The remove_header message is not an error.
“All circuits busy now” is practically any failure for a call that gets as far as trying to call the destination, so is of no use without detailed logging. Please look at recent threads, for examples of how to debug this.
Typical causes, are:
- failure confirm connectivity (qualify);
- authentication failure;
- unacceptable called number format;
- unacceptable caller ID;
- you’ve exceeded your contracted number of simultaneous calls;
- the provider’s network has too many concurrent calls.