UCM6302a caller id not working


PSA, caller id on the ucm6302 is hit or miss on analog Fxo ports. beware.
yes, we have tested with a regular pots phone and a ucm6202, they both recognize the caller id, but the 6302 doesnt, yes we have an open ticket with help desk. yes, its painful. they send the wrong instructions for what they want done… is there paid support somewhere?


Plenty of Grandstream trained guys on here to be hired and assist from your country.


I’ve had issues with analog caller ID at some sites - and the issues ranged from caller ID being intermittent to the trunk port on the system stops working completely.
Have you checked the loop current and voltage? If your site is quite close to the central office, the loop current might be higher than the system is designed to manage, and Caller ID is sometimes distorted to the point of unrecognizable when this happens. The sweet spot is between 25mA and 50mA. Loop current outside this goldilox zone can make caller ID misbehave and it could be dangerous if its over 80mA (meaning the trunk port could be permanently damaged).
Loop Current & Circuit Loss Technical Bulletin (sandman.com)

#TOH7O - Loop Current Tester (sandman.com)


What I suggest is raising the FXO port (line) impedance to its maximum value 900 Ohms, and then see if the issue persists, then try with 600 …

The settings are under PBX > Interface settings.

The issue is mostly related to the noise on the line. YOu can confirm this by capturing an analog trace from the UCM62 then the UCM63 while connecting the same line.


for now, we put the ucm6202 back in(works), waiting on a replacement 6302. The analog trace doesnt show anything out of the ordinary on either box. helpdesk says they can see the caller id in the traces, but it doenst show up at the system or on the phones. Hopefully its just hardware that was made on a friday afternoon

all helpdesk had for help was the interface checks and raise the db level to +12.