This one has been driving me crazy. I use PhoneTray, which works in conjunction with a modem and caller ID to screen telephone calls against a database of telemarketers and automatically reject calls from numbers on the list. It has worked for the past several years with my Hiro H50003 internal fax modem that does support caller ID. I am aware of the correct modem command to report caller ID (AT+VCID=1) , and yes, it is enabled.
My phone service is via VOIP, and yes, it also supports caller ID. I have several phones in the house, as well as a separate caller ID box that report the Caller ID correctly. A few months ago the VOIP provider upgraded the VOIP adapter to a new model. The problems with my fax modem reporting caller ID seemed to start occurring after that. Initially it would intermittently fail to report the caller ID to PhoneTray perhaps 20 percent of the time. Over a period of a couple of months that has increased to 100 percent.
I tried swapping the modem (to another Hiro 50003), and that doesn't make any difference. I have unloaded PhoneTray and tested the fax modem with HyperTerminal on incoming calls; it's still no longer reporting the caller ID, even though other phones in the house and the external caller ID box continue to have no problem. I contacted PhoneTray and they are as baffled by this problem as I am.
I'm beginning to wonder if it's an issue with the level of the signal the modem is receiving: it may not be high enough to trigger caller ID. I can think of no way to measure this, however, and is there any way to increase the signal level?
Am I barking up the wrong tree, or is there another potential solution I may be unaware of or ignoring? Any assistance would be appreciated.