Unable to hear caller after hold

My company uses Grandstream GXV3275 VoIP phones. Sometimes when taking a call off hold, it’s as if the person on the other end of the line has us on mute. The only fix I’ve found is to hang up and call again. The following message appears in the phones’ syslog every time the problem occurs:

GXV3275: GS_AVS SRTPTransfer srtp unprotection rtp failed with code 7
GXV3275: GS_AVS RTPTransport srtp decrypt rtp failed

I assume we’re having some problem renegotiating SRTP with external callers. I have encryption = yes set in /etc/asterisk/users.conf and SRTP is set to “Enabled but not forced” in the phone config. Any ideas what might be causing this? Do you think it’s a problem with the phones or my asterisk config?

Which exact version of Asterisk, as I half remmber this as a fixed problem.

There were problems within Asterisk with SRTP renegotiation but with a recent libsrtp (minimum 1.5.4) there are no known problems that I’m aware of. That doesn’t cover endpoints though. Some don’t properly handle the renegotiation after going off hold and use different keys then they should, causing decryption failure.

1 Like

I’m running Asterisk 14.7.6 and libsrtp0 1.4.5 (the latest version of libsrtp in Debian Stretch as far as I know).

Your version of Asterisk is no longer supported, and your version of libsrtp is older than the one we require these days (due to reasons such as what you are experiencing).

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.