1 T1PRI connected to vendor for incoming and outgoing calls.
9.@ as normal route pattern for outgoing calls.
44001.!# is test route pattern for T1PRI line;
The issue is, when dial 9011xxxxxxx to make international call, it failed with fast busy tone. When using 44001 011xxxxxxx# to test, it works which means no issue on the vendor side.
Both 9.@ and 44001.!# are configured as below:
Numbering Plan: North American Numbering Plan
Gateway or Route List: PSTN
Route Option Route this pattern
Which others do I need to check?