Posting this here as it makes no sense to me.
UC500 with latest IOS has FXS port and uses outgoing dial-peer to a trunk group of BRIs.
The FXS port is in basic dial-peer mode, not SCCP mode, calling out one get disconnect tone as the last digits is entered, in traces we can see disconnect code 63 and "Call blocked by CLI - IEC 1.1.228.11.29.0".
Calls from FXS to local ephone-dn work fine.
Calls from ephone using same DP work fine
There is no COR configuration of any sort.
Converted FXS from basic mode to SCCP and it works fine.
Mindboggling.
