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This was on by default on a consumer router that was used at a small office. Their VoIP phones would get phantom calls until I discovered this and disabled it.
by jasonjayr 3y ago
This was on by default on a consumer router that was used at a small office. Their VoIP phones would get phantom calls until I discovered this and disabled it.
- hashstring 3y agoWoah, good find. How did you actually find out that this was happening? Network captures? When was this approximately? I’m wondering how widespread this (still) is.
- jasonjayr 3y agoIt would have been 2-3 years ago. I was getting reports of phones ringing, but no audio, no calls record from the VoIP server CDR (which all phones were configured to proxy through) and when looking @ the system logs from the phones, they were reporting nonsensical IP addresses, which pointed to something at the edge of the network.
- jeroenhd 3y agoI'm pretty sure you've solved a mystery I was confused by years ago, back when I was doing tech support. It wouldn't have mattered much because the router/modem combos in use didn't have a switch for SIP ALG anyway, bit it's good router finally know what could've caused the phantom phone ringing.