Hello Alexander, Thank you for the reply and the suggestion. Setting the CUE transfer to "blind bye-also" and disabling h450. services on the router was indeed the correct combination of settings to get the audio running with this script. Below are the settings in the "voice service voip" for anyone who might run into similar issues: voice service voip no ip address trusted authenticate ip address trusted call-block cause call-reject no lpcor incoming voice call rate monitor no notify redirect ip2ip no callmonitor no rtcp keepalive rtp-port range 0 0 no rtp-ssrc multiplex no dtmf-interworking cpa cpa timing silent 375 cpa timing live-person 2500 cpa timing timeout 3000 cpa timing noise-period 100 cpa timing valid-speech 112 cpa timing term-tone 15000 cpa threshold noise-level max -50dBm0 cpa threshold noise-level min -60dBm0 cpa threshold active-signal 15db no mode border-element media flow-through cti timeout make-call-prompt 60 cti shutdown allow-connections sip to sip no redundancy no supplementary-service h450.2 no supplementary-service h450.3 no supplementary-service h450.7 no supplementary-service h450.12 advertise-only no supplementary-service h450.12 no supplementary-service h225-notify cid-update supplementary-service sip moved-temporarily no supplementary-service sip refer supplementary-service sip handle-replaces no supplementary-service media-renegotiate no supplementary-service ringback h225-info redirect ip2ip text relay modulation baudot45.45 autobaud-on fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback none fax-relay sg3-to-g3   no cause-code legacy modem relay latency 200 modem relay gateway-xid dictionary 1024 string-length 32 compress backward modem relay sse redundancy interval 20 modem relay sse redundancy packet 3 modem relay sse t1 1000 modem relay sse retries 3 modem relay sprt retries 12 modem relay sprt v14 receive playback hold-time 50 modem relay sprt v14 transmit hold-time 20 modem relay sprt v14 transmit maximum hold-count 16 ... View more