Phones which use caller ID to set the time?

This might be more of an ATA thing than a FreePBX thing but asking anyway…

My Panasonic cordless handsets use the caller ID timestamp to set the time. It works very well. Or, it did, until I disconnected my phones from the PSTN and connected them to FreePBX/Asterisk and a Linksys SPA3000.

Now despite the fact caller ID works beautifully, they no longer ‘inherit’ the time from the data packet.

Any ideas??



I’d honestly never heard of such a thing until just this second, so I checked out the Panasonic forums, and low and behold, this is apparently a real thing. There is no explanation of how it’s supposed to work, only that you should turn it off when it doesn’t.

Take me out back and paint me purple.


@cynjut, this is how pretty much all PSTN-ready phones with CID set their system date/time back in the “good ol’ days.”

That said, PSTN CID is different from SIP CID in a few key ways: PSTN CID is typically transmitted between the first and second ring of an incoming call, while SIP CID is transmitted in the initial INVITE packet at the very beginning, for starters.

@dan_ce, there is an option in most Cisco/Linksys SPAs called “PSTN CID For VoIP CID” or something to that effect. You may want to toggle that option to see if it resolves your issue. While it is normally intended while using the ATA to bring incoming PSTN CID into a PBX, it may also be coded to alter something when used in the other direction.

Does the Info page on your SPA under System Status show Current Time correctly? If not, fix your NTP settings.

If that’s not it, see whether Asterisk is sending a Date header when calling the SPA.

It’s showing the correct time, NTP is

Is this something I’d check using a syslog sever, by looking at the Asterisk logs or by using wireshark? The problem I’ve had with wireshark is because I’m on WiFi on a laptop I don’t think I can capture packets travelling over ethernet.

So i guess its totally up to the ATA to fill in the blanks.

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