rewrite-http-headers.md).
 
 ## Sizing
 
-Application Gateway Standard_v2 and WAF_v2 SKU can be configured for autoscaling or fixed size deployments. These SKUs don't offer different instance sizes.
+Application Gateway Standard_v2 and WAF_v2 SKU can be configured for autoscaling or fixed size deployments. These SKUs don't offer different instance sizes. For more information on v2 performance and pricing, see [Autoscaling v2 SKU](https://docs.microsoft.com/azure/application-gateway/application-gateway-autoscaling-zone-redundant#pricing).
 
 The Application Gateway Standard and WAF SKU is currently offered in three sizes: **Small**, **Medium**, and **Large**. Small instance sizes are intended for development and testing scenarios.
 
 For a complete list of application gateway limits, see [Application Gateway service limits](../azure-subscription-service-limits.md?toc=%2fazure%2fapplication-gateway%2ftoc.json#application-gateway-limits).
 
-The following table shows an average performance throughput for each application gateway instance with SSL offload enabled:
+The following table shows an average performance throughput for each application gateway v1 instance with SSL offload enabled:
 
 | Average back-end page response size | Small | Medium | Large |
 | --- | --- | --- | --- |