updated steps for creating a relay namespace

articles/service-bus-relay/relay-wcf-dotnet-get-started.md

@@ -34,7 +34,10 @@ access these services at a fine-grained level. It provides a powerful and secure
 
 This article discusses how to use Azure Relay to create a WCF web service, exposed using a TCP channel binding, that implements a secure conversation between two parties.
 
-[!INCLUDE [service-bus-create-namespace-portal](../../includes/service-bus-create-namespace-portal.md)]
+## Create a Relay namespace
+The first step is to create a namespace, and to obtain a [Shared Access Signature (SAS)](../service-bus-messaging/service-bus-sas.md) key. A namespace provides an application boundary for each application exposed through the relay service. A SAS key is automatically generated by the system when a service namespace is created. The combination of service namespace and SAS key provides the credentials for Azure to authenticate access to an application.
+
+[!INCLUDE [relay-create-namespace-portal](../../includes/relay-create-namespace-portal.md)]
 
 ## Get the Service Bus NuGet package
 The [Service Bus NuGet package](https://www.nuget.org/packages/WindowsAzure.ServiceBus) is the easiest way to get the Service Bus API and to configure your application with all of the Service Bus dependencies. To install the NuGet package in your project, do the following: