intercom extension not ringing

[suthomas1]

Hello,

On a site 4 intercoms are connected at different entry & exit points.These are registered with Call manager via SIP having individual extensions each(eg 1001-1004). The intercoms are then configured to relay inputs on a different extension(2011).

Whenever someone pushes the buttons on these intercoms, it places a call on extension 2011 resulting a ring for that 2011 number. This 2011 is being shared as additional DN's among 2 different staff who also

have their own separate extensions for non-intercom related calls.

It has been seen that some of the intercoms when pressed doesn't result in a ring on extension 2011.

The intercoms all appear registered correctly.

Can someone please help with suggestions on how to check whats happening with no ringing on the 

extension when intercoms are pressed. Any inputs will be greatly appreciated, as this is having major problems at that office.

Thanks in advance.

[Jonathan Schulenberg · Accepted solution]

CUCM Intercom and regular Directory Numbers cannot call one another - they are totally separate. Additionally, intercoms can’t be shared across multiple devices and don’t ring; they always auto-answer with mute enabled.

Can you clarify your configuration based on that? I can’t quite discern what’s an intercom vs. regular DN in your current description.

[suthomas1]

Thanks. These are third party IP based intercoms , but are integrated with our CUCM.
Each intercom has an extension allocated .eg 1001 in cucm which they register to.

Intercoms have a call direct function which directs it to a extension number , whcih is 1002.
The intercom operates in a way that ; when its buzzer is pressed, it sends a ring to 1002.
The relay on/off function in intercom is set to digit 2. Post the ringing when anyone presses
2 on their cisco ip phones, the relay activates & opens up the entry/exit access.
what is this auto-answer about ?

Appreciate all inputs.