Sangoma S500 keysets, freepbx V13 mini appliance, Vega60 gateway with 3 analog trunks (2V, 1Fax)
When a call comes in, and they answer during the 2nd ring or so, they will frequently hear a pulsing noise. The closest description I can think of is the sound you’d get if you had a buttset connected to an analog line and it rang.
Updated the firmware on the Vega, getting ready to update freepbx to the latest version, but I’d like to know what’s causing this if possible.
bt is probably BT, i.e. British Telecom, which does a line reversal and a handshake before the first ring. Everywhere else tends to send the CID between first and second ring, so, if you don’t have things set to delay the presentation of ringing until after the second ring, you could answer whilst the caller ID is being sent. If you use BT rules and there is no initial line reversal, it may well report anonymous.
I would assume that ETSI-FSK assumes V.23 tones, but the US uses Bell tones.
You want the appropriate one of the GR30- ones for North America. It would appear that ETSI-FSK expect the caller ID before the first ring, so would be expected to present Ringing before a US central office started sending caller ID.
Using the GR30 fixed the problem with Anonymous and caller ID info is now sent. I’ll have to pop into the office tomorrow to check the audio quality, but I feel confident that has fixed this portion of the problem.