| Unfortunately, there are a lot of things that could be causing this. I would start by looking at logs on both sides. Do you have the ability to see in a log the connection being established, or better yet, any error messages that are being shown when the connection doesn't go through?
Things to look for:
Who is playing the busy signal? Asterisk/Local or skip2pbx/Remote.
Are you using SIP for the trunk?
Is either server directly on the internet? (Sip doesn't like to be doubled NAT'd behind firewalls)
Do you see the trunk connection being registered on both sides? |