This is a fully supported mode. See:

From: app_rpt-users-bounces@ohnosec.org [mailto:app_rpt-users-bounces@ohnosec.org] On Behalf Of Robert
Sent: Friday, July 11, 2014 12:24 PM
To: 'app_rpt mailing list'
Subject: [App_rpt-users] Allstar and External controllers

A question.

If Allstar is not being used in a voted configuration why can’t I connect external controllers to my repeaters’ and then Allstar to port 1 of the external controller? This would then let me run my parallel backup links in case the internet goes down.

Thank you in advance.