My customer has 3 analog conference stations
ClearOne Max EX wired
Polycom Voicestation 300
Polycom Soundstation VTX 1000
These are connected to a VG224, added to the CUCM. for conferencing, Users should ideally place the first call on hold and then dial the 3rd number and conference. Users are unable to place the first call on hold and then dial a second number and then put the two dialled calls in conference.
Please provide some suggestions to troubleshoot this.