Forum Discussion
UDP port 4021 tmobile VS my alarm server...
It is unlikely the T-Mobile is blocking at the network level so it would be related to the router itself. The Envisalink uses UDP port 4021 for communication so the router is blocking that port, po...
I also check the needed 4021 on both properties and it is shown closed… Any idea on how to get it open.. Tmobile tech is like talking to a rock ….. they have no idea what I am asking
