Added aspera firewall info and updated plugin install steps

external/exchange-channels/duma.md

@@ -3,7 +3,16 @@
 {:toc}
 
 ## Overview
-AsperaWEB is an IBM Aspera deployment at the LCSB-University of Luxembourg. AsperaWEB supports end-to-end encrypted data transfer and can handle high data volumes e.g. several tera bytes.
+AsperaWEB is an IBM Aspera deployment at the LCSB-University of Luxembourg. AsperaWEB supports end-to-end encrypted data transfer and can handle high data volumes e.g. several tera bytes.z
+
+> **IMPORTANT NOTE:** Aspera requires UDP ports to be enabled on firewalls. 
+
+Specifically your firewall should:
+ * Allow outbound connections from the Aspera client on the TCP port (TCP/33001, by default, when connecting to a Windows server, or on another non-default port for other server operating systems).
+ * Allow outbound connections from the Aspera client on the fasp UDP port (33001, by default).
+ * If you have a local firewall on your server (like Windows Firewall), verify that it is not blocking your SSH and fasp transfer ports (e.g. TCP/UDP 33001).
+
+Detailed information on how to configure firewalls when working with Aspera is given [here](https://download.asperasoft.com/download/docs/p2p/3.5.1/p2p_admin_win/webhelp/dita/configuring_the_firewall.html).
 
 ## Obtaining a AsperaWEB access link
 
@@ -35,7 +44,9 @@ In the following steps we provide instructions on how to use AsperaWEB web inter
 
 	* close the installer, the Aspera Connect should try to open - *depending on your Operating System you may be asked if you are sure to open it* -
 
-	* the prompt should disapears
+	* the prompt should disappear
+	
+	* restart your browser
 
 
 3. The **access link** page will display a **File Browser** section. Depending on the settings per access link, users can create or delete folders in the File Browser and upload and/or download data.<br/>