Hi, Yes, bgapi helps to solve the ESL issue. ESL does not block any more. However, the Channel still blocks when trying to leave the conference. During FreeSWITCH shutdown, the following issue is logged: 2017-10-09 09:42:51.115212 [NOTICE] switch_loadable_module.c:1055 Deleting Application 'conference' 2017-10-09 09:43:01.134791 [ERR] switch_loadable_module.c:1062 Giving up on 'conference' waiting for existing references. 2017-10-09 09:43:01.134791 [NOTICE] switch_loadable_module.c:1110 Deleting API Function 'conference' 2017-10-09 09:43:11.155363 [ERR] switch_loadable_module.c:1118 Giving up on 'conference' waiting for existing references. Regards, Tobias Hi, since updating from FreeSWITCH 1.6.8 to FreeSWITCH 1.6.17 (Windows Server 2012 R2), the Event Socket Handler(inbound mode) sporadically stops sending Channel related Event Info. Once in this situation, the Event Socket Handler does not recover until either reset of the ESL connection by the Host that established the ESL connection or reload of mod_event_socket. Shortly before Event Socket connection drops it seems that there is a problem trying to close a channel. Example Log for failure case: Channel with uuid d9be476b-6a9d-4c96-95fb-5d8728bcc08e is never closed after leavig the conference. d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:35.399989 [NOTICE] switch_channel.c:1104 New Channel sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> [d9be476b-6a9d-4c96-95fb-5d8728bcc08e] d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:35.399989 [INFO] mod_dialplan_xml.c:637 Processing 149 <149>->4600 in context public d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:35.399989 [NOTICE] switch_ivr.c:2172 Transfer sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> to XML[4600 at default<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>] d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:35.419958 [INFO] mod_dialplan_xml.c:637 Processing 149 <149>->4600 in context default d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:35.439966 [NOTICE] mod_dptools.c:1312 Channel [sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>] has been answered d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:55.940144 [NOTICE] sofia.c:1012 Hangup sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> [CS_EXECUTE] [NORMAL_CLEARING] d9be476b-6a9d-4c96-95fb-5d8728bcc08e 2017-08-29 10:59:55.940144 [INFO] conference_loop.c:1469 Channel leaving conference, cause: NORMAL_CLEARING Example Log for regular case: Channel with uuid 982453be-a321-4825-a944-ecfffa715914 is closed correctly after leaving the conference): 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:55:51.340132 [NOTICE] switch_channel.c:1104 New Channel sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> [982453be-a321-4825-a944-ecfffa715914] 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:55:51.340132 [INFO] mod_dialplan_xml.c:637 Processing 149 <149>->4600 in context public 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:55:51.360126 [NOTICE] switch_ivr.c:2172 Transfer sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> to XML[4600 at default<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>] 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:55:51.360126 [INFO] mod_dialplan_xml.c:637 Processing 149 <149>->4600 in context default 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:55:51.380148 [NOTICE] mod_dptools.c:1312 Channel [sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>] has been answered 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:56:11.900321 [NOTICE] sofia.c:1012 Hangup sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> [CS_EXECUTE] [NORMAL_CLEARING] 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:56:11.900321 [INFO] conference_loop.c:1469 Channel leaving conference, cause: NORMAL_CLEARING 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:56:11.900321 [NOTICE] switch_core_session.c:1683 Session 9744 (sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>) Ended 982453be-a321-4825-a944-ecfffa715914 2017-08-29 10:56:11.900321 [NOTICE] switch_core_session.c:1687 Close Channel sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users> [CS_DESTROY] The channel with uuid d9be476b-6a9d-4c96-95fb-5d8728bcc08e will still be displayed at fs_cli on request of "show channels" freeswitch at 1250-0110<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>> show channels uuid,direction,created,created_epoch,name,state,cid_name,cid_num,ip_addr,dest,application,application_data,dialplan,context,read_codec,read_rate,read_bit_rate,write_codec,write_rate,write_bit_rate,secure,hostname,presence_id,presence_data,accountcode,callstate,callee_name,callee_num,callee_direction,call_uuid,sent_callee_name,sent_callee_num,initial_cid_name,initial_cid_num,initial_ip_addr,initial_dest,initial_dialplan,initial_context d9be476b-6a9d-4c96-95fb-5d8728bcc08e,inbound,2017-08-29 10:59:35,1503997175,sofia/external/149 at dialin<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>,CS_EXECUTE,149,149,dialin,4600,playback,{playBackId=2573}us/announcement.wav,XML,default,L16,8000,128000,PCMA,8000,64000,,1250-0110,,,,ACTIVE,,,,,,,149,149,dialin,4600,XML,public 1 total. However, trying to retrieve the channel data for this channel e.g. "uuid_dump" fails. freeswitch at 1250-0110<http://lists.freeswitch.org/mailman/listinfo/freeswitch-users>> uuid_dump d9be476b-6a9d-4c96-95fb-5d8728bcc08e -ERR No such channel! Same issue exists with FreeSWITCH 1.6.19. We are continuously sending api commands to the channel. Could this be a race condition, receiving an api, while the Channel is trying to close ? Would bgapi help ? Why is it not an issue with FreeSWITCH 1.6.8 ? Regards, Tobias