Hi, I want to make calls forwarded from GSM gateway to Freeswitch extension When I dial a 10- digit mobile number of a sim configured in the GSM gateway in a way that it forwards the incoming call to freeswitch extension. I do not hear anything except for some background noise Freeswitch codec configuration : <X-PRE-PROCESS cmd="set" data="global_codec_prefs=GSM,PCMU,PCMA"/> <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=GSM,PCMU,PCMA"/> GSM- Gateway Codec settings : priority 1 - G.711 u-law priority 2 - G.711 a-law Dialplan in public context : <include> <extension name="public_did"> <condition field="destination_number" expression="^(9811806537)$"> <action application="transfer" data="5000 XML default"/> </condition> </extension> </include> Freeswitch logs: 2016-06-07 05:10:51.000656 [NOTICE] switch_channel.c:1055 New Channel sofia/external/00919716517818@192.168.20.36:5060 [33e4e958-2c6e-11e6-9af0-278859dd14e6] 2016-06-07 05:10:51.000656 [INFO] mod_dialplan_xml.c:635 Processing 00919716517818 <00919716517818>->9811806537 in context public 2016-06-07 05:10:51.000656 [NOTICE] switch_ivr.c:1861 Transfer sofia/external/00919716517818@192.168.20.36:5060 to XML[5000@default] 2016-06-07 05:10:51.000656 [INFO] mod_dialplan_xml.c:635 Processing 00919716517818 <00919716517818>->5000 in context default 2016-06-07 05:10:51.000656 [NOTICE] sofia_media.c:92 Pre-Answer sofia/external/00919716517818@192.168.20.36:5060! 2016-06-07 05:10:51.000656 [NOTICE] mod_dptools.c:1268 Channel [sofia/external/00919716517818@192.168.20.36:5060] has been answered 2016-06-07 05:10:51.640675 [INFO] switch_rtp.c:5846 Auto Changing port from 192.168.20.36:31012 to 103.25.231.101:31012 2016-06-07 05:11:06.560680 [NOTICE] sofia.c:952 Hangup sofia/external/ 00919716517818@192.168.20.36:5060 [CS_EXECUTE] [NORMAL_CLEARING] 2016-06-07 05:11:06.560680 [NOTICE] switch_core_session.c:1641 Session 262 (sofia/external/00919716517818@192.168.20.36:5060) Ended 2016-06-07 05:11:06.560680 [NOTICE] switch_core_session.c:1645 Close Channel sofia/external/00919716517818@192.168.20.36:5060 [CS_DESTROY] Regards, Deepika