CISCO 7912 does not return 486 busy signal

[chrisazzi]

Hello Experts,

i have just moved 50 cisco 7912 phones over from SCCP to SIP and for some strange reason they wont return a 486 busy signal when they are in use. this is causing us problems with going to voicemail. we have plenty of 7940 which are working perfectly.

Can you please shed some light on wherei should be looking to enable this signal?

thanks In advance.

chris

[Steven Holl]

Is this CME or CUCM?  What version of firmware are you running?  What do you have set on the DN for max calls/busy trigger (if CUCM) or on the ephone-dn (for CME)?