I have two CME systems connected using a SIP trunk. In both systems, SCCP was used as a signaling protocol. In that situation all works properly. Then, all phones in one site are converted to SIP. Local calls on this site work properly, but calls across the SIP trunk don't work. When calling from SIP side to SCCP side, a reorder tone is heard. When calling from SCCP side to SIP side, the phone at the SIP side rings but no voice is heard.
Any idea about how to solve it?