Codecs on SIP phones Yealink T31P Grandstream GRP-2602P Cisco SPA-303 Linphone Versions FW  124.86.0.40 HW  123.1.1.0.2.0.0 Boot  1.0.1.32 Core  1.0.5.17 Prog  1.0.5.5 Locale  1.0.5.40 Res  1.0.5.1 in order of priority Opus G722 PCMA PCMU   legacy: G729AB G729 G726/40 kbps G726/32 kbps G726/24 kbps G726/16 kbps iLBC/15.2 kbps iLBC/13.3 kbps G723.1/63 kbps G723.1/53 kbps     Opus G722 PCMA PCMU   legacy: G.729A/B   G.726-40 kbps G.726-32 kbps G.726-24 kbps G.726-16 kbps iLBC   G.723.1 kbps Opus/48 kHz Speex/16 kHz PCMU/8 kHz PCMA/8 kHz GSM/8 kHz G722/8 kHz iLBC/8 kHz G729/8 kHz iSAC/16 kHz speex/32kHz BV16/8 kHz L16/44.1 kHz   (priority order can not be defined in the UI)   ! not supported: G.726 (legacy) G.723 (legacy)