fpignataro Me ha funcionado ,
Ahora tengo este problema con el codec GSM
-- Executing [s@sub-oml-set-chanvars:26] ExecIf("SIP/PBXDEMO-00000003", "1?Set(__OMLUNIQUEID=1644354685.6)") in new stack
    -- Executing [s@sub-oml-set-chanvars:27] Return("SIP/PBXDEMO-00000003", "") in new stack
    -- Executing [43754205@from-pstn:5] GotoIf("SIP/PBXDEMO-00000003", "0?inrOk") in new stack
    -- Executing [43754205@from-pstn:6] Playback("SIP/PBXDEMO-00000003", "pbx-invalid") in new stack
       > 0x7f4b7c014d60 -- Strict RTP switching to RTP target address 192.168.120.26:12154 as source
[Feb  8 16:11:25] WARNING[20483][C-00000004]: channel.c:5694 set_format: Unable to find a codec translation path: (gsm) -> (alaw)
[Feb  8 16:11:25] WARNING[20483][C-00000004]: file.c:1262 ast_streamfile: Unable to open pbx-invalid (format (alaw)): No such file or                                            directory
[Feb  8 16:11:25] WARNING[20483][C-00000004]: app_playback.c:497 playback_exec: Playback failed on SIP/PBXDEMO-00000003 for pbx-inval                                           id
    -- Executing [43754205@from-pstn:7] Gosub("SIP/PBXDEMO-00000003", "sub-oml-hangup,s,1(IN-R fail)") in new stack
    -- Executing [s@sub-oml-hangup:1] Verbose("SIP/PBXDEMO-00000003", "2, Hangup call") in new stack
  ==  Hangup call
    -- Executing [s@sub-oml-hangup:2] Verbose("SIP/PBXDEMO-00000003", "2, Todo fue un fugaz pensamiento en la mente del TODO") in new                                            stack
  ==  Todo fue un fugaz pensamiento en la mente del TODO
    -- Executing [s@sub-oml-hangup:3] Verbose("SIP/PBXDEMO-00000003", "2, IN-R fail") in new stack
  ==  IN-R fail
hice un core show translation paths gsm
--- Translation paths SRC Codec "gsm" sample rate 8000 ---
        gsm:8000         To codec2:8000     : No Translation Path
        gsm:8000         To g723:8000       : No Translation Path
        gsm:8000         To ulaw:8000       : No Translation Path
        gsm:8000         To alaw:8000       : No Translation Path
        gsm:8000         To g726:8000       : No Translation Path
        gsm:8000         To g726aal2:8000   : No Translation Path
        gsm:8000         To adpcm:8000      : No Translation Path
        gsm:8000         To slin:8000       : No Translation Path
        gsm:8000         To slin:12000      : No Translation Path
        gsm:8000         To slin:16000      : No Translation Path
        gsm:8000         To slin:24000      : No Translation Path
        gsm:8000         To slin:32000      : No Translation Path
        gsm:8000         To slin:44100      : No Translation Path
        gsm:8000         To slin:48000      : No Translation Path
        gsm:8000         To slin:96000      : No Translation Path
        gsm:8000         To slin:192000     : No Translation Path
        gsm:8000         To lpc10:8000      : No Translation Path
        gsm:8000         To g729:8000       : No Translation Path
        gsm:8000         To speex:8000      : No Translation Path
        gsm:8000         To speex:16000     : No Translation Path
        gsm:8000         To speex:32000     : No Translation Path
        gsm:8000         To ilbc:8000       : No Translation Path
        gsm:8000         To g722:16000      : No Translation Path
        gsm:8000         To siren7:16000    : No Translation Path
        gsm:8000         To siren14:32000   : No Translation Path
        gsm:8000         To testlaw:8000    : No Translation Path
        gsm:8000         To g719:48000      : No Translation Path
        gsm:8000         To opus:48000      : No Translation Path
        gsm:8000         To none:8000       : No Translation Path
        gsm:8000         To silk:8000       : No Translation Path
        gsm:8000         To silk:12000      : No Translation Path
        gsm:8000         To silk:16000      : No Translation Path
        gsm:8000         To silk:24000      : No Translation Path