GXW4108 does not pass hook flash to PSTN



I have GXW4108 (latest sw version, FXO ports). I am trying to sort out the hook flash (for the GW to pass it from the SIP trunk to PSTN analogue line).

One of the old release notes state- “Added support for regeneration of hook flash event upon receiving event from VoIP side via SIN INFO or RFC2833”

I would like to send DTMF 16 out of band with RFC2833 indicating in the telephony events 0-16 in the INVITE SDP to the GW. However the GW respond with 0-11.

Could anyone please let me know if this can be changed/configured somewhere on the GW.



What is sending the DTMF?


The DTMF is sent by a voip phone as out of band telephony events (RFC2833)


And using Wireshark you have confirmed the phone sends Event 16?


Yes, but my main question is why the GW puts 101 0-11 in the SDP rather than 0-16


Cannot answer that. You will need to submit a ticket to the help desk and include the pcap file showing that the phone is indeed sending the Event 16.