We are in stage to configure SIP trunk to ITSP from ISR 4331 gateway, I have added following configuration, but SIP-UA registration status is showing as "no".
Call flow:
CUCM >> SIP >> Gig 0/0/0 >> ISR 4431 gateway >> Gig 0/0/1 >> SIP >> ITSP.
...
I had the same issue, made following changes and got the second line registered.
1. Updated TFTP server IP address on ATA190 web administration ( Voice -> Provisioning) page.
2.Added another ATA190 with shifted mac address.
Ex: MAC address of ATA190...
