document transcoding limits

Author: nslack

articles/communications-gateway/includes/communications-gateway-general-restrictions.md

@@ -10,4 +10,5 @@ The following restrictions apply to all Azure Communications Gateways:
 
 * All traffic must use IPv4.
 * All traffic must use TLS 1.2 or greater. Earlier versions aren't supported.
-* The number of active calls is limited to 15% of the number of users assigned to Azure Communications Gateway. For the definition of users, see [Plan and manage costs for Azure Communications Gateway](/azure/communications-gateway/plan-and-manage-costs).
+* The number of active calls is limited to 15% of the number of users assigned to Azure Communications Gateway. For the definition of users, see [Plan and manage costs for Azure Communications Gateway](/azure/communications-gateway/plan-and-manage-costs).
+* The number of calls being actively transcoded is limited to 5% of the total number of active calls.