dialog Module

Bogdan-Andrei Iancu

Voice Sistem SRL

Carsten Bock

ng-voice.com

Edited by

Bogdan-Andrei Iancu

Carsten Bock

Alex Balashov

Olle E. Johansson


Table of Contents

1. Admin Guide
1. Overview
2. How it works
3. Dialog states
4. Dialog profiling
5. Dependencies
5.1. Kamailio Modules
5.2. External Libraries or Applications
6. Parameters
6.1. enable_stats (integer)
6.2. hash_size (integer)
6.3. rr_param (string)
6.4. dlg_flag (integer)
6.5. timeout_avp (string)
6.6. default_timeout (integer)
6.7. early_timeout (integer)
6.8. noack_timeout (integer)
6.9. end_timeout (integer)
6.10. dlg_extra_hdrs (string)
6.11. dlg_match_mode (integer)
6.12. detect_spirals (integer)
6.13. db_url (string)
6.14. db_mode (integer)
6.15. db_update_period (integer)
6.16. db_fetch_rows (integer)
6.17. db_skip_load (integer)
6.18. table_name (string)
6.19. call_id_column (string)
6.20. from_uri_column (string)
6.21. from_tag_column (string)
6.22. to_uri_column (string)
6.23. to_tag_column (string)
6.24. from_cseq_column (string)
6.25. to_cseq_column (string)
6.26. from_route_column (string)
6.27. to_route_column (string)
6.28. from_contact_column (string)
6.29. to_contact_column (string)
6.30. from_sock_column (string)
6.31. to_sock_column (string)
6.32. h_id_column (string)
6.33. h_entry_column (string)
6.34. state_column (string)
6.35. start_time_column (string)
6.36. timeout_column (string)
6.37. sflags_column (string)
6.38. toroute_name_column (string)
6.39. vars_table_name (string)
6.40. vars_h_id_column (string)
6.41. vars_h_entry_column (string)
6.42. vars_key_column (string)
6.43. vars_value_column (string)
6.44. profiles_with_value (string)
6.45. profiles_no_value (string)
6.46. bridge_controller (string)
6.47. bridge_contact (string)
6.48. initial_cbs_inscript (int)
6.49. send_bye (int)
6.50. wait_ack (int)
6.51. ka_timer (int)
6.52. ka_interval (int)
6.53. ka_failed_limit (int)
6.54. timeout_noreset (int)
6.55. timer_procs (int)
6.56. enable_dmq (int)
6.57. track_cseq_updates (int)
6.58. lreq_callee_headers (string)
6.59. event_callback (str)
6.60. h_id_start (int)
6.61. h_id_step (int)
7. Functions
7.1. set_dlg_profile(profile,[value])
7.2. unset_dlg_profile(profile,[value])
7.3. is_in_profile(profile,[value])
7.4. get_profile_size(profile,[value],size)
7.5. dlg_isflagset(flag)
7.6. dlg_setflag(flag)
7.7. dlg_resetflag(flag)
7.8. dlg_bye(side)
7.9. dlg_refer(side, address)
7.10. dlg_manage()
7.11. dlg_bridge(from, to, op)
7.12. dlg_get(callid, ftag, ttag)
7.13. is_known_dlg()
7.14. dlg_set_timeout(timeout [, h_entry, h_id])
7.15. dlg_set_timeout_by_profile(profile, [value], timeout)
7.16. dlg_set_property(attr)
7.17. dlg_remote_profile(cmd, profile, value, uid, expires)
7.18. dlg_set_ruri()
7.19. dlg_db_load_callid(cival)
7.20. dlg_db_load_extra()
8. Statistics
8.1. active_dialogs
8.2. early_dialogs
8.3. processed_dialogs
8.4. expired_dialogs
8.5. failed_dialogs
9. RPC Commands
9.1. dlg.list
9.2. dlg.list_ctx
9.3. dlg.dlg_list
9.4. dlg.dlg_list_ctx
9.5. dlg.terminate_dlg
9.6. dlg.end_dlg
9.7. dlg.profile_get_size
9.8. dlg.profile_list
9.9. dlg.bridge_dlg
9.10. dlg.stats_active
10. Exported Variables
10.1. $DLG_count
10.2. $DLG_status
10.3. $DLG_lifetime
10.4. $dlg(...)
10.5. $dlg_ctx(...)
10.6. $dlg_var(key)
11. Event Routes
11.1. event_route[dialog:start]
11.2. event_route[dialog:end]
11.3. event_route[dialog:failed]
2. Developer Guide
1. Available Functions
1.1. register_dlgcb (dialog, type, cb, param, free_param_cb)
1.2. terminate_dlg (dlg, hdrs)
3. Frequently Asked Questions

List of Examples

1.1. Set enable_stats parameter
1.2. Set hash_size parameter
1.3. Set rr_param parameter
1.4. Set dlg_flag parameter
1.5. Set timeout_avp parameter
1.6. Set default_timeout parameter
1.7. Set early_timeout parameter
1.8. Set noack_timeout parameter
1.9. Set end_timeout parameter
1.10. Set dlf_extra_hdrs parameter
1.11. Set dlg_match_mode parameter
1.12. Set detect_spirals parameter
1.13. Set db_url parameter
1.14. Set db_mode parameter
1.15. Set db_update_period parameter
1.16. Set db_fetch_rows parameter
1.17. Set db_skip_load parameter
1.18. Set table_name parameter
1.19. Set call_id_column parameter
1.20. Set from_uri_column parameter
1.21. Set from_tag_column parameter
1.22. Set to_uri_column parameter
1.23. Set to_tag_column parameter
1.24. Set from_cseq_column parameter
1.25. Set to_cseq_column parameter
1.26. Set from_route_column parameter
1.27. Set to_route_column parameter
1.28. Set from_contact_column parameter
1.29. Set to_contact_column parameter
1.30. Set from_sock_column parameter
1.31. Set to_sock_column parameter
1.32. Set h_id_column parameter
1.33. Set h_entry_column parameter
1.34. Set state_column parameter
1.35. Set start_time_column parameter
1.36. Set timeout_column parameter
1.37. Set sflags_column parameter
1.38. Set toroute_name_column parameter
1.39. Set vars_table_name parameter
1.40. Set vars_h_id_column parameter
1.41. Set vars_h_entry_column parameter
1.42. Set vars_key_column parameter
1.43. Set vars_value_column parameter
1.44. Set profiles_with_value parameter
1.45. Set profiles_no_value parameter
1.46. Set bridge_controller parameter
1.47. Set bridge_contact parameter
1.48. Set initial_cbs_inscript parameter
1.49. Set send_bye parameter
1.50. Set wait_ack parameter
1.51. Set ka_timer parameter
1.52. Set ka_interval parameter
1.53. Set ka_failed_limit parameter
1.54. Set timeout_noreset parameter
1.55. Set timer_procs parameter
1.56. Set enable_dmq parameter
1.57. Set track_cseq_updates parameter
1.58. Set lreq_callee_headers parameter
1.59. Set event_callback parameter
1.60. Set h_id_start parameter
1.61. Set h_id_step parameter
1.62. set_dlg_profile usage
1.63. unset_dlg_profile usage
1.64. is_in_profile usage
1.65. get_profile_size usage
1.66. dlg_isflagset usage
1.67. dlg_setflag usage
1.68. dlg_resetflag usage
1.69. dlg_bye usage
1.70. dlg_refer usage
1.71. dlg_manage usage
1.72. dlg_bridge usage
1.73. dlg_get usage
1.74. is_known_dlg() usage
1.75. dlg_set_timeout usage
1.76. dlg_set_timeout_by_profile usage
1.77. dlg_set_property usage
1.78. dlg_remote_profile usage
1.79. dlg_set_ruri() usage
1.80. dlg_db_load_callid() usage
1.81. dlg_db_load_extra() usage

Chapter 1. Admin Guide

Table of Contents

1. Overview
2. How it works
3. Dialog states
4. Dialog profiling
5. Dependencies
5.1. Kamailio Modules
5.2. External Libraries or Applications
6. Parameters
6.1. enable_stats (integer)
6.2. hash_size (integer)
6.3. rr_param (string)
6.4. dlg_flag (integer)
6.5. timeout_avp (string)
6.6. default_timeout (integer)
6.7. early_timeout (integer)
6.8. noack_timeout (integer)
6.9. end_timeout (integer)
6.10. dlg_extra_hdrs (string)
6.11. dlg_match_mode (integer)
6.12. detect_spirals (integer)
6.13. db_url (string)
6.14. db_mode (integer)
6.15. db_update_period (integer)
6.16. db_fetch_rows (integer)
6.17. db_skip_load (integer)
6.18. table_name (string)
6.19. call_id_column (string)
6.20. from_uri_column (string)
6.21. from_tag_column (string)
6.22. to_uri_column (string)
6.23. to_tag_column (string)
6.24. from_cseq_column (string)
6.25. to_cseq_column (string)
6.26. from_route_column (string)
6.27. to_route_column (string)
6.28. from_contact_column (string)
6.29. to_contact_column (string)
6.30. from_sock_column (string)
6.31. to_sock_column (string)
6.32. h_id_column (string)
6.33. h_entry_column (string)
6.34. state_column (string)
6.35. start_time_column (string)
6.36. timeout_column (string)
6.37. sflags_column (string)
6.38. toroute_name_column (string)
6.39. vars_table_name (string)
6.40. vars_h_id_column (string)
6.41. vars_h_entry_column (string)
6.42. vars_key_column (string)
6.43. vars_value_column (string)
6.44. profiles_with_value (string)
6.45. profiles_no_value (string)
6.46. bridge_controller (string)
6.47. bridge_contact (string)
6.48. initial_cbs_inscript (int)
6.49. send_bye (int)
6.50. wait_ack (int)
6.51. ka_timer (int)
6.52. ka_interval (int)
6.53. ka_failed_limit (int)
6.54. timeout_noreset (int)
6.55. timer_procs (int)
6.56. enable_dmq (int)
6.57. track_cseq_updates (int)
6.58. lreq_callee_headers (string)
6.59. event_callback (str)
6.60. h_id_start (int)
6.61. h_id_step (int)
7. Functions
7.1. set_dlg_profile(profile,[value])
7.2. unset_dlg_profile(profile,[value])
7.3. is_in_profile(profile,[value])
7.4. get_profile_size(profile,[value],size)
7.5. dlg_isflagset(flag)
7.6. dlg_setflag(flag)
7.7. dlg_resetflag(flag)
7.8. dlg_bye(side)
7.9. dlg_refer(side, address)
7.10. dlg_manage()
7.11. dlg_bridge(from, to, op)
7.12. dlg_get(callid, ftag, ttag)
7.13. is_known_dlg()
7.14. dlg_set_timeout(timeout [, h_entry, h_id])
7.15. dlg_set_timeout_by_profile(profile, [value], timeout)
7.16. dlg_set_property(attr)
7.17. dlg_remote_profile(cmd, profile, value, uid, expires)
7.18. dlg_set_ruri()
7.19. dlg_db_load_callid(cival)
7.20. dlg_db_load_extra()
8. Statistics
8.1. active_dialogs
8.2. early_dialogs
8.3. processed_dialogs
8.4. expired_dialogs
8.5. failed_dialogs
9. RPC Commands
9.1. dlg.list
9.2. dlg.list_ctx
9.3. dlg.dlg_list
9.4. dlg.dlg_list_ctx
9.5. dlg.terminate_dlg
9.6. dlg.end_dlg
9.7. dlg.profile_get_size
9.8. dlg.profile_list
9.9. dlg.bridge_dlg
9.10. dlg.stats_active
10. Exported Variables
10.1. $DLG_count
10.2. $DLG_status
10.3. $DLG_lifetime
10.4. $dlg(...)
10.5. $dlg_ctx(...)
10.6. $dlg_var(key)
11. Event Routes
11.1. event_route[dialog:start]
11.2. event_route[dialog:end]
11.3. event_route[dialog:failed]

1. Overview

Kamailio can behave as a stateful proxy through the TM module. However, "stateful" in this context refers to transaction state, not dialog state. Certain applications may benefit from an awareness of "calls" in the proxy, not just SIP transactions.

For example, a common need is to limit the number of calls that can be made concurrently by an endpoint, account, user group, etc. In order to count the number of calls in progress, it is necessary for the proxy to be aware of whole dialogs, not just transactions, and to provide some means of programmatically classifying these dialogs. This is just one common application discussed for illustrative purposes; there are many others.

The dialog module provides dialog awareness for the Kamailio proxy. It's functionality is to keep track of the current dialogs, to offer information about them (e.g. how many dialogs are active), and to manage various characteristics of dialogs. The module exports several functions that can be used directly from the configuration route script as well as functions for the RPC interface.

This module also provides a API foundation on which to build more complex dialog-oriented functionality in other Kamailio modules.

2. How it works

To create the dialog associated with an initial INVITE request, execute the function dlg_manage() or set the flag specified by parameter dlg_flag (Section 6.4, “dlg_flag (integer)”) before creating the corresponding transaction.

The dialog is automatically destroyed when a BYE is received. In case of no BYE, the dialog lifetime is controlled via the default timeout (see default_timeout - Section 6.6, “default_timeout (integer)”) and custom timeout (see timeout_avp - Section 6.5, “timeout_avp (string)”). The dialog timeout is reset each time a sequential request is processed.

3. Dialog states

Dialogs have states that are shown in the RPC interface as well as stored in the database.

  • 1 : Unconfirmed dialog

  • 2 : Early dialog (ringing)

  • 3 : Confirmed dialog (waiting for ACK)

  • 4 : Confirmed dialog (active call)

  • 5 : Deleted dialog

The early and deleted dialog states are not updated in database storage.

4. Dialog profiling

Dialog profiling is a mechanism that helps in classifying, sorting and keeping track of certain types of dialogs. The classification criteria can be any attributes desired by the administrator; it can be SIP message attributes, other pseudo-variables, custom values, etc. Dialogs can be dynamically added into one or more profile tables. Logically, each profile table can have a special meaning (like dialogs outside the domain, dialogs terminated to the PSTN, etc.).

There are two types of profiles:

  • with no value - a dialog simply belongs to a profile (for instance, an outbound calls profile). There is no other additional information to describe the dialog beyond its membership in the profile per se.

  • with value - a dialog belongs to a profile having a certain value (like in a caller profile, where the value is the caller ID). The membership of the dialog in the profile is strictly related to the value. For example, if the account ID of the caller is stored in the pseudo-variable $var(account_id), you can use $var(account_id) as a value/key by which to group dialogs so that you can count the number of open dialogs for each account, enforce concurrent call limits as necessary, etc.

A dialog can be added to multiple profiles at the same time.

Profiles are visible (at the moment) in the request route (for initial and sequential requests) and in the branch, failure and reply routes of the original request.

5. Dependencies

5.1. Kamailio Modules

The following modules must be loaded before this module:

  • TM - Transaction module

  • RR - Record-Route module

  • PV - Pseudovariables module

5.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • None.

6. Parameters

6.1. enable_stats (integer)

If statistics support should be enabled or not. Via statistics variables, the module provide information about the dialog processing. Set it to zero to disable or to non-zero to enable it.

Default value is 1 (enabled).

Example 1.1. Set enable_stats parameter

...
modparam("dialog", "enable_stats", 0)
...

6.2. hash_size (integer)

The size of the hash table internally used to keep the dialogs. A larger table is much faster but consumes more memory. The hash size must be a power of two.

IMPORTANT: If dialog information should be stored in a database, a constant hash_size should be used, otherwise the restoring process will not take place. If you really want to modify the hash_size, you must delete all table's rows before restarting the server.

Default value is 4096.

Example 1.2. Set hash_size parameter

...
modparam("dialog", "hash_size", 1024)
...

6.3. rr_param (string)

Name of the Record-Route parameter used to store the dialog cookie. It is used for the fast matching of sequential requests to tracked dialogs.

Default value is did.

Example 1.3. Set rr_param parameter

...
modparam("dialog", "rr_param", "xyz")
...

6.4. dlg_flag (integer)

Flag to be used for marking if a dialog should be constructed for the current request (this make sense only for initial requests).

Note: it is not needed to set this parameter and its corresponding flag for initial request in case the dlg_manage() function is used. In other words, using dlg_manage() alone is enough.

Default value is none.

Example 1.4. Set dlg_flag parameter

...
modparam("dialog", "dlg_flag", 4)
...

6.5. timeout_avp (string)

The specification of an AVP that contains a custom timeout value (in seconds) for the dialog. It may be used only in a request (initial or sequential) context.

Default value is none.

Example 1.5. Set timeout_avp parameter

...
modparam("dialog", "timeout_avp", "$avp(i:10)")
...

6.6. default_timeout (integer)

The default dialog timeout (in seconds), in the absence of a custom value provided in an AVP.

Default value is 43200 (12 hours).

Example 1.6. Set default_timeout parameter

...
modparam("dialog", "default_timeout", 21600)
...

6.7. early_timeout (integer)

The timeout (in seconds) after which the dialogs in unconfirmed or early state (no final response received) are destroyed.

Default value is 300 (5 minutes).

Example 1.7. Set early_timeout parameter

...
modparam("dialog", "early_timeout", 180)
...

6.8. noack_timeout (integer)

The timeout (in seconds) after which the dialogs which were answered with 200ok but didn't receive the ACK are marked for termination (the lifetime is set to 10 more seconds).

Default value is 60 (1 minute).

Example 1.8. Set noack_timeout parameter

...
modparam("dialog", "noack_timeout", 90)
...

6.9. end_timeout (integer)

The timeout (in seconds) after which the dialogs in terminated state are destroyed.

Default value is 300 (5 minutes).

Example 1.9. Set end_timeout parameter

...
modparam("dialog", "end_timeout", 180)
...

6.10. dlg_extra_hdrs (string)

A string containing the extra headers (full format, with EOH) to be added to requests generated locally by the module (like BYEs).

Default value is NULL.

Example 1.10. Set dlf_extra_hdrs parameter

...
modparam("dialog", "dlg_extra_hdrs", "Hint: credit expired\r\n")
...

6.11. dlg_match_mode (integer)

How the sequential requests should be matched against the known dialogs. The modes are a combination of matching based on a cookie (DID) stored as cookie in Record-Route header and matching based on SIP elements (as in RFC 3261).

Note: DID-based matching does not replace callid/fromtag/totag comparison. It will speed up dialog matching by not iterating over the whole dialog list for callid/fromtag/totag comparison, but instead it uses a hash table to find the respective dialog and then doing only one callid/fromtag/totag comparison. Thus, there is no security issue when using DID based matching. Use DID_FALLBACK for maximum interoperability or use DID_ONLY to reject buggy clients or hacking attempts. DID_NONE is only useful, when you want to hide dialog-tracking from the users (preventing the DID Record-Route cookie).

The supported modes are:

  • 0 - DID_ONLY - the match is done exclusively based on DID;

  • 1 - DID_FALLBACK - the match is first tried based on DID and if not present, it will fall back to SIP matching;

  • 2 - DID_NONE - the match is done exclusively based on SIP elements; no DID information is added in RR.

Default value is 0 (DID_ONLY).

Example 1.11. Set dlg_match_mode parameter

...
modparam("dialog", "dlg_match_mode", 1)
...

6.12. detect_spirals (integer)

Whether spirals (i.e., messages routed through the proxy multiple times) should be detected.

If set to 0, spirals will not be detected and result in the generation of a new, possibly dangling dialog structure per occurring spiral. If set to 1, spirals are detected and internally mapped to existing dialog structures.

Default value is 1.

Example 1.12. Set detect_spirals parameter

...
modparam("dialog", "detect_spirals", 1)
...

6.13. db_url (string)

In order to store information about dialogs in a database, a database URL must be specified.

Default value is mysql://kamailio:kamailiorw@localhost/kamailio.

Example 1.13. Set db_url parameter

...
modparam("dialog", "db_url", "dbdriver://username:password@dbhost/dbname")
...

6.14. db_mode (integer)

Mode of synchronisation of dialog information from memory to an underlying database (if desired):

The supported modes are:

  • 0 - NO_DB - the memory content is not flushed into DB;

  • 1 - REALTIME - any dialog information changes will be reflected into the database immediately.

  • 2 - DELAYED - the dialog information changes will be flushed into DB periodically, based on a timer routine.

  • 3 - SHUTDOWN - the dialog information will be flushed into DB only at shutdown - no runtime updates.

Default value is 0.

Example 1.14. Set db_mode parameter

...
modparam("dialog", "db_mode", 1)
...

6.15. db_update_period (integer)

The interval (seconds) at which to update dialogs' information, if the server is configured to store the dialog information at a given interval. Too short an interval will generate intensive database operations, while an excessively long one will miss dialogs with a short lifetime.

Default value is 60 seconds.

Example 1.15. Set db_update_period parameter

...
modparam("dialog", "db_update_period", 120)
...

6.16. db_fetch_rows (integer)

The number of the rows to be fetched at once from database when loading the dialog records at startup from the database. This value can be used to tune the load time at startup. For 1MB of private memory (default), it should be below 400. The database driver must support the fetch_result() capability. A value of 0 means the database fetch is not limited.

Default value is 200.

Example 1.16. Set db_fetch_rows parameter

...
modparam("dialog", "db_fetch_rows", 500)
...

6.17. db_skip_load (integer)

Set db_skip_load to 1, to skip the loading of dialog data from the database.

Default value is 0 ( not skipped ).

Example 1.17. Set db_skip_load parameter

...
modparam("dialog", "db_skip_load", 1)
...

6.18. table_name (string)

Database table name used for storing dialog information.

Default value is dialog.

Example 1.18. Set table_name parameter

...
modparam("dialog", "table_name", "my_dialog")
...

6.19. call_id_column (string)

The column name in the database to store the dialog call-id.

Default value is callid.

Example 1.19. Set call_id_column parameter

...
modparam("dialog", "call_id_column", "callid_c_name")
...

6.20. from_uri_column (string)

The column name in the database to store the caller's SIP address (URI).

Default value is from_uri.

Example 1.20. Set from_uri_column parameter

...
modparam("dialog", "from_uri_column", "from_uri_c_name")
...

6.21. from_tag_column (string)

The column name in the database to store the From header tag from the INVITE request.

Default value is from_tag.

Example 1.21. Set from_tag_column parameter

...
modparam("dialog", "from_tag_column", "from_tag_c_name")
...

6.22. to_uri_column (string)

The column name in the database to store the callee's SIP address (URI).

Default value is to_uri.

Example 1.22. Set to_uri_column parameter

...
modparam("dialog", "to_uri_column", "to_uri_c_name")
...

6.23. to_tag_column (string)

The column name in the database to store the To header tag from the 200 OK response to the INVITE request, if present.

Default value is to_tag.

Example 1.23. Set to_tag_column parameter

...
modparam("dialog", "to_tag_column", "to_tag_c_name")
...

6.24. from_cseq_column (string)

The column name in the database to store the Cseq from caller side.

Default value is caller_cseq.

Example 1.24. Set from_cseq_column parameter

...
modparam("dialog", "from_cseq_column", "from_cseq")
...

6.25. to_cseq_column (string)

The column name in the database to store the cseq from callee side.

Default value is callee_cseq.

Example 1.25. Set to_cseq_column parameter

...
modparam("dialog", "to_cseq_column", "to_cseq")
...

6.26. from_route_column (string)

The column name in the database to store the route records from caller side (proxy to caller).

Default value is caller_route_set.

Example 1.26. Set from_route_column parameter

...
modparam("dialog", "from_route_column", "rroute_from")
...

6.27. to_route_column (string)

The column name in the database to store the route records from callee side (proxy to callee).

Default value is callee_route_set.

Example 1.27. Set to_route_column parameter

...
modparam("dialog", "to_route_column", "rroute_to")
...

6.28. from_contact_column (string)

The column name in the database to store the caller's contact uri.

Default value is caller_contact.

Example 1.28. Set from_contact_column parameter

...
modparam("dialog", "from_contact_column", "from_contact_uri")
...

6.29. to_contact_column (string)

The column name in the database to store the callee's contact uri.

Default value is callee_contact.

Example 1.29. Set to_contact_column parameter

...
modparam("dialog", "to_contact_column", "to_contact_uri")
...

6.30. from_sock_column (string)

The column name in the database to store the information about the local interface receiving the traffic from caller.

Default value is caller_sock.

Example 1.30. Set from_sock_column parameter

...
modparam("dialog", "from_sock_column", "socket_from")
...

6.31. to_sock_column (string)

The column name in the database to store information about the local interface receiving the traffic from callee.

Default value is callee_sock.

Example 1.31. Set to_sock_column parameter

...
modparam("dialog", "to_sock_column", "socket_to")
...

6.32. h_id_column (string)

The column name in the database to store the dialogs' hash id information.

Default value is hash_id.

Example 1.32. Set h_id_column parameter

...
modparam("dialog", "h_id_column", "hash_id_c_name")
...

6.33. h_entry_column (string)

The column name in the database to store the dialog's hash entry information.

Default value is hash_entry.

Example 1.33. Set h_entry_column parameter

...
modparam("dialog", "h_entry_column", "h_entry_c_name")
...

6.34. state_column (string)

The column name in the database to store the dialog's state information.

Default value is state.

Example 1.34. Set state_column parameter

...
modparam("dialog", "state_column", "state_c_name")
...

6.35. start_time_column (string)

The column name in the database to store the dialog's start time information.

Default value is start_time.

Example 1.35. Set start_time_column parameter

...
modparam("dialog", "start_time_column", "start_time_c_name")
...

6.36. timeout_column (string)

The column name in the database to store the dialog's timeout.

Default value is timeout.

Example 1.36. Set timeout_column parameter

...
modparam("dialog", "timeout_column", "timeout_c_name")
...

6.37. sflags_column (string)

The column name in the database to store the dialog script flags.

Default value is sflags.

Example 1.37. Set sflags_column parameter

...
modparam("dialog", "sflags_column", "s_flags")
...

6.38. toroute_name_column (string)

The column name in the database to store the index of the route to be executed at timeout.

Default value is toroute_name.

Example 1.38. Set toroute_name_column parameter

...
modparam("dialog", "toroute_name_column", "timeout_route")
...

6.39. vars_table_name (string)

If you want to store the dialog variables ($dlg_var(name)) for a dialog in a database a table name must be specified.

Default value is dialog_vars.

Example 1.39. Set vars_table_name parameter

...
modparam("dialog", "vars_table_name", "my_dialog_vars")
...

6.40. vars_h_id_column (string)

The column name in the database to store the dialog's hash id information (as a reference to the dialog table).

Default value is hash_id.

Example 1.40. Set vars_h_id_column parameter

...
modparam("dialog", "vars_h_id_column", "vars_h_id_name")
...

6.41. vars_h_entry_column (string)

The column name in the database to store the dialog's hash entry information (as a reference to the dialog table).

Default value is hash_entry.

Example 1.41. Set vars_h_entry_column parameter

...
modparam("dialog", "vars_h_entry_column", "vars_h_entry_name")
...

6.42. vars_key_column (string)

The column name in the database to store the names (keys) of a dialog variable.

Default value is dialog_key.

Example 1.42. Set vars_key_column parameter

...
modparam("dialog", "vars_key_column", "vars_key_name")
...

6.43. vars_value_column (string)

The column name in the database to store the values of a dialog variable.

Default value is dialog_value.

Example 1.43. Set vars_value_column parameter

...
modparam("dialog", "vars_value_column", "vars_value_name")
...

6.44. profiles_with_value (string)

List of names for profiles with values, separated with semi-colon ";".

Default value is empty.

Example 1.44. Set profiles_with_value parameter

...
modparam("dialog", "profiles_with_value", "caller ; my_profile")
...

6.45. profiles_no_value (string)

List of names for profiles without values, separated with semi-colon ";".

Default value is empty.

Example 1.45. Set profiles_no_value parameter

...
modparam("dialog", "profiles_no_value", "inbound ; outbound")
...

6.46. bridge_controller (string)

SIP address to be used in From header when initiating a call bridge.

Default value is sip:controller@kamailio.org.

Example 1.46. Set bridge_controller parameter

...
modparam("dialog", "bridge_controller", "sip:ctd@kamailio.org")
...

6.47. bridge_contact (string)

SIP address to be used in Contact header when doing a call bridge.

Default value is sip:controller@kamailio.org:5060.

Example 1.47. Set bridge_contact parameter

...
modparam("dialog", "bridge_contact", "sip:ctd@127.0.0.1:5060")
...

6.48. initial_cbs_inscript (int)

If the initial dialog callbacks (i.e., DLGCB_CREATED and DLGCB_SPIRALED) should be executed in-script or post-script. If dlg_manage() is not used, the setting of this parameter does not matter; otherwise, initial callbacks will be executed directly after dlg_manage() is called if this parameter is enabled. If it is disabled, initial callback execution will be postponed until configuration script execution completes.

The supported values are:

  • 0 - POST-SCRIPT - execute initial callbacks after the script completes;

  • 1 - IN-SCRIPT - execute initial callbacks during script execution, i.e., right after dlg_manage() is called;

Default value is 1.

Example 1.48. Set initial_cbs_inscript parameter

...
modparam("dialog", "initial_cbs_inscript", 0)
...

6.49. send_bye (int)

If set to 1, BYE requests will be sent out for each dialog that timed out. It is an alternative to $dlg_ctx(timeout_bye)=1 for all dialogs.

Default value is 0.

Example 1.49. Set send_bye parameter

...
modparam("dialog", "send_bye", 1)
...

6.50. wait_ack (int)

If set to 1, dialog will be kept a bit longer in memory in order to absorb the ACK negative replies of initial INVITE. If not, the dialog is destroyed when negative reply is sent out (less internal complexity).

Default value is 1.

Example 1.50. Set wait_ack parameter

...
modparam("dialog", "wait_ack", 0)
...

6.51. ka_timer (int)

Keep-alive timer step - how often to execute the callback to send dialog keep alives (SIP OPTIONS requests within dialog). The value represents the number of seconds.

Default value is 0 (no keep alive).

Example 1.51. Set ka_timer parameter

...
modparam("dialog", "ka_timer", 10)
...

6.52. ka_interval (int)

The interval between keep alives within dialog (SIP OPTIONS requests), sent to caller or callee. The keep alive request will be sent by the first callback fired by KA timer after the ka_interval elapsed from dialog setup or previous keep-alive. The value represents the number of seconds.

If the requests times out (generating a 408) or if the UA responds with 481 the lifetime is set to 10 seconds. When lifetime expires the dialog will be terminated. Any other response (including error responses) will reset the timers.

Default value is 0 (no keep alive). The lowest settable interval is 30 seconds.

Example 1.52. Set ka_interval parameter

...
modparam("dialog", "ka_interval", 300)
...

6.53. ka_failed_limit (int)

The number of failed keep-alive requests that is accepted before generating a dialog timeout.

Default value is 1.

Example 1.53. Set ka_failed_limit parameter

...
modparam("dialog", "ka_failed_limit", 5)
...

6.54. timeout_noreset (int)

If set to 1, the dialog timeout won't be reset each time a sequential request is processed. It is an alternative to dlg_set_property("timeout-noreset") for all dialogs.

Default value is 0.

Example 1.54. Set timeout_noreset parameter

...
modparam("dialog", "timeout_noreset", 1)
...

6.55. timer_procs (int)

If set to 1, the dialog module will start a separate dialog timer process to execute dialog timeout tasks. The default is to use the core timer process.

Default value is 0 (use core timer process).

Example 1.55. Set timer_procs parameter

...
modparam("dialog", "timer_procs", 1)
...

6.56. enable_dmq (int)

If set to 1, the dialog will be synced via dmq. For now, only very basic dialog info is shared, just enough to have synced profiles. Notably, it is not possible to send in-dialog requests on any but the original proxy instance.

Default value is 0.

Example 1.56. Set enable_dmq parameter

...
modparam("dialog", "enable_dmq", 1)
...

6.57. track_cseq_updates (int)

Enable the callbacks for tracking if CSeq number needs to be updated. It is the case when the INVITE has to be authenticated to downstream provider using uac_auth() from uac module.

This is done only for requests in downstream direction. The CSeq difference is stored in $dlg_var(cseq_diff), be sure this variable is not overwritten via config operation.

Default value is 0 (disabled).

Example 1.57. Set track_cseq_updates parameter

...
modparam("dialog", "track_cseq_updates", 1)
...

6.58. lreq_callee_headers (string)

SIP headers to be added when sending local generated requests (e.g., BYE) to callee. It can be useful when you use topoh module with call-id masking (see the docs of topoh module).

Default value is null.

Example 1.58. Set lreq_callee_headers parameter

...
modparam("dialog", "lreq_callee_headers", "TH: dlh\r\n")
...

6.59. event_callback (str)

The name of the function in the kemi configuration file (embedded scripting language such as Lua, Python, ...) to be executed instead of event_route[...] blocks.

The function receives a string parameter with the name of the event, the values are: 'dialog:start', 'dialog:end', 'dialog:failed'. It is also executed if '$dlg_ctx(timeout_route)' is set, the callback function being executed with the variable value as parameter.

Default value is 'empty' (no function is executed for events).

Example 1.59. Set event_callback parameter

...
modparam("dialog", "event_callback", "ksr_dialog_event")
...
-- event callback function implemented in Lua
function ksr_dialog_event(evname)
	KSR.info("===== dialog module triggered event: " .. evname .. "\n");
	return 1;
end
...

6.60. h_id_start (int)

Set the offset to be used for generating dialog internal hash id. If set to -1, the h_id_start is set to the value of the server_id global parameter.

Default value is 0.

Example 1.60. Set h_id_start parameter

...
modparam("dialog", "h_id_start", 5)
...

6.61. h_id_step (int)

Set the step to increment the dialog internal hash id.

If the value is greater than 1, the internal hash id is generated with the rule: h_id_start + N * h_id_step. The first value of N is randomly selected at startup, then incremented by 1 for each new dialog. Setting h_id_start and h_id_step to non-default values should be done when using dlg_db_load_callid(...) or dlg_db_load_extra() to load dialog records generated by another Kamailio instance. Pay attention to ensure that those Kamailio instances are not going to generate overlapping dialog hash id values by using different h_id_start and the same h_id_step (h_id_step has to be greater than the maximum value of h_id_start).

Default value is 1.

Example 1.61. Set h_id_step parameter

...
modparam("dialog", "h_id_step", 10)
...

7. Functions

7.1.  set_dlg_profile(profile,[value])

Inserts the current dialog into a profile. Note that if the profile does not support values, they will be silently discarded. Also, there is no check for inserting the same dialog into the same profile multiple times.

Meaning of the parameters is as follows:

  • profile - name of the profile to be added to;

  • value (optional) - string value to define the membership of the dialog in the profile. Note that the profile must support values. Pseudo-variables are supported.

This function can be used from REQUEST_ROUTE, BRANCH_ROUTE, REPLY_ROUTE and FAILURE_ROUTE.

Example 1.62. set_dlg_profile usage

...
set_dlg_profile("inbound_call");
set_dlg_profile("caller","$fu");
...

7.2.  unset_dlg_profile(profile,[value])

Removes the current dialog from a profile.

Meaning of the parameters is as follows:

  • profile - name of the profile to be removed from;

  • value (optional) - string value to define the belonging of the dialog to the profile - note that the profile must support values. Pseudo-variables are supported.

This function can be used from BRANCH_ROUTE, REPLY_ROUTE and FAILURE_ROUTE.

Example 1.63. unset_dlg_profile usage

...
unset_dlg_profile("inbound_call");
unset_dlg_profile("caller","$fu");
...

7.3.  is_in_profile(profile,[value])

Checks if the current dialog belongs to a profile. If the profile is defined with values, then the check is also matching with the specific value provided as parameter.

Note that if the profile is not defined with support for values, the value parameter will be silently discarded.

Meaning of the parameters is as follows:

  • profile - name of the profile to be checked against;

  • value (optional) - string value to be matched during the check. Pseudo-variables are supported.

This function can be used from REQUEST_ROUTE, BRANCH_ROUTE, REPLY_ROUTE and FAILURE_ROUTE.

Example 1.64. is_in_profile usage

...
if (is_in_profile("inbound_call")) {
	log("this request belongs to a inbound call\n");
}
...
if (is_in_profile("caller","XX")) {
	log("this request belongs to a call of user XX\n");
}
...

7.4.  get_profile_size(profile,[value],size)

Returns the number of dialogs belonging to a profile. If the profile supports values, the check can be reinforced to take into account a specific value, i.e. how many dialogs were inserted into the profile with a specific value. If no value is passed, only the membership of the dialog in the profile per se is checked. Note that if the profile does not support values, the value parameter will be silently discarded.

Meaning of the parameters is as follows:

  • profile - name of the profile to get the size for;

  • value (optional) - string value to further restrict the check. Pseudo-variables are supported;

  • size - an AVP or script variable to return the profile size in.

This function can be used from REQUEST_ROUTE, BRANCH_ROUTE, REPLY_ROUTE and FAILURE_ROUTE.

Example 1.65. get_profile_size usage

...
if(get_profile_size("inbound_call","$avp(size)"))
    xlog("currently there are $avp(size) inbound calls\n");
...
if(get_profile_size("caller","$fu","$avp(size)"))
    xlog("currently, the user $fu has $avp(size) active outgoing calls\n");
...

7.5.  dlg_isflagset(flag)

Check if the dialog flag is set or not.

Meaning of the parameters is as follows:

  • flag - index of the flag - can be pseudo-variable.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.66. dlg_isflagset usage

...
if(dlg_isflagset("1"))
{
    ...
}
...

7.6.  dlg_setflag(flag)

Set a dialog flag.

Meaning of the parameters is as follows:

  • flag - index of the flag - can be pseudo-variable.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.67. dlg_setflag usage

...
dlg_setflag("1");
...

7.7.  dlg_resetflag(flag)

Reset the dialog flag.

Meaning of the parameters is as follows:

  • flag - index of the flag - can be pseudo-variable.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.68. dlg_resetflag usage

...
redlg_setflag("1");
...

7.8.  dlg_bye(side)

Send BYE to both parties of a dialog.

Meaning of the parameters is as follows:

  • side - where to send the BYE. It can be: 'caller', 'callee', or 'all' (send to both sides).

This function can be used from ANY_ROUTE.

Example 1.69. dlg_bye usage

...
dlg_bye("all");
...

7.9.  dlg_refer(side, address)

Refer the 'side' to a new SIP 'address'.

Meaning of the parameters is as follows:

  • side - which side of the dialog to REFER. It can be: 'caller' or 'callee'.

  • address - SIP address to refer to.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.70. dlg_refer usage

...
dlg_refer("caller", "sip:announcement@kamailio.org");
...

7.10.  dlg_manage()

Process current SIP request with dialog module. It is an alternative to setting dialog flag for initial INVITE and Route-parameter-callback execution for within-dialog requests.

This function can be used from REQUEST_ROUTE.

Example 1.71. dlg_manage usage

...
modparam("dialog", "default_timeout", 100)
...
request_route {
...
    if(is_method("INVITE") && !has_totag())
    {
        $dlg_ctx(timeout_route) = "DLGTIMEOUT";
        $dlg_ctx(timeout_bye) = 1;
    }
    dlg_manage();
...
}
...

7.11.  dlg_bridge(from, to, op)

Bridge 'from' SIP address to 'to' SIP address via outbound proxy 'op'.

Meaning of the parameters is as follows:

  • from - SIP address of first side to call.

  • to - SIP address to refer from to.

  • op - outbound proxy SIP address.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.72. dlg_bridge usage

...
dlg_bridge("sip:user@kamailio.org", "sip:annoucement@kamailio.org",
   "sip:kamailio.org:5080");
...

7.12.  dlg_get(callid, ftag, ttag)

Search and set current dialog based on Call-ID, From-Tag and To-Tag parameters.

Meaning of the parameters is as follows:

  • callid - SIP call-id.

  • ftag - SIP From tag.

  • ttag - SIP To tag.

This function can be used from BRANCH_ROUTE, REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.

Example 1.73. dlg_get usage

...
if(dlg_get("abcdef", "123", "456"))
{
	dlg_bye("all");
}
...

7.13.  is_known_dlg()

This function checks if the current SIP message being processed belongs to any transaction within an active dialog that the dialog module is currently tracking. This is a check for tracking of any kind, without regard to profiles.

This function has numerous potential applications, among which is that it can be used to strengthen security for loose-routing sequential (in-dialog) requests or responses to them, as by providing a preventative check against spoofing on the proxy level instead of leaving the issue purely to the receiving UA.

This function can be used from REQUEST_ROUTE, BRANCH_ROUTE, REPLY_ROUTE and FAILURE_ROUTE.

Example 1.74. is_known_dlg() usage

...
if(!uri == myself) {
	if(is_known_dlg()) {
		xlog("Request $rm from $ci is in-dialog\n");
	}
}
...

7.14.  dlg_set_timeout(timeout [, h_entry, h_id])

Set the dialog timeout. Dialog timeout will be updated if it was already set. If h_entry and h_id parameters are not provided, the dialog will be searched based on (callid, fromtag, totag) of currently processed SIP message.

Meaning of the parameters is as follows:

  • timeout - the interval in seconds after which the dialog will time out.

  • h_entry - h_entry value of the iternal dialog identifier.

  • h_id - h_id valye if the internal dialog identifier.

This function can be used from ANY_ROUTE.

Example 1.75. dlg_set_timeout usage

...
if(dlg_set_timeout("180", "123", "456"))
{
    ...
}
...

7.15.  dlg_set_timeout_by_profile(profile, [value], timeout)

Like dlg_set_timeout(), but simultaneously sets the timeout of all dialogs in a given profile. Can be constrained by profile value.

Meaning of the parameters is as follows:

  • profile - The dialog profile across which to apply the timeout.

    value (optional) - The profile value to use when applying the dialog timeout.

    timeout - the interval in seconds after which the dialog will time out.

This function can be used from ANY_ROUTE.

Example 1.76. dlg_set_timeout_by_profile usage

...
# All dialogs belonging to user abc123 (tracked via set_dlg_profile())
# will be timed out in 3 seconds.

dlg_set_timeout_by_profile("users", "abc123", "3");
...

7.16.  dlg_set_property(attr)

Set a dialog property - an attribute that enable/disable various behaviours (e.g., sending keep alive requests).

Meaning of the parameters is as follows:

  • attr - name of property. It can be:

    • 'ka-src' - send keep alive OPTION requests to caller
    • 'ka-dst' - send keep alive OPTION requests to callee
    • 'timeout-noreset' - don't reset timeout on in-dialog messages reception

If keep alive is enabled for a dialog, the module will send SIP OPTIONS requests with CSeq lower or equal than last request within dialog, with the scope of detecting if the destination is still in the call. If the keep alive request results in a local timeout or '481 Call Leg/Transaction Does Not Exist', then the dialog is ended from the server.

If 'timeout-noreset' is set, dialog timeout won't be reset upon reception of in-dialog messages (default behavior).

This function can be used from ANY_ROUTE.

Example 1.77. dlg_set_property usage

...
dlg_set_property("ka-src");
dlg_set_property("ka-dst");
dlg_set_property("timeout-noreset");
...

7.17.  dlg_remote_profile(cmd, profile, value, uid, expires)

Manage remote profile via config file. A remote profile item is considered when the dialog is not managed by this server instance. The notification to add/remove can be received via SIP or a RPC command, the operation can be then triggered from configuration file. This should allow counting active dialogs in a profile that are managed by multiple SIP server instances.

Meaning of the parameters is as follows:

  • cmd - the operations to do: add - add an item in profile; rm - remove an item from profile

  • profile - name of profile

  • value - value for profile (if no value is needed for that profile, use an empty string.

  • expires - absolute time (unix timestamp) when this profile item should be removed automatically (time based), if still in the profile

This function can be used from ANY_ROUTE.

Example 1.78. dlg_remote_profile usage

...
$var(exp) = 3600 + $Ts;
dlg_remote_profile("add", "caller", "test", "$sruid", "$var(exp)");
...

7.18.  dlg_set_ruri()

This function sets the R-URI with the corresponding endpoint address stored in dialog structure (i.e., its Contact field).

This function can be used from ANY_ROUTE.

Example 1.79. dlg_set_ruri() usage

...
if(has_totag() and is_present_hf("Route") and uri==myself ) {
	if(dlg_set_ruri()) {
		xlog("Request URI changed from [$ou] to dlg value: [$ru]\n");
	}
}
...

7.19.  dlg_db_load_callid(cival)

Load dialog record from database matching on Call-Id provided as parameter.

This function can be used from ANY_ROUTE.

Example 1.80. dlg_db_load_callid() usage

...
if(has_totag()) {
    if(!is_known_dlg()) {
        dlg_db_load_callid("$ci");
	    if(!is_known_dlg()) {
            xlog("no dialog found with callid: $ci\n");
        }
    }
}
...

7.20.  dlg_db_load_extra()

Load all dialog records from database that are not in memory of the current Kamailio instance.

This function can be used from ANY_ROUTE.

Example 1.81. dlg_db_load_extra() usage

...
if(has_totag()) {
    if(!is_known_dlg()) {
        dlg_db_load_extra();
	    if(!is_known_dlg()) {
            xlog("no dialog found with callid: $ci\n");
        }
    }
}
...

8. Statistics

8.1. active_dialogs

Returns the number of current active dialogs (may be confirmed or not).

8.2. early_dialogs

Returns the number of early dialogs.

8.3. processed_dialogs

Returns the total number of processed dialogs (terminated, expired or active) from the startup.

8.4. expired_dialogs

Returns the total number of expired dialogs from the startup.

8.5. failed_dialogs

Returns the number of failed dialogs.

9. RPC Commands

9.1. dlg.list

Lists the description of all dialogs (active calls).

Name: dlg.list

RPC Command Format:

...
kamcmd dlg.list
...

9.2. dlg.list_ctx

The same as the dlg_list but including in the dialog description the associated context from modules sitting on top of the dialog module.

Name: dlg.list_ctx

RPC Command Format:

...
kamcmd dlg.list_ctx
...

9.3. dlg.dlg_list

Lists the description of one dialog. The dialog identifiers are to be passed as parameter (callid and optionally fromtag).

Name: dlg.dlg_list

Parameters:

  • callid callid of the dialog to be listed.

  • from_tag from tag (as per initial request) of the dialog to be listed.

RPC Command Format:

...
kamcmd dlg.dlg_list abcdrssfrs122444@192.168.1.1 AAdfeEFF33
...
kamcmd dlg.dlg_list abcdrssfrs122444@192.168.1.1
...

9.4. dlg.dlg_list_ctx

The same as the dlg.list_ctx but including in the dialog description the associated context from modules sitting on top of the dialog module.

Name: dlg.dlg_list_ctx

Parameters: see dlg_list

RPC Command Format:

...
kamcmd dlg.list_ctx abcdrssfrs122444@192.168.1.1 AAdfeEFF33
...
kamcmd dlg.list_ctx abcdrssfrs122444@192.168.1.1
...

9.5. dlg.terminate_dlg

Terminates an ongoing dialog by sending BYE in both directions, matching the dialog on call-id, from tag and to tag.

Name: dlg.terminate_dlg

Parameters:

  • callid - callid of dialog to be terminated

  • from_tag - from tag of the dialog to terminated

  • to_tag - to tag of the dialog to terminated

The command works only for confirmed dialogs.

RPC Command Format:

		kamcmd dlg.terminate_dlg callid12345 fromtag123 totag123

9.6. dlg.end_dlg

Terminates an ongoing dialog by sending BYE in both directions.

Name: dlg.end_dlg

Parameters:

  • h_entry - hash entry of the dialog in the internal dialog table

  • h_id - hash id of the dialog on the hash entry

  • extra_hdrs - (optional) string containg extra headers (full format) to be added to the BYE requests.

The values for the h_entry and h_id can be get via the dlg_list RPC command.

RPC Command Format:

...
kamcmd dlg.end_dlg 342 56
...

9.7. dlg.profile_get_size

Returns the number of dialogs belonging to a profile. If the profile supports values, the check can be reinforced to take into account a specific value - how many dialogs were inserted into the profile with a specific value. If no value is passed, only the simply belonging of the dialog to the profile is checked. Note that if the profile does not support values, the value parameter will be silently discarded.

Name: dlg.profile_get_size

Parameters:

  • profile - name of the profile to get the value for.

  • value (optional)- string value to further restrict the check;

RPC Command Format:

...
kamcmd dlg.dlg.profile_get_size inbound_calls
...

9.8. dlg.profile_list

Lists all the dialogs belonging to a profile. If the profile supports values, the check can be reinforced to take into account a specific value, i.e. list only the dialogs that were inserted into the profile with that specific value. If no value is passed, all dialogs belonging to the profile will be listed. Note that if the profile does not supports values, this will be silently discarded.

Name: dlg.profile_list

Parameters:

  • profile - name of the profile to list the dialog for.

  • value (optional)- string value to further restrict the check;

RPC Command Format:

...
kamcmd dlg.profile_list inbound_calls
...

9.9. dlg.bridge_dlg

Bridge two SIP addresses into a call using INVITE(hold)-REFER-BYE mechanism.

Name: dlg.bridge_dlg

Parameters:

  • from - SIP address to initiate the call

  • to - SIP address to refer 'from' to

  • op (optional) - outbound proxy SIP address. If its value is set to '.' (dot), then it is ignored (like it would not have been provided).

  • body (optional) - SDP body for initial INVITE. If its value is set to '.' (dot), then it is ignored (like it would not have been provided). If body is not set via RPC command parameter, then an internal generated SDP with G711a and G711u is used. If its value is set to '' (empty string) or '_' (underline), then the INVITE is sent without an SDP body.

RPC Command Format:

...
kamcmd dlg.bridge_dlg _from_ _to_ _op_
...

9.10. dlg.stats_active

Get stats about active dialogs by scanning internal list of dialogs (not relying on core stats framework).

Name: dlg.stats_active

Parameters: none.

Returned fields

  • starting - initial INVITE has been processed, no ringing or 1xx has been received.

  • connecting - initial INVITE was forwarded and rining or 1xx has been received.

  • answering - initial INVITE received 200ok, but ACK was not handled yet.

  • ongoing - ongoing active dialog, after the ACK was processed.

  • all - all active dialogs, respectively the sum of the above values.

RPC Command Format:

...
kamcmd dlg.stats_active
...

10. Exported Variables

10.1. $DLG_count

Returns the number of current active dialogs (may be confirmed or not).

10.2. $DLG_status

Returns the status of the dialog corresponding to the processed sequential request. This PV will be available only for sequential requests, after doing loose_route().

Value may be:

  • NULL - Dialog not found.

  • 3 - Confirmed by a final reply but no ACK received yet.

  • 4 - Confirmed by a final reply and ACK received.

  • 5 - Dialog ended.

10.3. $DLG_lifetime

Returns the duration (in seconds) of the dialog corresponding to the processed sequential request. The duration is calculated from the dialog confirmation and the current moment. This PV will be available only for sequential requests, after doing loose_route().

NULL will be returned if there is no dialog for the request.

10.4. $dlg(...)

Access to dialog attributes.

10.5. $dlg_ctx(...)

Access to dialog context attributes.

10.6. $dlg_var(key)

This is a read/write variable that can be used to store custom values assigned with a dialog (e.g. the URI of a billing-server, an assigned emergency-server). This pseudo-variable will be available only for subsequential requests after doing loose_route().

Note: You will receive "NULL", if there is no dialog for this request.

11. Event Routes

11.1. event_route[dialog:start]

Executed when 200 OK reply for INVITE is processed.

11.2. event_route[dialog:end]

Executed when the BYE for the call is processed or the dialog timed out.

11.3. event_route[dialog:failed]

Executed when dialog is not completed (300 or greater reply code to INVITE).

Chapter 2. Developer Guide

1. Available Functions

1.1.  register_dlgcb (dialog, type, cb, param, free_param_cb)

Register a new callback to the dialog.

Meaning of the parameters is as follows:

  • struct dlg_cell* dlg - dialog to register callback to. If maybe NULL only for DLGCB_CREATED callback type, which is not a per dialog type.

  • int type - types of callbacks; more types may be register for the same callback function; only DLGCB_CREATED must be register alone. Possible types:

    • DLGCB_LOADED

    • DLGCB_CREATED - called when a new dialog is created - it's a global type (not associated to any dialog)

    • DLGCB_FAILED - called when the dialog was negatively replied (non-2xx) - it's a per dialog type.

    • DLGCB_CONFIRMED_NA - called when the dialog is confirmed (2xx replied) but the setup-concluding ACK message from the caller is yet pending - it's a per dialog type.

    • DLGCB_CONFIRMED - called when the dialog is confirmed (2xx replied) and the setup-concluding ACK message from the caller has been seen - it's a per dialog type.

    • DLGCB_REQ_WITHIN - called when the dialog matches a sequential request (excluding setup-concluding ACK messages which are handled in DLGCB_CONFIRMED) - it's a per dialog type.

    • DLGCB_TERMINATED - called when the dialog is terminated via BYE - it's a per dialog type.

    • DLGCB_TERMINATED_CONFIRMED - called when response to a BYE request is received - it's a per dialog type.

    • DLGCB_EXPIRED - called when the dialog expires without receiving a BYE - it's a per dialog type.

    • DLGCB_EARLY - called when the dialog is created in an early state (18x replied) - it's a per dialog type.

    • DLGCB_RESPONSE_FWDED - called when the dialog matches a reply to the initial INVITE request - it's a per dialog type.

    • DLGCB_RESPONSE_WITHIN - called when the dialog matches a reply to a subsequent in dialog request - it's a per dialog type.

    • DLGCB_RPC_CONTEXT - called when the rpc dlg_list_ctx command is invoked - it's a per dialog type.

    • DLGCB_SPIRALED - called when the dialog matches a spiraling request - it's a per dialog type.

    • DLGCB_DESTROY

  • dialog_cb cb - callback function to be called. Prototype is: void (dialog_cb) (struct dlg_cell* dlg, int type, struct dlg_cb_params * params);

  • void *param - parameter to be passed to the callback function.

  • param_free callback_param_free - callback function to be called to free the param. Prototype is: void (param_free_cb) (void *param);

1.2.  terminate_dlg (dlg, hdrs)

Terminate a Dialog

Meaning of parameters is as follows:

  • struct dlg_cell* dlg - dialog to terminate.

  • str* hdrs - string containing extra headers (full format) to be added to the BYE requests of the dialog.

Chapter 3. Frequently Asked Questions

3.1. What happened with “use_tight_match” parameter?
3.2. Where can I find more about Kamailio?
3.3. Where can I post a question about this module?
3.4. How can I report a bug?

3.1.

What happened with use_tight_match parameter?

The parameter was removed with version 1.3 as the option of tight matching became mandatory and not configurable. Now, the tight matching is done all the time (when using DID matching).

3.2.

Where can I find more about Kamailio?

Take a look at https://www.kamailio.org/.

3.3.

Where can I post a question about this module?

First at all check if your question was already answered on one of our mailing lists:

E-mails regarding any stable Kamailio release should be sent to and e-mails regarding development versions should be sent to .

3.4.

How can I report a bug?

Please follow the guidelines provided at: https://github.com/kamailio/kamailio/issues.