[asterisk-users] Grandstream HT 503 Outoing 403 Forbidden

[Jim Rosenberg]

I am trying to get Asterisk 1.6.2.5 working with a Grandstream HT-503 ATA. 
The FXO part is giving me fits. Every call I try to make to the FXO port 
outbound I get 403 Forbidden coming back. I've been through every 
configuration setting I can see, and Uncle Google is not helping me much. I 
updated the firmware to the current version, and that didn't help.

If anyone has this working, I would like to know the secret sauce.

-Thanks, Jim