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)

        1.7. 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. set_dlg_profile(profile,[value])
              1.7.10. unset_dlg_profile(profile,[value])
              1.7.11. is_in_profile(profile,[value])
              1.7.12. get_profile_size(profile,[value],size)
              1.7.13. set_dlg_flag(idx)
              1.7.14. test_and_set_dlg_flag(idx, value)
              1.7.15. reset_dlg_flag(idx)
              1.7.16. is_dlg_flag_set(idx)
              1.7.17. store_dlg_value(name,val)
              1.7.18. fetch_dlg_value(name,val)
              1.7.19. set_dlg_sharing_tag(tag_name)

        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. create_dialog() usage
   1.53. match_dialog() usage
   1.54. validate_dialog() usage
   1.55. fix_route_dialog() usage
   1.56. get_dialog_info usage
   1.57. get_dialog_vals usage
   1.58. get_dialog_vals usage
   1.59. get_dialog_vals usage
   1.60. set_dlg_profile usage
   1.61. unset_dlg_profile usage
   1.62. is_in_profile usage
   1.63. get_profile_size usage
   1.64. set_dlg_flag usage
   1.65. test_and_set_dlg_flag usage
   1.66. reset_dlg_flag usage
   1.67. is_dlg_flag_set usage
   1.68. store_dlg_value usage
   1.69. fetch_dlg_value usage
   1.70. set_dlg_sharing_tag usage

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. In consequence dialogs loaded from the
   database at startup are dropped and also deleted from the DB
   once the sync from cluster is complete. This is done for
   dialogs that are not reconfirmed as being active in the
   meantime (SIP updates, received in sync data).

   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 “hash_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 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", "caller ; my_profile; share/s;
 repl/b;")
...

1.6.37. profiles_no_value (string)

   List of names 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 200OK with
   CANCEL race condition occurs, then the dialog will be
   terminated after 'race_condition_timeout' seconds.

   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 10 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)
...

1.7. 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
   whether the dialog end-points should be pinged via SIP options
   messages. The parameter can be "P" to specify to only ping the
   caller, "p" to only ping the callee or "Pp" to ping both dialog
   sides. If the extra string parameter is provided and one
   end-point fails to respond to a options ping, OpenSIPS will
   terminate the dialog from the middle. Also, the end-points can
   be pinged via in-dialog Re-INVITE SIP messages. This behaviour
   is controlled via the "R" flags for pinging the caller side,
   and the "r" flag for re-invite pinging the callee side. If one
   end-points fails to re-negociate the session via the Re-INVITE
   pings, OpenSIPS will terminate the dialog from the middle The
   string parameter can also contain "B" to activate the bye on
   timeout behavior.

   Parameters:
     * flags (string, optional)

   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 1.52. 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 1.53. 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 1.54. 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 1.55. 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 1.56. get_dialog_info usage
...
if ( get_dialog_info("callee",$avp(callee_array),"caller",$fu,$var(dlg_n
o)) ) {
        xlog("caller $fu has $var(dlg_no) other ongoing calls, talking w
ith :");
        $var(it) = 0;
        while ($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 attribu
tes
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 1.57. 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)])='$(avp(d_v
als)[$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 1.58. 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 1.59. 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.  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 1.60. set_dlg_profile usage
...
set_dlg_profile("inbound_call");
set_dlg_profile("caller",$fu);
...

1.7.10.  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 1.61. unset_dlg_profile usage
...
unset_dlg_profile("inbound_call");
unset_dlg_profile("caller",$fu);
...

1.7.11.  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 1.62. 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");
}
...

1.7.12.  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 1.63. 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");
...

1.7.13.  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 1.64. set_dlg_flag usage
...
set_dlg_flag(3);
...

1.7.14.  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 1.65. test_and_set_dlg_flag usage
...
test_and_set_dlg_flag(3, 0);
...

1.7.15.  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 1.66. reset_dlg_flag usage
...
reset_dlg_flag(16);
...

1.7.16.  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 1.67. is_dlg_flag_set usage
...
if (is_dlg_flag_set(16)) {
        xlog("dialog flag 16 is set\n");
}
...

1.7.17.  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 1.68. store_dlg_value usage
...
store_dlg_value("inv_src_ip",$si);
store_dlg_value("account type","prepaid");
# or
$dlg_val(account_type) = "prepaid";
...

1.7.18.  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 1.69. 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);
...

1.7.19.  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 1.70. set_dlg_sharing_tag usage
...
set_dlg_sharing_tag("vip1");
...

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 abcdrssfrs122444@192.168.1.1
 AAdfeEFF33
                ## list 10 dialogs, starting from the position 40
                ## (in the list of all ongoing dialogs)
                opensips-cli -x mi dlg_list 40 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 numerical 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 1391569858236
                # terminate the dialog via its SIP Call-ID
                opensips-cli -x mi dlg_end_dlg Y2IwYjQ2YmE2ZDg5MWVkNDNkZ
GIwZjAzNGM1ZDY

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 inbound_calls

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 inbound_calls

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 inbound_calls

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 inbound_calls

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.

   The current node will locate a suitable donor node within the
   dialog_replication_cluster and issue a sync request to it. The
   donor node will then push all the dialog information to the
   current node, via the the binary interface. For dialogs that
   already exist in memory, the information will be not be treated
   as an update but discarded instead.

   Name: dlg_cluster_sync

   It takes no parameters

   MI FIFO Command Format:
                opensips-cli -x mi dlg_cluster_sync

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
       sequentiam message for.
     * method - (optional) the method used for the sequential
       mesasge. 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-caller - 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-negociate 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-negociate 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 in asynchronous mode 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"
   or "DOWNSTREAM" string) - to be used for sequential request.
   This PV will be available only for sequential requests (on
   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 entry ':' id (as
   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 in-dialog
       pings
     * RTPProxy Timeout - Media timeout signaled by RTPProxy

   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:
     * hash_entry - the entry in the dialog table. This is used,
       along with the hash_id, to uniquely identify the dialog.
     * hash_id - the id in the dialog table. This is used, along
       with the hash_entry, to uniquely identify the dialog.
     * 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 http://www.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:
         * User Mailing List -
           http://lists.opensips.org/cgi-bin/mailman/listinfo/users
         * Developer Mailing List -
           http://lists.opensips.org/cgi-bin/mailman/listinfo/devel

       E-mails regarding any stable OpenSIPS release should be sent to
       <users@lists.opensips.org> and e-mails regarding development
       versions should be sent to <devel@lists.opensips.org>.

       If you want to keep the mail private, send it to
       <users@lists.opensips.org>.

   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)
     Name DevScore Commits Lines ++ Lines --
   1. Bogdan-Andrei Iancu (@bogdan-iancu) 412 261 12066 3113
   2. Vlad Paiu (@vladpaiu) 250 140 7051 3004
   3. Razvan Crainea (@razvancrainea) 173 125 3774 1004
   4. Vlad Patrascu (@rvlad-patrascu) 149 68 3286 3061
   5. Liviu Chircu (@liviuchircu) 105 73 2252 739
   6. Ovidiu Sas (@ovidiusas) 27 21 482 107
   7. Dan Pascu (@danpascu) 26 22 160 106
   8. Eseanu Marius Cristian (@eseanucristian) 19 6 722 341
   9. Daniel-Constantin Mierla (@miconda) 16 13 76 66
   10. Henning Westerholt (@henningw) 16 10 172 187

   All remaining contributors: Anca Vamanu, Ionut Ionita
   (@ionutrazvanionita), Andrei Dragus, Ionel Cerghit
   (@ionel-cerghit), Walter Doekes (@wdoekes), John Riordan,
   Hugues Mitonneau, Carsten Bock, Jerome Martin, Klaus Darilion,
   Jarrod Baumann (@jarrodb), Michel Bensoussan, Richard Revels,
   Elena-Ramona Modroiu, Tavis Paquette, Andrei Datcu
   (@andrei-datcu), Jeffrey Magder, Ron Winacott, Andy Pyles,
   Julián Moreno Patiño, Konstantin Bokarius, Alex Massover,
   Damien Sandras (@dsandras), Alex Hermann, Dusan Klinec, Norman
   Brandinger (@NormB), Peter Lemenkov (@lemenkov), UnixDev, Eliot
   Gable, Ryan Bullock (@rrb3942), Nick Altmann (@nikbyte), 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
                      Name                   Commit Activity
   1.  Bogdan-Andrei Iancu (@bogdan-iancu) Apr 2006 - May 2019
   2.  Liviu Chircu (@liviuchircu)         Aug 2012 - May 2019
   3.  Vlad Patrascu (@rvlad-patrascu)     Jul 2016 - May 2019
   4.  Razvan Crainea (@razvancrainea)     Aug 2010 - May 2019
   5.  Vlad Paiu (@vladpaiu)               Oct 2010 - Sep 2018
   6.  Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   7.  Ovidiu Sas (@ovidiusas)             Feb 2008 - Mar 2017
   8.  Ionel Cerghit (@ionel-cerghit)      Jul 2015 - Dec 2016
   9.  Jarrod Baumann (@jarrodb)           Apr 2015 - Apr 2016
   10. Ionut Ionita (@ionutrazvanionita)   Oct 2014 - Feb 2016

   All remaining contributors: Julián Moreno Patiño, Dusan Klinec,
   Walter Doekes (@wdoekes), Eseanu Marius Cristian
   (@eseanucristian), Andrei Datcu (@andrei-datcu), Nick Altmann
   (@nikbyte), Norman Brandinger (@NormB), Damien Sandras
   (@dsandras), Ryan Bullock (@rrb3942), Anca Vamanu, Alex
   Massover, Andrei Dragus, John Riordan, Hugues Mitonneau,
   Richard Revels, UnixDev, Dan Pascu (@danpascu), 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: Razvan Crainea (@razvancrainea), Vlad Patrascu
   (@rvlad-patrascu), Bogdan-Andrei Iancu (@bogdan-iancu), Vlad
   Paiu (@vladpaiu), Liviu Chircu (@liviuchircu), 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, Dan Pascu
   (@danpascu), Michel Bensoussan, Andy Pyles, Elena-Ramona
   Modroiu.

   Documentation Copyrights:

   Copyright © 2006-2009 Voice Sistem SRL
