Unreachable trunks Vs. Ports changiung

[size=150]my iax trunks between 2 or more TBs goes unreachable from time to time
i changed qualify to qualify = 4000
there is no firewall so the NAT settings changes won’t be useful
the solution i have is changing the ports manually in the trunk settings
1- is there any other solution ?
2- what is the relation between changing the ports and the trunks state??
3- can i add more than 1 port so the trunks check for all of the working one ???[/size]

Do you believe this is an Asterisk specific problem? Did you post this also on the Trixbox forums?

yes i did
but it seems that no one knows an answer there
thats why i came to ask here