Cisco cucm 12.5 conference between 3 phones not working

[Juraj Papic]

Hello,

I have a cucm 12.5 and when I try to have a call between 3 phones the calls drops down.

Thanks. 

[mavked]

what types of phones ?

what happens exactly ? just call drop or fast busy something?

do the phones have a conference bridge ressource configured?

[George Sotiropoulos]

Hello Juraj,

You should first of all check on the CUCM Admin Page->Media Resources->Conference Bridge and confirm that the status is "Registered"

Then you should check on your phone if it is on the correct Media Resource Group.

I hope this helps,

George