You may need a bell on a Cisco phone if for example you have a phone in a office and say a bell in a corridor or something like that.
This turned out to be quite a challenging issue, on a standard analogue PABX system it is quite easy to make a bell ring, you simply connect it in line with the phone and it works. If you want a bell to work on a Cisco IP system it’s not that simple.
So the solution is as follows, lets say you have a Cisco IP phone with a extension number of 4567 what you need to do is set a ATA up (I used a Cisco ATA 186, but I guess others will work also) and assign the same number to the ATA as you have the phone. Then, assuming you are on structured data cables, and keep the ATA in the comms cabinet, I connected a RJ11 to RJ45 cross over from the ATA RJ45 to the RJ45 on the patch rail, then from the room where the bell needed to be I connected a PABX Master from the RJ45 wall port and connected the bell to that and it works !.
One thing to note is that if the phone that has the bell is in a pickup group, the bell keeps ring when other calls come in, so best to not have it in a pickup group or if you do, don’t make it a audible pickup group.