dialog Module


Table of Contents

1. Admin Guide
1.1. Overview
1.2. How it works
1.3. Dialog profiling
1.4. Dialog clustering
1.5. Dependencies
1.5.1. OpenSIPS Modules
1.5.2. External Libraries or Applications
1.6. Exported Parameters
1.6.1. enable_stats (integer)
1.6.2. hash_size (integer)
1.6.3. log_profile_hash_size (integer)
1.6.4. rr_param (string)
1.6.5. default_timeout (integer)
1.6.6. dlg_extra_hdrs (string)
1.6.7. dlg_match_mode (integer)
1.6.8. db_url (string)
1.6.9. db_mode (integer)
1.6.10. db_update_period (integer)
1.6.11. options_ping_interval (integer)
1.6.12. reinvite_ping_interval (integer)
1.6.13. table_name (string)
1.6.14. call_id_column (string)
1.6.15. from_uri_column (string)
1.6.16. from_tag_column (string)
1.6.17. to_uri_column (string)
1.6.18. to_tag_column (string)
1.6.19. from_cseq_column (string)
1.6.20. to_cseq_column (string)
1.6.21. from_route_column (string)
1.6.22. to_route_column (string)
1.6.23. from_contact_column (string)
1.6.24. to_contact_column (string)
1.6.25. from_sock_column (string)
1.6.26. to_sock_column (string)
1.6.27. dlg_id_column (string)
1.6.28. state_column (string)
1.6.29. start_time_column (string)
1.6.30. timeout_column (string)
1.6.31. profiles_column (string)
1.6.32. vars_column (string)
1.6.33. sflags_column (string)
1.6.34. mflags_column (string)
1.6.35. flags_column (string)
1.6.36. profiles_with_value (string)
1.6.37. profiles_no_value (string)
1.6.38. db_flush_vals_profiles (int)
1.6.39. timer_bulk_del_no (int)
1.6.40. race_condition_timeout (int)
1.6.41. cachedb_url (string)
1.6.42. profile_value_prefix (string)
1.6.43. profile_no_value_prefix (string)
1.6.44. profile_size_prefix (string)
1.6.45. profile_timeout (int)
1.6.46. dialog_replication_cluster (int)
1.6.47. profile_replication_cluster (int)
1.6.48. replicate_profiles_buffer (string)
1.6.49. replicate_profiles_check (string)
1.6.50. replicate_profiles_timer (string)
1.6.51. replicate_profiles_expire (string)
1.6.52. cluster_auto_sync (string)
1.7. Exported Functions
1.7.1. create_dialog([flags])
1.7.2. match_dialog([dlg_match_mode])
1.7.3. validate_dialog()
1.7.4. fix_route_dialog()
1.7.5. get_dialog_info(attr,avp,key,key_val,no_dlgs)
1.7.6. get_dialog_vals(names,vals,callid)
1.7.7. get_dialogs_by_val(name,value,out_avp,out_dlg_no)
1.7.8. get_dialogs_by_profile(name,value,out_avp,out_dlg_no)
1.7.9. load_dialog_ctx( dialog [, id_type])
1.7.10. unload_dialog_ctx()
1.7.11. set_dlg_profile(profile,[value])
1.7.12. unset_dlg_profile(profile,[value])
1.7.13. is_in_profile(profile,[value])
1.7.14. get_profile_size(profile,[value],size)
1.7.15. set_dlg_flag(idx)
1.7.16. test_and_set_dlg_flag(idx, value)
1.7.17. reset_dlg_flag(idx)
1.7.18. is_dlg_flag_set(idx)
1.7.19. store_dlg_value(name,val)
1.7.20. fetch_dlg_value(name,val)
1.7.21. set_dlg_sharing_tag(tag_name)
1.7.22. dlg_on_answer([route_name])
1.7.23. dlg_on_timeout([route_name])
1.7.24. dlg_on_hangup([route_name])
1.7.25. dlg_send_sequential(method, leg, [, body] [, content-type] [, headers])
1.8. Exported Statistics
1.8.1. active_dialogs
1.8.2. early_dialogs
1.8.3. processed_dialogs
1.8.4. expired_dialogs
1.8.5. failed_dialogs
1.8.6. create_sent
1.8.7. update_sent
1.8.8. delete_sent
1.8.9. create_recv
1.8.10. update_recv
1.8.11. delete_recv
1.9. Exported MI Functions
1.9.1. dlg_list
1.9.2. dlg_list_ctx
1.9.3. dlg_end_dlg
1.9.4. profile_get_size
1.9.5. profile_list_dlgs
1.9.6. profile_get_values
1.9.7. profile_end_dlgs
1.9.8. dlg_db_sync
1.9.9. dlg_cluster_sync
1.9.10. dlg_restore_db
1.9.11. list_all_profiles
1.9.12. dlg_push_var
1.9.13. dlg_send_sequential
1.10. Exported Pseudo-Variables
1.10.1. $DLG_count
1.10.2. $DLG_status
1.10.3. $DLG_lifetime
1.10.4. $DLG_flags
1.10.5. $DLG_dir
1.10.6. $DLG_did
1.10.7. $DLG_end_reason
1.10.8. $DLG_timeout
1.10.9. $DLG_json
1.10.10. $DLG_ctx_json
1.10.11. $dlg_val(name)
1.11. Exported Events
1.11.1. E_DLG_STATE_CHANGED
2. Developer Guide
2.1. Available Functions
2.1.1. register_dlgcb (dialog, type, cb, param, free_param_cb)
3. Frequently Asked Questions
4. Contributors
4.1. By Commit Statistics
4.2. By Commit Activity
5. Documentation
5.1. Contributors

List of Tables

4.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
4.2. Most recently active contributors(1) to this module

List of Examples

1.1. Set enable_stats parameter
1.2. Set hash_size parameter
1.3. Set hash_size parameter
1.4. Set rr_param parameter
1.5. Set default_timeout parameter
1.6. Set dlf_extra_hdrs parameter
1.7. Set dlg_match_mode parameter
1.8. Set db_url parameter
1.9. Set db_mode parameter
1.10. Set db_update_period parameter
1.11. Set options_ping_interval parameter
1.12. Set reinvite_ping_interval parameter
1.13. Set table_name parameter
1.14. Set call_id_column parameter
1.15. Set from_uri_column parameter
1.16. Set from_tag_column parameter
1.17. Set to_uri_column parameter
1.18. Set to_tag_column parameter
1.19. Set from_cseq_column parameter
1.20. Set to_cseq_column parameter
1.21. Set from_route_column parameter
1.22. Set to_route_column parameter
1.23. Set from_contact_column parameter
1.24. Set to_contact_column parameter
1.25. Set from_sock_column parameter
1.26. Set to_sock_column parameter
1.27. Set dlg_id_column parameter
1.28. Set state_column parameter
1.29. Set start_time_column parameter
1.30. Set timeout_column parameter
1.31. Set profiles_column parameter
1.32. Set vars_column parameter
1.33. Set sflags_column parameter
1.34. Set mflags_column parameter
1.35. Set flags_column parameter
1.36. Set profiles_with_value parameter
1.37. Set profiles_no_value parameter
1.38. Set db_flush_vals_profiles parameter
1.39. Set timer_bulk_del_no parameter
1.40. Set race_condition_timeout parameter
1.41. Set cachedb_url parameter
1.42. Set profile_value_prefix parameter
1.43. Set profile_no_value_prefix parameter
1.44. Set profile_size_prefix parameter
1.45. Set profile_timeout parameter
1.46. Set dialog_replication_cluster parameter
1.47. Set profile_replication_cluster parameter
1.48. Set replicate_profiles_buffer parameter
1.49. Set replicate_profiles_check parameter
1.50. Set replicate_profiles_timer parameter
1.51. Set replicate_profiles_expire parameter
1.52. Set cluster_auto_sync parameter
1.53. create_dialog() usage
1.54. match_dialog() usage
1.55. validate_dialog() usage
1.56. fix_route_dialog() usage
1.57. get_dialog_info usage
1.58. get_dialog_vals usage
1.59. get_dialog_vals usage
1.60. get_dialog_vals usage
1.61. load_dialog_ctx usage
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. set_dlg_flag usage
1.67. test_and_set_dlg_flag usage
1.68. reset_dlg_flag usage
1.69. is_dlg_flag_set usage
1.70. store_dlg_value usage
1.71. fetch_dlg_value usage
1.72. set_dlg_sharing_tag usage
1.73. dlg_on_answer usage
1.74. dlg_on_timeout usage
1.75. dlg_on_hangup usage
1.76. dlg_send_sequential usage to convert DTMF codes

Chapter 1. Admin Guide

1.1. Overview

The dialog module provides dialog awareness to the OpenSIPS proxy. Its functionality is to keep trace of the current dialogs, to offer information about them (like how many dialogs are active).

Aside tracking, the dialog module offers functionalities like flags and attributes per dialog (persistent data across dialog), dialog profiling and dialog termination (on timeout base or external triggered).

The module, via an internal API, also provide the foundation to build on top of it more complex dialog-based functionalities via other OpenSIPS modules.

1.2. How it works

To create the dialog associated with an initial request, you must call the create_dialog() function, with or without parameter.

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 - default_timeout) and custom timeout (see $DLG_timeout - $DLG_timeout).

1.3. Dialog profiling

Dialog profiling is a mechanism that helps in classifying, sorting and keeping trace of certain types of dialogs, using whatever properties of the dialog (like caller, destination, type of calls, etc). Dialogs can be dynamically added in different (and several) profile tables - logically, each profile table can have a special meaning (like dialogs outside the domain, dialogs terminated to PSTN, etc).

There are two types of profiles:

  • with no value - a dialog simply belongs to a profile. (like outbound calls profile). There is no other additional information to describe the dialog's belonging to the profile;

  • with value - a dialog belongs to a profile having a certain value (like in caller profile, where the value is the caller ID). The belonging of the dialog to the profile is strictly related to the value.

A dialog can be added to multiple profiles in 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.

Dialog profiles can also be used in distributed systems, using the OpenSIPS CacheDB Interface or the clusterer module. This feature allows you to share dialog profile information with multiple OpenSIPS instaces that use the same CacheDB backend or are part of an OpenSIPS cluster. In order to do that, the cachedb_url or profile_replication_cluster parameters must be defined. Also, the profile must be marked as shared, by adding one of the '/s' or '/b' suffixes to the name of the profile in the profiles_with_value or profiles_no_value parameters.

1.4. Dialog clustering

Dialog replication is a mechanism used to mirror all dialog changes taking place in one OpenSIPS instance to one or multiple other instances. The process is simplified by using the clusterer module which facilitates the management of a cluster of OpenSIPS nodes and the sending of replication-related BIN packets (binary-encoded, using proto_bin). This feature is useful in achieving High Availability and/or Load Balancing for ongoing calls.

Configuring both receival and sending of dialog replication packets is trivial and can be done by using the dialog_replication_cluster parameter. But in addition to just sharing data, in order to properly cluster dialogs you will need to manage which node in the cluster is doing certain actions on certain dialogs using the sharing tags mechanism. For details and configuration examples on how this would work in different usage scenarios, see this article.

The following actions will not be performed for a dialog marked with a sharing tag that is in the "backup" state:

  • sending Re-Invite or OPTIONS pings to end-points

  • generating BYE requests or any other actions(like producing CDRs) upon dialog expiration

  • sending replication packets on dialog events(update, delete)

  • counting the dialog in the profiles that it belongs; only if profile replication is also enabled

In addition to the event-driven replication, an OpenSIPS instance will first try to learn all the dialog information from antoher node in the cluster at startup. The data synchronization mechanism requires defining one of the nodes in the cluster as a "seed" node. See the clusterer module for details on how to do this and why is it needed.

In the context of dialog replication, using a database as a failsafe for obtaining restart persistency for dialog data is useful in case all nodes in the cluster are down. This approach makes the most sense if a separate, local DB is used for each node in the cluster. Dialogs loaded from the database at startup, which are not reconfirmed through syncing, are dropped and also deleted from the database once the sync from cluster is complete.

Also configuring profile replication via the profile_replication_cluster parameter is not necessary when dialog replication is already configured. The profile information is included in the dialog updates sent in the dialog replication cluster. The profiles must still be marked for sharing though in the profiles_with_value or profiles_no_value parameters.

A scenario were both profile and dialog replication should be configured is when a platform has multiple POPs, where separate dialog replication clusters are configured for HA purposes, and a cluster for globally shared profiles is also required. In this case, proper counting for dialogs is ensured by using the sharing tags mechanism(in order to avoid counting each dialog twice, both on the active and backup node for that dialog).

1.5. Dependencies

1.5.1. OpenSIPS Modules

The following modules must be loaded before this module:

  • TM - Transaction module

  • RR - Record-Route module, optional, if Dialog ID matching is used in non Topo Hiding cases

  • clusterer - if replication_cluster parameter is set (contact replication via clusterer module)

1.5.2. External Libraries or Applications

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

  • None.

1.6. Exported Parameters

1.6.1. enable_stats (integer)

If the statistics support should be enabled or not. Via statistic 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)
...

1.6.2. 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 2 number.

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

Default value is 4096.

Example 1.2. Set hash_size parameter

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

1.6.3. log_profile_hash_size (integer)

The size of the hash table internally used to store profile->dialog associations. A larger table can provide more parallel operations but consumes more memory. The hash size is provided as the base 2 logarithm(e.g. log_profile_hash_size =4 means the table has 2^4 entries).

Default value is 4.

Example 1.3. Set hash_size parameter

...
modparam("dialog", "log_profile_hash_size", 5) #set a table size of 32
...

1.6.4. rr_param (string)

Name of the Record-Route parameter to be added with the dialog cookie. It is used for fast dialog matching of the sequential requests.

Default value is did.

Example 1.4. Set rr_param parameter

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

1.6.5. default_timeout (integer)

The default dialog timeout (in seconds) if no custom one is set.

Default value is 43200 (12 hours).

Example 1.5. Set default_timeout parameter

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

1.6.6. dlg_extra_hdrs (string)

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

Default value is NULL.

Example 1.6. Set dlf_extra_hdrs parameter

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

1.6.7. dlg_match_mode (integer)

How the seqential requests should be matched against the known dialogs. The modes are a combination between matching based on a cookie (DID) stored as cookie in Record-Route header and the matching based on SIP elements (as in RFC3261).

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 fallback 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 1 (DID_FALLBACK).

NOTE that if you have call looping on your OpenSIPS server (passing more than once through the same OpenSIPS instance), it is strongly suggested to use only DID_ONLY mode, as the SIP based matching will have an undefined behavior - from SIP perspective, a sequential dialog will match all the loops of the call, as the Call-ID, To and From TAGs are the same.

Example 1.7. Set dlg_match_mode parameter

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

1.6.8. db_url (string)

If you want to store the information about the dialogs in a database a database url must be specified.

Default value is mysql://opensips:opensipsrw@localhost/opensips.

Example 1.8. Set db_url parameter

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

1.6.9. db_mode (integer)

Describe how to push into the DB the dialogs' information from memory.

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 the 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 1.9. Set db_mode parameter

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

1.6.10. db_update_period (integer)

The interval (seconds) at which to update dialogs' information if you chose to store the dialogs' info at a given interval. A too short interval will generate intensive database operations, a too large one will not notice short dialogs.

Default value is 60.

Example 1.10. Set db_update_period parameter

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

1.6.11. options_ping_interval (integer)

The interval (seconds) at which OpenSIPS will generate in-dialog OPTIONS pings for one or both of the involved parties.

Default value is 30.

Example 1.11. Set options_ping_interval parameter

...
modparam("dialog", "options_ping_interval", 20)
...

1.6.12. reinvite_ping_interval (integer)

The interval (seconds) at which OpenSIPS will generate in-dialog Re-INVITE pings for one or both of the involved parties.

Important: the ping timeout detection is performed every time this interval ticks, not when the re-INVITE transaction times out! Consequently, please make sure that the timeouts for re-INVITE transactions (e.g. the "fr_timeout" modparam of the "tm" module or its $T_fr_timeout variable) are always lower than the value of this parameter! Failing to ensure this ordering of timeouts may possibly lead to re-INVITE pings never ending a disconnected dialog due to pings getting retried before getting a chance to properly time out.

Default value is 300.

Example 1.12. Set reinvite_ping_interval parameter

...
modparam("dialog", "reinvite_ping_interval", 600)
...

1.6.13. table_name (string)

If you want to store the information about the dialogs in a database a table name must be specified.

Default value is dialog.

Example 1.13. Set table_name parameter

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

1.6.14. call_id_column (string)

The column's name in the database to store the dialogs' callid.

Default value is callid.

Example 1.14. Set call_id_column parameter

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

1.6.15. from_uri_column (string)

The column's name in the database to store the caller's sip address.

Default value is from_uri.

Example 1.15. Set from_uri_column parameter

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

1.6.16. from_tag_column (string)

The column's name in the database to store the From tag from the Invite request.

Default value is from_tag.

Example 1.16. Set from_tag_column parameter

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

1.6.17. to_uri_column (string)

The column's name in the database to store the calee's sip address.

Default value is to_uri.

Example 1.17. Set to_uri_column parameter

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

1.6.18. to_tag_column (string)

The column's name in the database to store the To tag from the 200 OK response to the Invite request, if present.

Default value is to_tag.

Example 1.18. Set to_tag_column parameter

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

1.6.19. from_cseq_column (string)

The column's name in the database to store the cseq from caller side.

Default value is caller_cseq.

Example 1.19. Set from_cseq_column parameter

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

1.6.20. to_cseq_column (string)

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

Default value is callee_cseq.

Example 1.20. Set to_cseq_column parameter

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

1.6.21. from_route_column (string)

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

Default value is caller_route_set.

Example 1.21. Set from_route_column parameter

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

1.6.22. to_route_column (string)

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

Default value is callee_route_set.

Example 1.22. Set to_route_column parameter

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

1.6.23. from_contact_column (string)

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

Default value is caller_contact.

Example 1.23. Set from_contact_column parameter

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

1.6.24. to_contact_column (string)

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

Default value is callee_contact.

Example 1.24. Set to_contact_column parameter

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

1.6.25. from_sock_column (string)

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

Default value is caller_sock.

Example 1.25. Set from_sock_column parameter

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

1.6.26. to_sock_column (string)

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

Default value is callee_sock.

Example 1.26. Set to_sock_column parameter

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

1.6.27. dlg_id_column (string)

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

Default value is dlg_id.

Example 1.27. Set dlg_id_column parameter

...
modparam("dialog", "dlg_id_column", "dlg_id_c_name")
...

1.6.28. state_column (string)

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

Default value is state.

Example 1.28. Set state_column parameter

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

1.6.29. start_time_column (string)

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

Default value is start_time.

Example 1.29. Set start_time_column parameter

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

1.6.30. timeout_column (string)

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

Default value is timeout.

Example 1.30. Set timeout_column parameter

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

1.6.31. profiles_column (string)

The column's name in the database to store the dialogs' profiles.

Default value is profiles.

Example 1.31. Set profiles_column parameter

...
modparam("dialog", "profiles_column", "profiles_c_name")
...

1.6.32. vars_column (string)

The column's name in the database to store the dialogs' vars.

Default value is vars.

Example 1.32. Set vars_column parameter

...
modparam("dialog", "vars_column", "vars_c_name")
...

1.6.33. sflags_column (string)

The column's name in the database to store the dialogs' script flags.

Default value is script_flags.

Example 1.33. Set sflags_column parameter

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

1.6.34. mflags_column (string)

The column's name in the database to store the dialogs' module flags.

Default value is module_flags.

Example 1.34. Set mflags_column parameter

...
modparam("dialog", "mflags_column", "mflags_c_name")
...

1.6.35. flags_column (string)

The column's name in the database to store the dialogs' flags.

Default value is flags.

Example 1.35. Set flags_column parameter

...
modparam("dialog", "flags_column", "flags_c_name")
...

1.6.36. profiles_with_value (string)

List of names (alphanumerical) for profiles with values. Flags /b or /s allow sharing profiles between OpenSIPS instances using the clusterer module or a CacheDB backend, respectively.

Default value is empty.

Example 1.36. Set profiles_with_value parameter

...
modparam("dialog", "profiles_with_value", "callerCC; gatewayCC; clientChannels/s; codecUsed/b;")
...

1.6.37. profiles_no_value (string)

List of names (alphanumerical) for profiles without values. Flags /b or /s allow sharing profiles between OpenSIPS instances using the clusterer module or a CacheDB backend, respectively.

Default value is empty.

Example 1.37. Set profiles_no_value parameter

...
modparam("dialog", "profiles_no_value", "inbound ; outbound ; shared/s; repl/b;")
...

1.6.38. db_flush_vals_profiles (int)

Pushes dialog values, profiles and flags into the database along with other dialog state information (see db_mode 1 and 2).

Default value is empty.

Example 1.38. Set db_flush_vals_profiles parameter

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

1.6.39. timer_bulk_del_no (int)

The number of dialogs that should be attempted to be deleted at the same time ( a single query ) from the DB back-end.

Default value is 1.

Example 1.39. Set timer_bulk_del_no parameter

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

1.6.40. race_condition_timeout (int)

If dialog is created using the 'E' flag, and a SIP Race condition happens, then the dialog will be terminated after 'race_condition_timeout' seconds. Currently, the only supported race conditions are (200OK vs CANCEL) and (early BYE vs 200OK)

Default value is 5 seconds.

Example 1.40. Set race_condition_timeout parameter

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

1.6.41. cachedb_url (string)

Enables distributed dialog profiles and specifies the backend that should be used by the CacheDB interface.

Default value is empty.

Example 1.41. Set cachedb_url parameter

...
modparam("dialog", "cachedb_url", "redis://127.0.0.1:6379")
...

1.6.42. profile_value_prefix (string)

Specifies what prefix should be added to the profiles with value when they are inserted into CacheDB backed. This is only used when distributed profiles are enabled.

Default value is dlg_val_.

Example 1.42. Set profile_value_prefix parameter

...
modparam("dialog", "profile_value_prefix", "dlgv_")
...

1.6.43. profile_no_value_prefix (string)

Specifies what prefix should be added to the profiles without value when they are inserted into CacheDB backed. This is only used when distributed profiles are enabled.

Default value is dlg_noval_.

Example 1.43. Set profile_no_value_prefix parameter

...
modparam("dialog", "profile_no_value_prefix", "dlgnv_")
...

1.6.44. profile_size_prefix (string)

Specifies what prefix should be added to the entity that holds the profiles with value size in CacheDB backed. This is only used when distributed profiles are enabled.

Default value is dlg_size_.

Example 1.44. Set profile_size_prefix parameter

...
modparam("dialog", "profile_size_prefix", "dlgs_")
...

1.6.45. profile_timeout (int)

Specifies how long a dialog profile should be kept in the CacheDB until it expires. This is only used when distributed profiles are enabled.

Default value is 86400.

Example 1.45. Set profile_timeout parameter

...
modparam("dialog", "profile_timeout", "43200")
...

1.6.46. dialog_replication_cluster (int)

Specifies the cluster ID for dialog replication using the clusterer module. This enables sending and receiving all the dialog-related events (creation, update and deletion) in the cluster.

Default value is 0 (no replication).

Example 1.46. Set dialog_replication_cluster parameter

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

1.6.47. profile_replication_cluster (int)

Specifies the cluster ID for profile replication using the clusterer module. This enables sending and receiving the profile information (value, dialog count) in the cluster.

Default value is 0 (no replication).

Example 1.47. Set profile_replication_cluster parameter

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

1.6.48. replicate_profiles_buffer (string)

Used to specify the length of the buffer used by the binary replication, in bytes. Usually this should be big enough to hold as much data as possible, but small enough to avoid UDP fragmentation. The recommended value is the smallest MTU between all the replication instances.

Default value is 1400 bytes.

Example 1.48. Set replicate_profiles_buffer parameter

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

1.6.49. replicate_profiles_check (string)

Timer in seconds, used to specify how often the module should check whether old, replicated profiles values are obsolete and should be removed. should replicate its profiles to the other instances.

Default value is 10 s.

Example 1.49. Set replicate_profiles_check parameter

...
modparam("dialog", "replicate_profiles_check", 100)
...

1.6.50. replicate_profiles_timer (string)

Timer in milliseconds, used to specify how often the module should replicate its profiles to the other instances.

Default value is 200 ms.

Example 1.50. Set replicate_profiles_timer parameter

...
modparam("dialog", "replicate_profiles_timer", 100)
...

1.6.51. replicate_profiles_expire (string)

Timer in seconds, used to specify when the profiles counters received from a different instance should no longer be taken into account. This is used to prevent obsolete values, in case an instance stops replicating its counters.

Default value is 10 s.

Example 1.51. Set replicate_profiles_expire parameter

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

1.6.52. cluster_auto_sync (string)

Specifies whether to automatically issue a sync request (for dialogs marked with a sharing tag in backup state) when a node becomes reachable. A value of 1 means enabled and 0 disabled.

Default value is 1 (enabled).

Example 1.52. Set cluster_auto_sync parameter

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

1.7. Exported Functions

1.7.1.  create_dialog([flags])

The function creats the dialog for the currently processed request. The request must be an initial request. Optionally,the function also receives a string parameter, which specifies special behavior to be done for the current dialog.

Parameters:

  • flags (string, optional) Possible values here are :

    • B - Upon reaching dialog lifetime, BYEs will be triggered both ways

    • P - Ping caller side with OPTIONS messages, once every options_ping_interval seconds

    • p - Ping callee side with OPTIONS messages, once every options_ping_interval seconds

    • R - Ping caller side with RE-INVITE messages, once every reinvite_ping_interval seconds

    • r - Ping callee side with RE-INVITE messages, once every reinvite_ping_interval seconds

    • E - Upon detecting a SIP Race condition (see RFC 5407), end the call after race_condition_timeout seconds

    Multiple string flags can be used at the same time, ie. passing "BPp" flags will enable all 3 flags.

NOTE: both RE-INVITE and OPTIONS pinging cannot be enabled at the same time for a single dialog leg. If both flags ("PR" or "pr") are provided only RE-INVITE pinging will be used.

The function returns true if the dialog was successfully created or if the dialog was previously created.

This function can be used from REQUEST_ROUTE.

Example 1.53. create_dialog() usage

...
create_dialog();
...
#ping caller
create_dialog("P");
...
#ping caller and callee
create_dialog("Pp");

#bye on timeout
create_dialog("B");
...

1.7.2.  match_dialog([dlg_match_mode])

This function is to be used to match a sequential (in-dialog) request to an ongoing dialog.

By default, dialog matching is performed according to the dlg_match_mode module parameter. A specific matching mode may be enforced by specifying the optional "dlg_match_mode" parameter. Possible values for this parameter are "DID_ONLY", "DID_FALLBACK" and "DID_NONE".

As sequential requests are automatically matched to the dialog when doing "loose_route()" from script, this function is intended to: (A) control the place in your script where the dialog matching is done and (B) to cope with bogus sequential requests that do not have Route headers, so they are not handled by loose_route().

Parameters:

  • dlg_match_mode (string, optional)

The function returns true if a dialog exists for the request.

This function can be used from REQUEST_ROUTE.

Example 1.54. match_dialog() usage

...
    if (has_totag()) {
        loose_route();

        # example 1: match according to dlg_match_mode
        if ($DLG_status == NULL && !match_dialog())
            xlog("cannot match request to a dialog\n");

        # example 2: override dlg_match_mode
        if ($DLG_status == NULL && !match_dialog("DID_FALLBACK"))
            xlog("cannot match request to a dialog\n");
    }
...

1.7.3.  validate_dialog()

The function checks the current received requests against the dialog (internal data) it belongs to. Performing several tests, the function will help to detect the bogus injected in-dialog requests (like malicious BYEs).

The performed tests are related to CSEQ sequence checking and routing information checking (contact and route set).

The function returns true if a dialog exists for the request and if the request is valid (according to dialog data). If the request is invalid, the following return codes are returned :

  • -1 - invalid cseq

  • -2 - invalid remote target

  • -3 - invalid route set

  • -4 - other errors ( parsing, no dlg, etc )

This function can be used from REQUEST_ROUTE.

Example 1.55. validate_dialog() usage

...
    if (has_totag()) {
        loose_route();
        if ($DLG_status!=NULL && !validate_dialog() ) {
            xlog(" in-dialog bogus request \n");
        } else {
            xlog(" in-dialog valid request - $DLG_dir !\n");
        }
    }
...

1.7.4.  fix_route_dialog()

The function forces an in dialog SIP message to contain the ruri, route headers and dst_uri, as specified by the internal data of the dialog it belongs to. The function will prevent the existence of bogus injected in-dialog requests ( like malicious BYEs )

This function can be used from REQUEST_ROUTE.

Example 1.56. fix_route_dialog() usage

...
    if (has_totag()) {
        loose_route();
        if ($DLG_status!=NULL)
            if (!validate_dialog())
                fix_route_dialog();
    }
...

1.7.5.  get_dialog_info(attr,avp,key,key_val,no_dlgs)

The function extracts a dialog value from another dialog. It first searches through all existing (ongoing) dialogs for all dialogs that have a dialog variable named "key" with the value "key_val" (so a dialog where $dlg_val(key)=="key_val"). If found, it returns the value of the dialog variable "attr" from all the founds dialog in the "avp" pseudo-variable, otherwise nothing is written in "avp", and a negative error code is returned.

NOTE: the function does not require to be called in the context of a dialog - you can use it whenever / whereever for searching for other dialogs.

Meaning of the parameters is as follows:

  • attr (string) - the name of the dialog variable (from the found dialog) to be returned;

  • avp (var) - an avp where to store the values of the "attr" dialog variable. Since the function checks through all dialogs, this needs to be an actual AVP in order to support pushing values from all matched dialogs.

  • key (string) - name of a dialog variable to be used a search key (when looking after the target dialog)

  • key_val (string) - the value of the dialog variable that is used as key in searching the target dialog.

  • no_dlgs (var) - the total number of dialogs containing the key variable

This function can be used from ALL ROUTES.

Example 1.57. get_dialog_info usage

...
if ( get_dialog_info("callee",$avp(callee_array),"caller",$fu,$var(dlg_no)) ) {
	xlog("caller $fu has $var(dlg_no) other ongoing calls, talking with :");	
	$var(it) = 0;
	while ($var(it) < $var(dlg_no)) {
		$var(current_callee) = $(avp(callee_array)[$var(it)]);
		xlog(" $var(current_callee) ");
		$var(it) = $var(it) + 1;
	}

	xlog("\n");
}

# create dialog for current call and place the caller and callee attributes
create_dialog();
$dlg_val(caller) = $fu;
$dlg_val(callee) = $ru;
...

1.7.6.  get_dialog_vals(names,vals,callid)

The function fetches all the dialog variables of another dialog. It first searches through all existing (ongoing) dialogs based on the given SIP CallID. If found, it returns all the dialog variables as two parallel arrays of names and values (using the given variables "names" and "vals"). As these variables have to hold arrays, they must be AVPs.

NOTE: the function does not require to be called in the context of a dialog - you can use it whenever / whereever for searching for other dialogs.

Meaning of the parameters is as follows:

  • names (var) - an AVP variable to hold all the names of the variables from the found dialog.

  • vals (var) - an AVP variable to hold all the values of the variables from the found dialog.

  • callid (string) - the callid of a dialog to be searched (and have the variables fetched).

This function can be used from any type of route.

Example 1.58. get_dialog_vals usage

...
if ( get_dialog_vals($avp(d_names),$avp(d_vals),$var(callid)) ) {
	xlog("the call $var(callid) has the variables:\n);
	$var(i) = 0;
	while ( $(avp(d_names)[$var(i)])!=NULL ) {
		xlog("var $var(i) is $(avp(d_names)[$var(i)])='$(avp(d_vals)[$var(i)])'\n");
		$var(i) = $var(i) + 1;
	}
}
...

1.7.7.  get_dialogs_by_val(name,value,out_avp,out_dlg_no)

The function looks up through the whole dialog table for dialogs containing a $dlg_val with the provided name and value, and returns all the $DLG_ctx_json variables for the matched dialogs, storing them in the provided out_avp. The total number of matched dialogs is returned in the out_dlgs_no variable

NOTE: the function does not require to be called in the context of a dialog - you can use it whenever / whereever for searching for other dialogs.

Meaning of the parameters is as follows:

  • name (string) - the name of the dialog variable used for the lookup

  • value (string) - the value of the above dialog val

  • out_avp (var) - the AVP which will be populated will the dialog JSONs for all the matched calls

  • dlg_no (var) - the out var which will contain the total number of matched dialogs

This function can be used from any type of route.

Example 1.59. get_dialog_vals usage

...
if ( get_dialogs_by_val("caller",$fU,$avp(dlg_jsons),$avp(dlg_no)) ) {
	xlog("Caller $fU has $avp(dlg_no) other calls \n);
	$var(i) = 0;
	while ( $(avp(dlg_jsons)[$var(i)])!=NULL ) {
		$json(dlg_info) := $(avp(dlg_jsons)[$var(i)]); 
		# fetch any info for the above call and process it
		$var(i) = $var(i) + 1;
	}
}
...

1.7.8.  get_dialogs_by_profile(name,value,out_avp,out_dlg_no)

The function looks up through the whole dialog table for dialogs configured to be within the provided dialog profile name, and optionally with the provided profile value. The function returns all the $DLG_ctx_json variables for the matched dialogs, storing them in the provided out_avp. The total number of matched dialogs is returned in the out_dlgs_no variable

NOTE: the function does not require to be called in the context of a dialog - you can use it whenever / whereever for searching for other dialogs.

Meaning of the parameters is as follows:

  • name (string) - the name of the dialog profile used for the lookup

  • value (string) - the value of the above dialog profile ( optional )

  • out_avp (var) - the AVP which will be populated will the dialog JSONs for all the matched calls

  • dlg_no (var) - the out var which will contain the total number of matched dialogs

This function can be used from any type of route.

Example 1.60. get_dialog_vals usage

...
if ( get_dialogs_by_profile("caller",$fU,$avp(dlg_jsons),$avp(dlg_no)) ) {
	xlog("Caller $fU has $avp(dlg_no) other calls \n);
	$var(i) = 0;
	while ( $(avp(dlg_jsons)[$var(i)])!=NULL ) {
		$json(dlg_info) := $(avp(dlg_jsons)[$var(i)]); 
		# fetch any info for the above call and process it
		$var(i) = $var(i) + 1;
	}
}
...

1.7.9.  load_dialog_ctx( dialog [, id_type])

The function loads and switches to the context of the given dialog. The context of a dialog is given by the dialog flags, variables, profiles and any other value/state related to the dialog. By switching to the context of another dialog, you will see at the script level, by default, all the data from the new dialog.

NOTE: you cannot perform a new load until doing an unload - no nested loadings are possible.

Meaning of the parameters is as follows:

  • dialog (string) - the identifier of the dialog to be loaded, it may be a SIP Call-ID or a Dialog ID.

  • id_type (string,optional) - what kind of dialog identified was used in the first parameter. It can be callid (SIP Call-ID) or did (internal Dialog ID). By default callid will be assumed.

This function can be used from any type of route.

Example 1.61. load_dialog_ctx usage

...
if (load_dialog_ctx("$var(callid)")) {
	xlog("The dialog '$var(callid)' already has a duration "
	     "of $DLG_lifetime seconds\n");
	if (is_in_profile("inboundCall"))
		xlog("this dialog is an inbound call\n");
	unload_dialog_ctx();
}
...

1.7.10.  unload_dialog_ctx()

The function off-loads the loaded context of another dialog, exposing whatever dialog context was present before doing the load.

NOTE: you MUST perform from script an explicit unload for each load you did, otherwise the loaded dialog will remain hanged for ever.

This function can be used from any type of route.

For usage example, see the load_dialog_ctx()

1.7.11.  set_dlg_profile(profile,[value])

Inserts the current dialog into a profile. Note that if the profile does not support values, this will be silently discarded. A dialog may be inserted in the same profile multiple times.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

Meaning of the parameters is as follows:

  • profile (string) - name of the profile to be added to.

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

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

1.7.12.  unset_dlg_profile(profile,[value])

Removes the current dialog from a profile.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

Meaning of the parameters is as follows:

  • profile (string) - name of the profile to be removed from.

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

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

Example 1.63. unset_dlg_profile usage

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

1.7.13.  is_in_profile(profile,[value])

Checks if the current dialog belongs to a profile. If the profile supports values, the check can be reinforced to take into account a specific value - if the dialog was inserted into the profile for a specific value. If no value is passed, only simply belonging of the dialog to the profile is checked. Note that if the profile does not support values, this will be silently discarded.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

Meaning of the parameters is as follows:

  • profile (string) - name of the profile to be checked against.

  • value (string. optional) - string value to toughen the check.

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("inboundCall")) {
	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");
}
...

1.7.14.  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 - how many dialogs were inserted into the profile with a specific value. If not value is passed, only simply belonging of the dialog to the profile is checked. Note that the profile does not supports values, this will be silently discarded.

Meaning of the parameters is as follows:

  • profile (string) - name of the profile to get the size for.

  • value (string, optional) - string value to toughen the check.

  • size (var) - 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

modparam("dialog", "profiles_no_value", "inboundCalls")
modparam("dialog", "profiles_with_value", "caller")
...
get_profile_size("inboundCalls",,$var(size));
xlog("inboundCalls: $var(size)\n");
...
get_profile_size("caller", $fu, $var(size));
xlog("currently, the user $fu has $var(size) active outgoing calls\n");
...

1.7.15.  set_dlg_flag(idx)

Sets the dialog flag index idx to true. The dialog flags are dialog persistent and they can be accessed (set and test) for all requests belonging to the dialog.

Parameters:

  • idx (int) - The flag index can be between 0 and 31.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

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

Example 1.66. set_dlg_flag usage

...
set_dlg_flag(3);
...

1.7.16.  test_and_set_dlg_flag(idx, value)

Atomically checks if the dialog flag index idx is equal to value. If true, changes the value with the opposite one. This operation is done under the dialog lock.

  • idx (int) - The flag index can be between 0 and 31.

  • value (int) - The value should be 0 (false) or 1 (true).

NOTE: the dialog must be created before using this function (use create_dialog() function before).

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

Example 1.67. test_and_set_dlg_flag usage

...
test_and_set_dlg_flag(3, 0);
...

1.7.17.  reset_dlg_flag(idx)

Resets the dialog flag index idx to false. The dialog flags are dialog persistent and they can be accessed (set and test) for all requests belonging to the dialog.

Parameters:

  • idx (int) - The flag index can be between 0 and 31.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

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

Example 1.68. reset_dlg_flag usage

...
reset_dlg_flag(16);
...

1.7.18.  is_dlg_flag_set(idx)

Returns true if the dialog flag index idx is set. The dialog flags are dialog persistent and they can be accessed (set and test) for all requests belonging to the dialog.

Parameters:

  • idx (int) - The flag index can be between 0 and 31.

NOTE: the dialog must be created before using this function (use create_dialog() function before).

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

Example 1.69. is_dlg_flag_set usage

...
if (is_dlg_flag_set(16)) {
	xlog("dialog flag 16 is set\n");
}
...

1.7.19.  store_dlg_value(name,val)

Attaches to the dialog the value val under the name name. The values attached to dialogs are dialog persistent and they can be accessed (read and write) for all requests belonging to the dialog.

Parameters:

  • name (string)

  • val (string)

NOTE: the dialog must be created before using this function (use create_dialog() function before).

Same functionality may be obtain by assigning a value to pseudo variable $dlg_val(name).

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

Example 1.70. store_dlg_value usage

...
store_dlg_value("inv_src_ip",$si);
store_dlg_value("account type","prepaid");
# or
$dlg_val(account_type) = "prepaid";
...

1.7.20.  fetch_dlg_value(name,val)

Fetches from the dialog the value of attribute named name. The values attached to dialogs are dialog persistent and they can be accessed (read and write) for all requests belonging to the dialog.

Parameters:

  • name (string)

  • val (var)

NOTE: the dialog must be created before using this function (use create_dialog() function before).

Same functionality may be obtain by reading the pseudo variable $dlg_val(name).

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

Example 1.71. fetch_dlg_value usage

...
fetch_dlg_value("inv_src_ip",$avp(2));
fetch_dlg_value("account type",$var(account));
# or
$var(account) = $dlg_val(account_type);
...

1.7.21.  set_dlg_sharing_tag(tag_name)

Marks the current dialog with the sharing tag tag_name. From this point on, actions like in-dialog pinging, BYEs on timeout etc. will depend on the tag state(no action in "backup" state, normal operation in "active" state).

For more details see the Dialog clustering chapter.

Parameters:

  • tag_name (string)

NOTE: the dialog must be created before using this function (use create_dialog() function before).

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

Example 1.72. set_dlg_sharing_tag usage

...
set_dlg_sharing_tag("vip1");
...

1.7.22.  dlg_on_answer([route_name])

The function arms a script route to be executed when the current dialog will be later answered. When the route will be executed, the dialog context will be exposed, but with no valid SIP message (just a phony one).

You must use this function AFTER creating the dialog and before the dialog being answered.

If the parameter is missing, the function does a reset of any route previously set; there will be no triggering.

Parameters:

  • route_name (string,optional) - the name of the script route to be executed.

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

Example 1.73. dlg_on_answer usage

...
create_dialog();
dlg_on_answer("dlg_answered");
...
route[dlg_answered] {
	xlog("The dialog $DLG_did was answered\n");
}

1.7.23.  dlg_on_timeout([route_name])

The function arms a script route to be executed when (and if) the current dialog will timeout (as duration). When the route will be executed, the dialog context will be exposed, but with no valid SIP message (just a phony one)

When the route is executed, the dialog is not yet terminated, just its lifetime reached the set limit. In the timeout route you can increase the dialog expiration timeout (and the dialog will continue) or you can let the dialog to be terminated (after the end of this route).

You must use this function AFTER creating the dialog and before the dialog being answered.

You must use this function AFTER creating the dialog and before the dialog being answered.

Parameters:

  • route_name (string,optional) - the name of the script route to be executed.

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

Example 1.74. dlg_on_timeout usage

...
create_dialog();
$DLG_timeout=120;
dlg_on_timeout("dlg_timeout");
...
route[dlg_timeout] {
	xlog("The dialog $DLG_did timed out\n");
	if (_some_prolongation_condition)
		$DLG_timeout = 60; # give it 1 min more
}

1.7.24.  dlg_on_hangup([route_name])

The function arms a script route to be executed when the current dialog will be terminated. When the route will be executed, the dialog context will be exposed, but with no valid SIP message (just a phony one). Note that the dialog will be already terminated and there is nothing you can do about it besides reading data from its context.

You must use this function AFTER creating the dialog and before the dialog being answered.

If the parameter is missing, the function does a reset of any route previously set; there will be no triggering.

Parameters:

  • route_name (string,optional) - the name of the script route to be executed.

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

Example 1.75. dlg_on_hangup usage

...
create_dialog();
dlg_on_hangup("dlg_hangup");
...
route[dlg_hangup] {
	xlog("The dialog $DLG_did terminated after $DLG_lifetime secs\n");
}

1.7.25.  dlg_send_sequential(method, leg, [, body] [, content-type] [, headers])

Used to send an in-dialog request towards one if the dialog's legs. The function assumes that is runs inside a dialog context - if you are running it from a different context (such as an event_route), make sure you first load the dialog context using the load_dialog_ctx() function.

Parameters:

  • method (string) - the method of the request sent.

  • leg (string) - the leg where the request is sent. Must be either caller or callee.

  • body (string, optional) - an optional body sent in the request. If missing, no body is sent.

  • content-type (string, optional) - the content type of the body sent. Make sure you specify this every time you send a request with a body, otherwise there are high changes that your UAC will reject the request.

  • headers (string, optional) - additional headers attached to the request sent.

This function can be used from ANY route.

Example 1.76. dlg_send_sequential usage to convert DTMF codes

...
event_route[E_RTPPROXY_DTMF] {
    if (load_dialog_ctx("$param(id)", "did")) {
        if ($param(stream) == 0) {
            $var(direction) = "callee";
        } else {
            $var(direction) = "caller";
        }
        dlg_send_sequential($var(direction), "INFO",
                "Signal=$param(digit)\nDuration=160",
                "application/dtmf-relay");
        unload_dialog_ctx();
    }
}
...

1.8. Exported Statistics

1.8.1. active_dialogs

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

1.8.2. early_dialogs

Returns the number of early dialogs.

1.8.3. processed_dialogs

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

1.8.4. expired_dialogs

Returns the total number of expired dialogs from the startup.

1.8.5. failed_dialogs

Returns the number of failed dialogs ( dialogs were never established due to whatever reasons - internal error, negative reply, cancelled, etc )

1.8.6. create_sent

Returns the number of replicated dialog create requests send to other OpenSIPS instances.

1.8.7. update_sent

Returns the number of replicated dialog update requests send to other OpenSIPS instances.

1.8.8. delete_sent

Returns the number of replicated dialog delete requests send to other OpenSIPS instances.

1.8.9. create_recv

Returns the number of dialog create events received from other OpenSIPS instances.

1.8.10. update_recv

Returns the number of dialog update events received from other OpenSIPS instances.

1.8.11. delete_recv

Returns the number of dialog delete events received from other OpenSIPS instances.

1.9. Exported MI Functions

1.9.1.  dlg_list

Lists the description of the dialogs (calls). If no parameter is given, all dialogs will be listed. If a dialog identifier is passed as parameter (callid and fromtag), only that dialog will be listed. If a index and conter parameter is passed, it will list only a number of "counter" dialogs starting with index (as offset) - this is used to get only section of dialogs.

Name: dlg_list

Parameters (with dialog idetification):

  • callid (optional) - callid if a single dialog to be listed.

  • from_tag (optional, but cannot be present without the callid parameter) - fromtag (as per initial request) of the dialog to be listed. entry

Parameters (with dialog counting):

  • index - offset where the dialog listing should start.

  • counter - how many dialogs should be listed (starting from the offset)

MI FIFO Command Format:

		## list all ongoing dialogs
		opensips-cli -x mi dlg_list
		## list the dialog by callid and From TAG
		opensips-cli -x mi dlg_list callid=abcdrssfrs122444@192.168.1.1 from_tag=AAdfeEFF33
		## list 10 dialogs, starting from the position 40
		## (in the list of all ongoing dialogs)
		opensips-cli -x mi dlg_list index=40 counter=10
		

1.9.2. 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. This function also prints the dialog's values. In case of binary values, the non-printable chars are represented in hex (e.g. \x00)

Name: dlg_list_ctx

Parameters: see dlg_list

MI FIFO Command Format:

		opensips-cli -x mi dlg_list_ctx
		

1.9.3. dlg_end_dlg

Terminates an ongoing dialog. If dialog is established, BYEs are sent in both directions. If dialog is in unconfirmed or early state, a CANCEL will be sent to the callee side, that will trigger a 487 from the callee, which, when relayed, will also end the dialog on the caller's side.

Name: dlg_end_dlg

Parameters are:

  • dialog_id - this is an identifier of the dialog - it can be either (1) the unique ID of the dialog (as provided by dlg_list), either (2) the SIP Call-ID of the dialog.

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

The "dialog_id" value can be get via the "dlg_list" MI command.

MI FIFO Command Format:

		# terminate the dialog via the internal Dialog-ID
		opensips-cli -x mi dlg_end_dlg 6ae.4b38d013
		# terminate the dialog via its SIP Call-ID
		opensips-cli -x mi dlg_end_dlg Y2IwYjQ2YmE2ZDg5MWVkNDNkZGIwZjAzNGM1ZDY
		

1.9.4. 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 not value is passed, only simply belonging of the dialog to the profile is checked. Note that the profile does not supports values, this will be silently discarded.

Name: profile_get_size

Parameters:

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

  • value (optional)- string value to toughen the check;

MI FIFO Command Format:

		opensips-cli -x mi profile_get_size inboundCalls
		

1.9.5. profile_list_dlgs

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 - list only the dialogs that were inserted into the profile with that specific value. If not value is passed, all dialogs belonging to the profile will be listed. Note that the profile does not supports values, this will be silently discarded. Also, when using shared profiles using the CacheDB interface, this command will only display the local dialogs.

Name: profile_list_dlgs

Parameters:

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

  • value (optional)- string value to toughen the check;

MI FIFO Command Format:

		opensips-cli -x mi profile_list_dlgs inboundCalls
		

1.9.6. profile_get_values

Lists all the values belonging to a profile along with their count. If the profile does not support values a total count will be returned. Note that this function does not work for shared profiles over the CacheDB interface.

Name: profile_get_values

Parameters:

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

MI FIFO Command Format:

		opensips-cli -x mi profile_get_values inboundCalls
		

1.9.7. profile_end_dlgs

Terminate all ongoing dialogs from a specified profile, on a single dialog it performs the same operations as the command dlg_end_dlg

Name: profile_end_dlgs

Parameters:

  • profile - name of the profile that will have its dialogs termianted

  • value - (optional) if the profile supports values terminate only the dialogs with the specified value

MI FIFO Command Format:

		opensips-cli -x mi profile_end_dlgs inboundCalls
		

1.9.8. dlg_db_sync

Will load all the information about the dialogs from the database in the OpenSIPS internal memory. If a dialog is already found in memory and has the same/an older state, it will be updated with the values from DB. Otherwise, the newer in-memory version will not be changed.

Name: dlg_db_sync

It takes no parameters

MI FIFO Command Format:

		opensips-cli -x mi dlg_db_sync
		

1.9.9. dlg_cluster_sync

This command will only take effect if dialog replication is enabled.

Fully synchronize the dialog information in memory from a suitable donor node within the dialog_replication_cluster. Dialogs that already exist in memory which are not reconfirmed through syncing will be discarded. A sharing tag can be specified in order to sync only dialogs marked with that sharing tag.

Name: dlg_cluster_sync

Parameters:

  • sharing_tag - name of the sharing tag that dialogs have to be marked with in order to be synced

MI FIFO Command Format:

		opensips-cli -x mi dlg_cluster_sync vip1
		

1.9.10. dlg_restore_db

Restores the dialog table after a potential desynchronization event. The table is truncated, then populated with CONFIRMED dialogs from memory.

Name: dlg_restore_db

It takes no parameters

MI FIFO Command Format:

		opensips-cli -x mi dlg_restore_db
		

1.9.11. list_all_profiles

Lists all the dialog profiles, along with 1 or 0 if the given profile has/does not have an associated value.

Name: list_all_profiles

Parameters: It takes no parameters

MI FIFO Command Format:

		opensips-cli -x mi list_all_profiles
		

1.9.12. dlg_push_var

Push or update a dialog value for the given list of dialog IDs / Call-IDs.

Name: dlg_push_var

Parameters: It takes 3 or more parameters

  • dlg_val_name - name of the dialog value that needs to be inserted/updated

  • dlg_val_value - value to be inserted/updated

  • DID - dialog identifier. Can be either the $DLG_did or the actual Call-ID.

MI FIFO Command Format:

		opensips-cli -x mi dlg_push_var var_name var_value DID1 [ DID2 DID3 ...  DIDN ]
		

1.9.13. dlg_send_sequential

Sends a sequential request within an ongoing dialog.

Name: dlg_send_sequential

Parameters:

  • callid - the callid of the dialog you need to trigger the sequential message for.

  • method - (optional) the method used for the sequential message. Default value is INVITE.

  • mode - (optional) can be used to tune the behavior of the sequential message. Possible values for the mode are:

    • caller - (default) sends the sequential message to the caller. This mode can be useful in high availability scenarios when you want to update the upstream's routing set, specifically the contact.

    • callee - same as caller, but sends the sequential message to the callee.

    • challenge - sends a sequential INVITE (or UPDATE) to the caller to challenge it for its advertised SDP body. When the body is received, it is forwarded to the callee. This mode is useful when trying to change both endpoints (upstream and downstream) routing set. It can also be useful when trying to trigger a re-negotiation for SDP body.

    • challenge-caller - same as challenge

    • challenge-callee - same as challenge-caller, only that it first challenges the callee, instead of the caller.

  • body - (optional) can be used to specify a body for the initial sequential message. Possible values for the body parameter are:

    • none - (default) no body added to the sequential message.

    • inbound - advertises in the body of the sequential message generated the last body received from its pair. For example, if the mode=challenge-caller, the message will contain the body sent to OpenSIPS by the callee. This is useful when you need to alter the body previously sent to the caller, because you want to re-negotiate a different media proxy for the call. This can be achieved by catching the generated request in local_route, and re-engage the Media proxy.

    • outbound - advertises in the body of the sequential message generated the last body sent to that UAC. For example, if the mode=challenge-caller, the message will contain the last body sent by OpenSIPS to the caller. This is useful in a high availability scenario when trying to re-negotiate the contact of the server, but there is no need to alter the body sent earlier.

    • custom:CONTENT_TYPE:BODY - this can be used to specify a specific Content-Type ehader and body for the sequential message generated.

This functions runs asynchronously and returns the status code and reason of the last reply received for either the challenge or normal mode.

MI Command Format:

			opensips-cli -x mi dlg_send_sequential \
				callid=5291231-testing@127.0.0.1
		

MI Command used to trigger media re-negotiation:

			opensips-cli -x mi dlg_send_sequential \
				callid=5291231-testing@127.0.0.1 \
				mode=challenge \
				body=inbound
		

MI Command used to UPDATE the callee's remote Contact after a server failover:

			opensips-cli -x mi dlg_send_sequential \
				callid=5291231-testing@127.0.0.1 \
				mode=challenge-callee \
				body=outbound \
				method=UPDATE
		

1.10. Exported Pseudo-Variables

1.10.1. $DLG_count

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

1.10.2. $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.

  • 1 - Dialog unconfirmed (created but no reply received at all)

  • 2 - Dialog in early state (created provisional reply received, but no final reply received yet)

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

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

  • 5 - Dialog ended.

1.10.3. $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.

1.10.4. $DLG_flags

Returns the dialog flags array (as a single integer value) of the dialog corresponding to the processed sequential request. 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.

1.10.5. $DLG_dir

Returns the direction of the request in dialog (as "upstream" string if the request is generated by callee or "downstream" string if the request is generated by caller) - to be used for sequential request. This PV will be available only for sequential requests (not for replies), after doing loose_route().

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

1.10.6. $DLG_did

Returns the id of the dialog corresponding to the processed sequential request. The output format is a string identical to the one returned by the dlg_list MI function. 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.

1.10.7. $DLG_end_reason

Returns the reason for the dialog termination. It can be one of the following :

  • Upstream BYE - Callee has sent a BYE

  • Downstream BYE - Caller has sent a BYE

  • Lifetime Timeout - Dialog lifetime expired

  • MI Termination - Dialog ended via the MI interface

  • Ping Timeout - Dialog ended because no reply to option pings

  • ReINVITE Ping Timeout - Dialog ended because no reply to reinvite pings

  • RTPProxy Timeout - Media timeout signaled by RTPProxy

  • SIP Race Condition - SIP Race Condition occurred

NULL will be returned if there is no dialog for the request, or if the dialog is not ended in the current context.

1.10.8. $DLG_timeout

Used to set the dialog lifetime (in seconds). When read, the variable returns the number of seconds until the dialog expires and is destroyed. Note that reading the variable is only possible after the dialog is created (for initial requests) or after doing loose_route() (for sequential requests). Important notice: using this variable with a REALTIME db_mode is very inefficient, because every time the dialog value is changed, a database update is done.

NULL will be returned if there is no dialog for the request, otherwise the number of seconds until the dialog expiration.

1.10.9. $DLG_json

The variable is read-only and exposes a JSON variable containing all the information that the dlg_list MI function contains

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

1.10.10. $DLG_ctx_json

The variable is read-only and exposes a JSON variable containing all the information that the dlg_list_ctx MI function contains ( on top of $DLG_json, this will expose the full list of dialog vars and profile links for the current dialog )

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

1.10.11. $dlg_val(name)

This is a read/write variable that allows access to the dialog attribute named name. 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.

1.11. Exported Events

1.11.1.  E_DLG_STATE_CHANGED

This event is raised when the dialog state is changed.

Parameters:

  • id - the hex representation of the dialog id.

  • db_id - the integer representation of the dialog id, as it is stored in the database dlg_id field.

  • callid - the callid.

  • from_tag - the From tag.

  • to_tag - the To tag.

  • old_state - the old state of the dialog.

  • new_state - the new state of the dialog.

Chapter 2. Developer Guide

2.1. Available Functions

2.1.1.  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 DLG_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 DLG_CREATED must be register alone. Possible types:

    • DLGCB_LOADED - called when a dialog is loaded from the database, or received by a node using the cluster replication.

    • DLGCB_SAVED

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

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

    • DLG_CONFIRMED - called when the dialog is confirmed (2xx replied) - it's a per dialog type.

    • DLG_REQ_WITHIN - called when the dialog matches a sequential request - it's a per dialog type.

    • DLG_TERMINATED - called when the dialog is terminated via BYE, or by the mi dlg_end_dlg command - it's a per dialog type.

    • DLG_EXPIRED - called when the dialog expires without receiving a BYE - it's a per dialog type. Note that when using replication sharing tags, this callback is only executed by the node that has the Active tag.

    • 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_MI_CONTEXT - called when the mi dlg_list_ctx command is invoked - 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);

Chapter 3. Frequently Asked Questions

3.1.

What happened with topology_hiding() function?

The respective functionality was moved into the topology_hiding module. Function prototype has remained the same.

3.2.

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).

3.3.

What happened with bye_on_timeout_flag parameter?

The parameter was removed in a dialog module parameter restructuring. To keep the bye on timeout behavior, you need to provide a "B" string parameter to the create_dialog() function.

3.4.

What happened with dlg_flag parameter?

The parameter is considered obsolete. The only way to create a dialog is to call the create_dialog() function

3.5.

Where can I find more about OpenSIPS?

Take a look at https://opensips.org/.

3.6.

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 OpenSIPS release should be sent to and e-mails regarding development versions should be sent to .

If you want to keep the mail private, send it to .

3.7.

How can I report a bug?

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

Chapter 4. Contributors

4.1. By Commit Statistics

Table 4.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)

 NameDevScoreCommitsLines ++Lines --
1. Bogdan-Andrei Iancu (@bogdan-iancu)443282128533426
2. Razvan Crainea (@razvancrainea)27420650861560
3. Vlad Paiu (@vladpaiu)25414572063027
4. Vlad Patrascu (@rvlad-patrascu)1859938313269
5. Liviu Chircu (@liviuchircu)16812328951243
6. Ovidiu Sas (@ovidiusas)3526638158
7. Dan Pascu (@danpascu)3025233179
8. Eseanu Marius Cristian (@eseanucristian)186722341
9. Daniel-Constantin Mierla (@miconda)16137666
10. Henning Westerholt (@henningw)1610172187

All remaining contributors: Anca Vamanu, Walter Doekes (@wdoekes), Ionut Ionita (@ionutrazvanionita), Ionel Cerghit (@ionel-cerghit), Andrei Dragus, Maksym Sobolyev (@sobomax), John Riordan, Hugues Mitonneau, Carsten Bock, Jerome Martin, Klaus Darilion, Jarrod Baumann (@jarrodb), Nick Altmann (@nikbyte), Zero King (@l2dy), Michel Bensoussan, Richard Revels, Elena-Ramona Modroiu, Tavis Paquette, Andrei Datcu (@andrei-datcu), Jeffrey Magder, Ron Winacott, Andy Pyles, Julián Moreno Patiño, Konstantin Bokarius, sergei lavrov, Alex Massover, Damien Sandras (@dsandras), Alex Hermann, Dusan Klinec (@ph4r05), Norman Brandinger (@NormB), Peter Lemenkov (@lemenkov), UnixDev, Eliot Gable, Ryan Bullock (@rrb3942), Edson Gellert Schubert.

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

4.2. By Commit Activity

Table 4.2. Most recently active contributors(1) to this module

 NameCommit Activity
1. Bogdan-Andrei Iancu (@bogdan-iancu)Apr 2006 - Dec 2023
2. Liviu Chircu (@liviuchircu)Aug 2012 - Nov 2023
3. Vlad Paiu (@vladpaiu)Oct 2010 - Nov 2023
4. Razvan Crainea (@razvancrainea)Aug 2010 - Oct 2023
5. Ovidiu Sas (@ovidiusas)Feb 2008 - Jun 2023
6. Vlad Patrascu (@rvlad-patrascu)Jul 2016 - Jul 2022
7. Nick Altmann (@nikbyte)Oct 2013 - May 2021
8. Walter Doekes (@wdoekes)Apr 2010 - Apr 2021
9. Maksym Sobolyev (@sobomax)Nov 2020 - Jan 2021
10. sergei lavrovDec 2020 - Dec 2020

All remaining contributors: Zero King (@l2dy), Dan Pascu (@danpascu), Peter Lemenkov (@lemenkov), Ionel Cerghit (@ionel-cerghit), Jarrod Baumann (@jarrodb), Ionut Ionita (@ionutrazvanionita), Julián Moreno Patiño, Dusan Klinec (@ph4r05), Eseanu Marius Cristian (@eseanucristian), Andrei Datcu (@andrei-datcu), Norman Brandinger (@NormB), Damien Sandras (@dsandras), Ryan Bullock (@rrb3942), Anca Vamanu, Alex Massover, Andrei Dragus, John Riordan, Hugues Mitonneau, Richard Revels, UnixDev, Alex Hermann, Henning Westerholt (@henningw), Carsten Bock, Klaus Darilion, Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Jerome Martin, Tavis Paquette, Michel Bensoussan, Eliot Gable, Andy Pyles, Elena-Ramona Modroiu, Jeffrey Magder, Ron Winacott.

(1) including any documentation-related commits, excluding merge commits

Chapter 5. Documentation

5.1. Contributors

Last edited by: Bogdan-Andrei Iancu (@bogdan-iancu), Liviu Chircu (@liviuchircu), Vlad Patrascu (@rvlad-patrascu), Razvan Crainea (@razvancrainea), Vlad Paiu (@vladpaiu), Zero King (@l2dy), Dan Pascu (@danpascu), Peter Lemenkov (@lemenkov), Julián Moreno Patiño, Ionut Ionita (@ionutrazvanionita), Ionel Cerghit (@ionel-cerghit), Walter Doekes (@wdoekes), Eseanu Marius Cristian (@eseanucristian), Norman Brandinger (@NormB), Anca Vamanu, Andrei Dragus, Hugues Mitonneau, Klaus Darilion, Henning Westerholt (@henningw), Ovidiu Sas (@ovidiusas), Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Michel Bensoussan, Andy Pyles, Elena-Ramona Modroiu.

Documentation Copyrights:

Copyright © 2006-2009 Voice Sistem SRL