我建了一个 Freeswitch 内核研究 交流群， 45211986， 欢迎加入, 另外，提供基于SIP的通信服务器及客户端解决方案。

freeswitch有大量通道变量挂载在每一路通话中，这些变量的值控制了本路通话的大多行为。

下面根据类型分类的通道变量，慢慢翻译。。。

• ​ ​1 Introduction​ ​

• ​ ​1.1 Channel Variables in the XML Dialplan​ ​

• ​ ​1.1.1 Scoped Variables​ ​

• ​ ​1.2 Channel Variables in Dial strings​ ​

• ​ ​1.2.1 Handling Variables With Commas​ ​

• ​ ​1.3 Exporting Channel Variables in Bridge Operations​ ​
• ​ ​1.4 Using Channel Variables in Dialplan Condition Statements​ ​
• ​ ​1.5 Custom Channel Variables​ ​
• ​ ​1.6 Channel Variable Manipulation​ ​

• ​ ​2 Info Application Variable Names (variable_xxxx)​ ​
• ​ ​3 ${variable} vs. $${variable}​ ​
• ​ ​4 CDR related​ ​

• ​ ​4.1 process_cdr​ ​
• ​ ​4.2 accountcode​ ​
• ​ ​4.3 hangup_complete_with_xml​ ​

• ​ ​5 Hangup Causes​ ​

• ​ ​5.1 bridge_hangup_cause​ ​
• ​ ​5.2 disable_q850_reason​ ​
• ​ ​5.3 hangup_cause​ ​
• ​ ​5.4 hangup_cause_q850​ ​
• ​ ​5.5 sip_hangup_disposition​ ​
• ​ ​5.6 proto_specific_hangup_cause​ ​

• ​ ​6 DTMF Related​ ​

• ​ ​6.1 pass_rfc2833​ ​
• ​ ​6.2 dtmf_type​ ​

• ​ ​7 Media Handling​ ​

• ​ ​7.1 monitor_early_media_fail​ ​
• ​ ​7.2 monitor_early_media_ring​ ​

• ​ ​8 Timeout Related​ ​

• ​ ​8.1 call_timeout​ ​
• ​ ​8.2 leg_timeout​ ​
• ​ ​8.3 originate_continue_on_timeout​ ​
• ​ ​8.4 park_timeout​ ​

• ​ ​9 Music On Hold Related​ ​

• ​ ​9.1 hold_music​ ​
• ​ ​9.2 temp_hold_music​ ​

• ​ ​10 Locale Related​ ​

• ​ ​10.1 default_language​ ​
• ​ ​10.2 timezone​ ​

• ​ ​11 Bridge Related​ ​

• ​ ​11.1 api_after_bridge​ ​
• ​ ​11.2 auto_hunt​ ​
• ​ ​11.3 bridge_early_media​ ​
• ​ ​11.4 bridge_terminate_key​ ​
• ​ ​11.5 continue_on_fail​ ​
• ​ ​11.6 transfer_on_fail​ ​
• ​ ​11.7 enable_file_write_buffering​ ​
• ​ ​11.8 failure_causes​ ​
• ​ ​11.9 force_transfer_context​ ​
• ​ ​11.10 force_transfer_dialplan​ ​
• ​ ​11.11 hangup_after_bridge​ ​
• ​ ​11.12 hold_hangup_xfer_exten​ ​
• ​ ​11.13 last_bridge_to​ ​
• ​ ​11.14 loopback_bowout_on_execute​ ​
• ​ ​11.15 outbound_redirect_fatal​ ​
• ​ ​11.16 originate_timeout​ ​
• ​ ​11.17 park_after_bridge​ ​
• ​ ​11.18 signal_bond​ ​
• ​ ​11.19 sip_jitter_buffer_during_bridge​ ​
• ​ ​11.20 uuid_bridge_continue_on_cancel​ ​

• ​ ​12 Conference Related​ ​

• ​ ​12.1 conference_auto_outcall_announce​ ​
• ​ ​12.2 conference_auto_outcall_caller_id_name​ ​
• ​ ​12.3 conference_auto_outcall_caller_id_number​ ​
• ​ ​12.4 conference_auto_outcall_flags​ ​
• ​ ​12.5 conference_auto_outcall_prefix​ ​
• ​ ​12.6 conference_auto_outcall_timeout​ ​
• ​ ​12.7 conference_auto_outcall_maxwait​ ​
• ​ ​12.8 conference_controls​ ​
• ​ ​12.9 conference_enter_sound​ ​
• ​ ​12.10 conference_last_matching_digits​ ​
• ​ ​12.11 last_transferred_conference​ ​
• ​ ​12.12 conference_member_id​ ​
• ​ ​12.13 conference_uuid​ ​
• ​ ​12.14 hangup_after_conference​ ​

• ​ ​13 Code Execution Related​ ​

• ​ ​13.1 api_hangup_hook​ ​
• ​ ​13.2 bridge_pre_execute_aleg_app​ ​
• ​ ​13.3 bridge_pre_execute_aleg_data​ ​
• ​ ​13.4 bridge_pre_execute_bleg_app​ ​
• ​ ​13.5 bridge_pre_execute_bleg_data​ ​
• ​ ​13.6 exec_after_bridge_app​ ​
• ​ ​13.7 exec_after_bridge_arg​ ​
• ​ ​13.8 The execute_on family​ ​

• ​ ​13.8.1 execute_on_answer​ ​
• ​ ​13.8.2 execute_on_media​ ​
• ​ ​13.8.3 execute_on_preanswer​ ​
• ​ ​13.8.4 execute_on_ring​ ​
• ​ ​13.8.5 execute_on_sip_reinvite​ ​

• ​ ​13.9 failed_xml_cdr_prefix​ ​
• ​ ​13.10 fail_on_single_reject​ ​
• ​ ​13.11 intercept_unbridged_only​ ​
• ​ ​13.12 intercept_unanswered_only​ ​
• ​ ​13.13 session_in_hangup_hook​ ​

• ​ ​14 Caller ID Related​ ​

• ​ ​14.1 caller_id_name​ ​
• ​ ​14.2 caller_id_number​ ​
• ​ ​14.3 effective_caller_id_name​ ​
• ​ ​14.4 effective_caller_id_number​ ​
• ​ ​14.5 sip_cid_type​ ​
• ​ ​14.6 effective_sip_cid_in_1xx​ ​

• ​ ​15 Callee ID Related​ ​

• ​ ​15.1 sip_callee_id_name​ ​
• ​ ​15.2 sip_callee_id_number​ ​

• ​ ​16 Call Recording Related​ ​

• ​ ​16.1 Audio File Metadata​ ​

• ​ ​16.1.1 RECORD_TITLE​ ​
• ​ ​16.1.2 RECORD_COPYRIGHT​ ​
• ​ ​16.1.3 RECORD_SOFTWARE​ ​
• ​ ​16.1.4 RECORD_ARTIST​ ​
• ​ ​16.1.5 RECORD_COMMENT​ ​
• ​ ​16.1.6 RECORD_DATE​ ​
• ​ ​16.1.7 RECORD_STEREO​ ​

• ​ ​16.2 record_fill_cng​ ​
• ​ ​16.3 RECORD_HANGUP_ON_ERROR​ ​
• ​ ​16.4 RECORD_DISCARDED​ ​
• ​ ​16.5 record_post_process_exec_api​ ​
• ​ ​16.6 record_post_process_exec_app​ ​
• ​ ​16.7 record_restart_limit_on_dtmf​ ​
• ​ ​16.8 record_sample_rate​ ​
• ​ ​16.9 record_waste_resources​ ​

• ​ ​17 Codec Related​ ​

• ​ ​17.1 absolute_codec_string​ ​
• ​ ​17.2 codec_string​ ​
• ​ ​17.3 inherit_codec​ ​
• ​ ​17.4 read_codec​ ​
• ​ ​17.5 write_codec​ ​
• ​ ​17.6 passthru_ptime_mismatch​ ​
• ​ ​17.7 sip_renegotiate_codec_on_reinvite​ ​
• ​ ​17.8 conference_enforce_security​ ​
• ​ ​17.9 suppress-cng​ ​

• ​ ​18 IVR related​ ​

• ​ ​18.1 ivr_menu_terminator​ ​
• ​ ​18.2 detect_speech_result​ ​

• ​ ​19 SIP related variables​ ​

• ​ ​19.1 disable_hold​ ​
• ​ ​19.2 sip_acl_authed_by​ ​
• ​ ​19.3 sip_acl_token​ ​
• ​ ​19.4 sip_copy_multipart​ ​
• ​ ​19.5 sip_invite_params​ ​
• ​ ​19.6 sip_invite_domain​ ​
• ​ ​19.7 sip_invite_from_params​ ​
• ​ ​19.8 sip_invite_to_params​ ​
• ​ ​19.9 sip_invite_contact_params​ ​
• ​ ​19.10 sip_network_destination​ ​
• ​ ​19.11 sip_auth_username​ ​
• ​ ​19.12 sip_auth_password​ ​
• ​ ​19.13 sip_auto_simplify​ ​
• ​ ​19.14 sip_callee_id_name​ ​
• ​ ​19.15 sip_callee_id_number​ ​
• ​ ​19.16 sip_force_audio_fmtp​ ​
• ​ ​19.17 sip_invite_req_uri​ ​
• ​ ​19.18 sip_invite_from_uri​ ​
• ​ ​19.19 sip_invite_to_uri​ ​
• ​ ​19.20 sip_ignore_reinvites​ ​
• ​ ​19.21 sip_has_crypto​ ​
• ​ ​19.22 sip_secure_media​ ​
• ​ ​19.23 timer_name​ ​
• ​ ​19.24 ignore_display_updates​ ​
• ​ ​19.25 deny_refer_requests​ ​

• ​ ​20 SDP Manipulation​ ​

• ​ ​20.1 sdp_m_per_ptime​ ​
• ​ ​20.2 switch_r_sdp​ ​
• ​ ​20.3 switch_l_sdp​ ​
• ​ ​20.4 switch_m_sdp​ ​
• ​ ​20.5 sip_append_audio_sdp​ ​
• ​ ​20.6 sip_ignore_183nosdp​ ​
• ​ ​20.7 verbose_sdp​ ​
• ​ ​20.8 sip_local_sdp_str​ ​
• ​ ​20.9 sip_recovery_break_rfc​ ​
• ​ ​20.10 sip_enable_soa​ ​

• ​ ​21 FIFO related variables​ ​

• ​ ​21.1 fifo_bridged​ ​
• ​ ​21.2 fifo_caller_consumer_import​ ​
• ​ ​21.3 fifo_consumer_caller_import​ ​
• ​ ​21.4 fifo_manual_bridged​ ​
• ​ ​21.5 fifo_position​ ​
• ​ ​21.6 fifo_role​ ​
• ​ ​21.7 transfer_after_bridge​ ​

• ​ ​22 Playback related variables​ ​

• ​ ​22.1 playback_terminators​ ​
• ​ ​22.2 sound_prefix​ ​
• ​ ​22.3 playback_terminator_used​ ​
• ​ ​22.4 playback_ms​ ​
• ​ ​22.5 playback_samples​ ​
• ​ ​22.6 playback_sleep_val​ ​
• ​ ​22.7 playback_delimiter​ ​
• ​ ​22.8 sleep_eat_digits​ ​
• ​ ​22.9 playback_timeout_sec​ ​

• ​ ​23 Originate related variables​ ​

• ​ ​23.1 execute_on_originate​ ​
• ​ ​23.2 leg_delay_start​ ​
• ​ ​23.3 originate_disposition​ ​
• ​ ​23.4 originate_retries​ ​
• ​ ​23.5 originate_retry_sleep_ms​ ​
• ​ ​23.6 originate_timeout​ ​
• ​ ​23.7 originating_leg_uuid​ ​
• ​ ​23.8 origination_channel_name​ ​
• ​ ​23.9 origination_caller_id_name​ ​
• ​ ​23.10 origination_caller_id_number​ ​
• ​ ​23.11 origination_cancel_key​ ​
• ​ ​23.12 origination_privacy​ ​
• ​ ​23.13 origination_uuid​ ​
• ​ ​23.14 originator​ ​
• ​ ​23.15 originator_codec​ ​

• ​ ​24 RTP/media related variables​ ​

• ​ ​24.1 bypass_media​ ​
• ​ ​24.2 bypass_media_after_bridge​ ​
• ​ ​24.3 proxy_media​ ​
• ​ ​24.4 rtp_autoflush​ ​
• ​ ​24.5 rtp_autoflush_during_bridge​ ​
• ​ ​24.6 disable_rtp_auto_adjust​ ​
• ​ ​24.7 progress_timeout​ ​
• ​ ​24.8 bridge_answer_timeout​ ​
• ​ ​24.9 ignore_early_media​ ​
• ​ ​24.10 ringback​ ​
• ​ ​24.11 instant_ringback​ ​
• ​ ​24.12 transfer_ringback​ ​
• ​ ​24.13 disable_hold​ ​

• ​ ​25 RTCP Related​ ​

• ​ ​25.1 rtcp_packet_count​ ​
• ​ ​25.2 rtcp_octet_count​ ​

• ​ ​26 Camp-on related variables​ ​

• ​ ​26.1 campon​ ​
• ​ ​26.2 campon_retries​ ​
• ​ ​26.3 campon_timeout​ ​
• ​ ​26.4 campon_sleep​ ​
• ​ ​26.5 campon_fallback_exten​ ​
• ​ ​26.6 campon_fallback_dialplan​ ​
• ​ ​26.7 campon_fallback_context​ ​
• ​ ​26.8 campon_hold_music​ ​
• ​ ​26.9 campon_stop_key​ ​
• ​ ​26.10 campon_announce_sound​ ​

• ​ ​27 Answer confirmation variables​ ​

• ​ ​27.1 group_confirm_file​ ​
• ​ ​27.2 group_confirm_key​ ​
• ​ ​27.3 group_confirm_cancel_timeout​ ​

• ​ ​28 Voicemail Related Variables​ ​

• ​ ​28.1 voicemail_alternate_greet_id​ ​
• ​ ​28.2 voicemail_greeting_number​ ​
• ​ ​28.3 vm_message_ext​ ​
• ​ ​28.4 vm_cc​ ​
• ​ ​28.5 skip_greeting​ ​
• ​ ​28.6 skip_instructions​ ​
• ​ ​28.7 voicemail_authorized​ ​

• ​ ​29 Events​ ​

• ​ ​29.1 fire_asr_events​ ​

• ​ ​30 System Related Variables​ ​

• ​ ​30.1 base_dir​ ​

• ​ ​31 OpenZap Related Variables​ ​

• ​ ​31.1 openzap_span_number​ ​
• ​ ​31.2 openzap_chan_number​ ​