USRLOC module
Admin Guide
Section titled “Admin Guide”Overview
Section titled “Overview”User location module. The module keeps a user location table and provides access to the table to other modules. The module exports no functions that could be used directly from scripts.
Contact matching
Section titled “Contact matching”How the contacts are matched (dor same AOR - Address of Record) is an important aspect of the usrloc modules, especialy in the context of NAT traversal - this raise mre problems since contacts from different phones of same users may overlap (if behind NATs with same configuration) or the re-register contact of same phone may be seen as a new one (due different binding via NAT).
The SIP RFC 3261 publishes a matching algorithm based only on the contact string with callid and cseq number extra checking (if callid is the same, it must have a higher cseq number, otherwise invalid). But as argumented above, this is not enough in NAT traversal context, so the OpenSIPS implementation of contact machting offers more algorithms:
- contact based only - it strict RFC 3261 compiancy - the contact is matched as string and extra checked via callid and cseg (if callid is the same, it must have a higher cseq number, otherwise invalid).
- contact nad callid based - it an extension of the first case - the contact and callid must matched as string; the cseg must be higher than the previous one - so be careful how you deal with REGISTER retransmissions in this case.
How to control/select the contact maching algorithm, please see the module parameter matching_mode at matching mode.
Dependencies
Section titled “Dependencies”OpenSIPS Modules
Section titled “OpenSIPS Modules”The following modules must be loaded before this module:
- Optionally a database module.
External Libraries or Applications
Section titled “External Libraries or Applications”The following libraries or applications must be installed before running OpenSIPS with this module loaded:
- None.
Exported Parameters
Section titled “Exported Parameters”nat_bflag (integer)
Section titled “nat_bflag (integer)”The index of the branch flag to be used as NAT marker (if the contact is or not natted). This is a branch flag and it will be imported and used by all other modules depending of usrloc module.
Default value is “not set”.
...modparam("usrloc", "nat_bflag", 3)...user_column (string)
Section titled “user_column (string)”Name of column containing usernames.
Default value is “username”.
...modparam("usrloc", "user_column", "username")...domain_column (string)
Section titled “domain_column (string)”Name of column containing domains.
Default value is “domain”.
...modparam("usrloc", "domain_column", "domain")...contact_column (string)
Section titled “contact_column (string)”Name of column containing contacts.
Default value is “contact”.
...modparam("usrloc", "contact_column", "contact")...expires_column (string)
Section titled “expires_column (string)”Name of column containing expires value.
Default value is “expires”.
...modparam("usrloc", "expires_column", "expires")...q_column (string)
Section titled “q_column (string)”Name of column containing q values.
Default value is “q”.
...modparam("usrloc", "q_column", "q")...callid_column (string)
Section titled “callid_column (string)”Name of column containing callid values.
Default value is “callid”.
...modparam("usrloc", "callid_column", "callid")...cseq_column (string)
Section titled “cseq_column (string)”Name of column containing cseq numbers.
Default value is “cseq”.
...modparam("usrloc", "cseq_column", "cseq")...methods_column (string)
Section titled “methods_column (string)”Name of column containing supported methods.
Default value is “methods”.
...modparam("usrloc", "methods_column", "methods")...flags_column (string)
Section titled “flags_column (string)”Name of column to save the internal flags of the record.
Default value is “flags”.
...modparam("usrloc", "flags_column", "flags")...cflags_column (string)
Section titled “cflags_column (string)”Name of column to save the branch/contact flags of the record.
Default value is “cflags”.
...modparam("usrloc", "cflags_column", "cflags")...user_agent_column (string)
Section titled “user_agent_column (string)”Name of column containing user-agent values.
Default value is “user_agent”.
...modparam("usrloc", "user_agent_column", "user_agent")...received_column (string)
Section titled “received_column (string)”Name of column containing the source IP, port, and protocol from the REGISTER message.
Default value is “received”.
...modparam("usrloc", "received_column", "received")...socket_column (string)
Section titled “socket_column (string)”Name of column containing the received socket information (IP:port) for the REGISTER message.
Default value is “socket”.
...modparam("usrloc", "socket_column", "socket")...path_column (string)
Section titled “path_column (string)”Name of column containing the Path header.
Default value is “path”.
...modparam("usrloc", "path_column", "path")...use_domain (integer)
Section titled “use_domain (integer)”If the domain part of the user should be also saved and used for identifing the user (along with the username part). Useful in multi domain scenarios. Non 0 value means true.
Default value is “0 (false)“.
...modparam("usrloc", "use_domain", 1)...desc_time_order (integer)
Section titled “desc_time_order (integer)”If the user’s contacts should be kept timestamp ordered; otherwise the contact will be ordered based on q value. Non 0 value means true.
Default value is “0 (false)“.
...modparam("usrloc", "desc_time_order", 1)...timer_interval (integer)
Section titled “timer_interval (integer)”Number of seconds between two timer runs. The module uses timer to delete expired contacts, synchronize with database and other tasks, that need to be run periodically.
Default value is 60.
...modparam("usrloc", "timer_interval", 120)...db_url (string)
Section titled “db_url (string)”URL of the database that should be used.
Default value is “mysql://opensips:opensipsrw@localhost/opensips”.
...modparam("usrloc", "db_url", "dbdriver://username:password@dbhost/dbname")...db_mode (integer)
Section titled “db_mode (integer)”The usrloc module can utilize database for persistent contact storage. If you use database, your contacts will survive machine restarts or SW crashes. The disadvantage is that accessing database can be very time consuming. Therefore, usrloc module implements four database accessing modes:
- 0 - This disables database completely. Only memory will be used. Contacts will not survive restart. Use this value if you need a really fast usrloc and contact persistence is not necessary or is provided by other means.
- 1 - Write-Through scheme. All changes to usrloc are immediately reflected in database too. This is very slow, but very reliable. Use this scheme if speed is not your priority but need to make sure that no registered contacts will be lost during crash or reboot.
- 2 - Write-Back scheme. This is a combination of previous two schemes. All changes are made to memory and database synchronization is done in the timer. The timer deletes all expired contacts and flushes all modified or new contacts to database. Use this scheme if you encounter high-load peaks and want them to process as fast as possible. The mode will not help at all if the load is high all the time. Also, latency of this mode is much lower than latency of mode 1, but slightly higher than latency of mode 0.
- 3 - DB-Only scheme. No memory cache is kept, all operations being directly performed with the database. The timer deletes all expired contacts from database - cleans after clients that didn’t un-register or re-register. The mode is useful if you configure more servers sharing the same DB without any replication at SIP level. The mode may be slower due the high number of DB operation. For example NAT pinging is a killer since during each ping cycle all nated contact are loaded from the DB; The lack of memory caching also disable the statistics exports.
Default value is 0.
...modparam("usrloc", "db_mode", 2)...matching_mode (integer)
Section titled “matching_mode (integer)”What contact matching algorithm to be used. Refer to section contact matching algs for the description of the algorithms.
The parameter may take the following values:
- 0 - CONTACT ONLY based matching algorithm.
- 1 - CONTACT and CALLID based matching algorithm.
Default value is 0 (CONTACT_ONLY).
...modparam("usrloc", "matching_mode", 1)...cseq_delay (integer)
Section titled “cseq_delay (integer)”Delay (in seconds) for accepting as retransmissions register requests with same Call-ID and Cseq. The delay is calculated starting from the receiving time of the first register with that Call-ID and Cseq.
Retransmissions within this delay interval will be accepted and replied as the original request, but no update will be done in location. If the delay is exceeded, error is reported.
A value of 0 disable the retransmission detection.
Default value is “20 seconds”.
...modparam("usrloc", "cseq_delay", 5)...hash_size (integer)
Section titled “hash_size (integer)”The number of entries of the hash table used by usrloc to store the location records is 2^hash_size. For hash_size=4, the number of entries of the hash table is 16.
Default value is “9”.
...modparam("usrloc", "hash_size", 10)...Exported Functions
Section titled “Exported Functions”There are no exported functions that could be used in scripts.
Exported MI Functions
Section titled “Exported MI Functions”Deletes an entire AOR record (including its contacts).
Parameters:
- table name - table where the AOR is removed from (Ex: location).
- AOR - user AOR in username[@domain] format (domain must be supplied only if use_domain option is on).
ul_rm_contact
Section titled “ul_rm_contact”Deletes a contact from an AOR record.
Parameters:
- table name - table where the AOR is removed from (Ex: location).
- AOR - user AOR in username[@domain] format (domain must be supplied only if use_domain option is on).
- contact - exact contact to be removed
ul_dump
Section titled “ul_dump”Dumps the entire content of the USRLOC in memory cache
Parameters:
- brief - (optional, may not be present); if equals to string “brief”, a brief dump will be done (only AOR and contacts, with no other details)
ul_flush
Section titled “ul_flush”Triggers the flush of USRLOC memory cache into DB.
ul_add
Section titled “ul_add”Adds a new contact for an user AOR.
Parameters:
- table name - table where the contact will be added (Ex: location).
- AOR - user AOR in username[@domain] format (domain must be supplied only if use_domain option is on).
- contact - contact string to be added
- expires - expires value of the contact
- Q - Q value of the contact
- unused - unused attribute (kept for backword compatibility)
- flags - internal USRLOC flags of the contact
- cflags - per branch flags of the contact
- methods - mask with supported requests of the contact
ul_show_contact
Section titled “ul_show_contact”Dumps the contacts of an user AOR.
Parameters:
- table name - table where the AOR resides (Ex: location).
- AOR - user AOR in username[@domain] format (domain must be supplied only if use_domain option is on).
ul_sync
Section titled “ul_sync”Synchronizes the contacts from memory with the ones from database. Note that this can not be used when no database is specified or with the DB-Only scheme.
Important: make sure that all your contacts are in memory (ul_dump MI function) before executing this command. If the AOR is not specified, the whole table will be synchronized.
Parameters:
- table name - table where the AOR resides (Ex: location).
- AOR (optional) - user AOR in username[@domain] format (domain must be supplied only if use_domain option is on).
Exported Statistics
Section titled “Exported Statistics”Exported statistics are listed in the next sections.
Number of AOR existing in the USRLOC memory cache for that domain - can not be resetted; this statistic will be register for each used domain (Ex: location).
contacts
Section titled “contacts”Number of contacts existing in the USRLOC memory cache for that domain - can not be resetted; this statistic will be register for each used domain (Ex: location).
expires
Section titled “expires”Total number of expired contacts for that domain - can be resetted; this statistic will be register for each used domain (Ex: location).
registered_users
Section titled “registered_users”Total number of AOR existing in the USRLOC memory cache for all domains - can not be resetted.
Developer Guide
Section titled “Developer Guide”Available Functions
Section titled “Available Functions”ul_register_domain(name)
Section titled “ul_register_domain(name)”The function registers a new domain. Domain is just another name for table used in registrar. The function is called from fixups in registrar. It gets name of the domain as a parameter and returns pointer to a new domain structure. The fixup than ‘fixes’ the parameter in registrar so that it will pass the pointer instead of the name every time save() or lookup() is called. Some usrloc functions get the pointer as parameter when called. For more details see implementation of save function in registrar.
Meaning of the parameters is as follows:
- const char name* - Name of the domain (also called table) to be registered.
ul_insert_urecord(domain, aor, rec)
Section titled “ul_insert_urecord(domain, aor, rec)”The function creates a new record structure and inserts it in the specified domain. The record is structure that contains all the contacts for belonging to the specified username.
Meaning of the parameters is as follows:
-
udomain_t domain* - Pointer to domain returned by ul_register_udomain.
-
str aor* - Address of Record (aka username) of the new record (at this time the record will contain no contacts yet).
-
urecord_t* rec* - The newly created record structure.
ul_delete_urecord(domain, aor)
Section titled “ul_delete_urecord(domain, aor)”The function deletes all the contacts bound with the given Address Of Record.
Meaning of the parameters is as follows:
-
udomain_t domain* - Pointer to domain returned by ul_register_udomain.
-
str aor* - Address of record (aka username) of the record, that should be deleted.
ul_get_urecord(domain, aor)
Section titled “ul_get_urecord(domain, aor)”The function returns pointer to record with given Address of Record.
Meaning of the parameters is as follows:
-
udomain_t domain* - Pointer to domain returned by ul_register_udomain.
-
str aor* - Address of Record of request record.
ul_lock_udomain(domain)
Section titled “ul_lock_udomain(domain)”The function lock the specified domain, it means, that no other processes will be able to access during the time. This prevents race conditions. Scope of the lock is the specified domain, that means, that multiple domain can be accessed simultaneously, they don’t block each other.
Meaning of the parameters is as follows:
- udomain_t domain* - Domain to be locked.
ul_unlock_udomain(domain)
Section titled “ul_unlock_udomain(domain)”Unlock the specified domain previously locked by ul_lock_udomain.
Meaning of the parameters is as follows:
- udomain_t domain* - Domain to be unlocked.
ul_release_urecord(record)
Section titled “ul_release_urecord(record)”Do some sanity checks - if all contacts have been removed, delete the entire record structure.
Meaning of the parameters is as follows:
- urecord_t record* - Record to be released.
ul_insert_ucontact(record, contact, expires, q, callid, cseq, flags, cont, ua, sock)
Section titled “ul_insert_ucontact(record, contact, expires, q, callid, cseq, flags, cont, ua, sock)”The function inserts a new contact in the given record with specified parameters.
Meaning of the parameters is as follows:
- urecord_t record* - Record in which the contact should be inserted.
- str contact* - Contact URI.
- time_t expires - Expires of the contact in absolute value.
- float q - q value of the contact.
- str callid* - Call-ID of the REGISTER message that contained the contact.
- int cseq - CSeq of the REGISTER message that contained the contact.
- unsigned int flags - Flags to be set.
- ucontact_t cont* - Pointer to newly created structure.
- str ua* - User-Agent of the REGISTER message that contained the contact.
- *struct socket_info sock - socket on which the REGISTER message was received on.
ul_delete_ucontact (record, contact)
Section titled “ul_delete_ucontact (record, contact)”The function deletes given contact from record.
Meaning of the parameters is as follows:
-
urecord_t record* - Record from which the contact should be removed.
-
ucontact_t contact* - Contact to be deleted.
ul_get_ucontact(record, contact)
Section titled “ul_get_ucontact(record, contact)”The function tries to find contact with given Contact URI and returns pointer to structure representing the contact.
Meaning of the parameters is as follows:
-
urecord_t record* - Record to be searched for the contact.
-
str_t contact* - URI of the request contact.
ul_get_all_ucontacts (buf, len, flags)
Section titled “ul_get_all_ucontacts (buf, len, flags)”The function retrieves all contacts of all registered users and returns them in the caller-supplied buffer. If the buffer is too small, the function returns positive value indicating how much additional space would be necessary to accommodate all of them. Please note that the positive return value should be used only as a “hint”, as there is no guarantee that during the time between two subsequent calls number of registered contacts will remain the same.
If flag parameter is set to non-zero value then only contacts that have the specified flags set will be returned. It is, for example, possible to list only contacts that are behind NAT.
Meaning of the parameters is as follows:
-
void buf* - Buffer for returning contacts.
-
int len - Length of the buffer.
-
unsigned int flags - Flags that must be set.
ul_update_ucontact(contact, expires, q, callid, cseq, set, res, ua, sock)
Section titled “ul_update_ucontact(contact, expires, q, callid, cseq, set, res, ua, sock)”The function updates contact with new values.
Meaning of the parameters is as follows:
- ucontact_t contact* - Contact URI.
- time_t expires - Expires of the contact in absolute value.
- float q - q value of the contact.
- str callid* - Call-ID of the REGISTER message that contained the contact.
- int cseq - CSeq of the REGISTER message that contained the contact.
- unsigned int set - OR value of flags to be set.
- unsigned int res - OR value of flags to be reset.
- str ua* - User-Agent of the REGISTER message that contained the contact.
- *struct socket_info sock - socket on which the REGISTER message was received on.
ul_bind_ursloc( api )
Section titled “ul_bind_ursloc( api )”The function imports all functions that are exported by the USRLOC module. Overs for other modules which want to user the internal USRLOC API an easy way to load and access the functions.
Meaning of the parameters is as follows:
- usrloc_api_t api* - USRLOC API
ul_register_ulcb(type ,callback, param)
Section titled “ul_register_ulcb(type ,callback, param)”The function register with USRLOC a callback function to be called when some event occures inside USRLOC.
Meaning of the parameters is as follows:
- int types - type of event for which the callback should be called (see usrloc/ul_callback.h).
- ul_cb f - callback function; see usrloc/ul_callback.h for prototype.
- *void param - some parameter to be passed to the callback each time when it is called.
ul_get_num_users()
Section titled “ul_get_num_users()”The function loops through all domains summing up the number of users.
Contributors
Section titled “Contributors”By Commit Statistics
Section titled “By Commit Statistics”Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| # | Name | DevScore | Commits | Lines++ | Lines— |
|---|---|---|---|---|---|
| 1. | Jan Janak (@janakj) | 429 | 117 | 16018 | 10675 |
| 2. | Bogdan-Andrei Iancu (@bogdan-iancu) | 203 | 108 | 3984 | 3626 |
| 3. | Daniel-Constantin Mierla (@miconda) | 42 | 29 | 647 | 411 |
| 4. | Jiri Kuthan (@jiriatipteldotorg) | 37 | 25 | 976 | 121 |
| 5. | Henning Westerholt (@henningw) | 21 | 11 | 464 | 358 |
| 6. | Andrei Pelinescu-Onciul | 17 | 13 | 156 | 96 |
| 7. | Stefan Darius (@dariusstefan) | 17 | 3 | 1159 | 188 |
| 8. | Vlad Paiu (@vladpaiu) | 11 | 9 | 111 | 41 |
| 9. | Nils Ohlmeier | 10 | 8 | 39 | 16 |
| 10. | Razvan Crainea (@razvancrainea) | 10 | 7 | 183 | 22 |
All remaining contributors: Maksym Sobolyev (@sobomax), Andrei Dragus, Anca Vamanu, Juha Heinanen (@juha-h), Marcus Hunger, Jamey Hicks, Andreas Granig, Jeffrey Magder, Phil D’Amore, Norman Brandinger (@NormB), Konstantin Bokarius, Klaus Darilion, Iouri Kharon, Ovidiu Sas (@ovidiusas), UnixDev, Matthew M. Boedicker, Edson Gellert Schubert, Elena-Ramona Modroiu.
(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
(3) ignoring whitespace edits, renamed files and auto-generated files
By Commit Activity
Section titled “By Commit Activity”| # | Name | Commit Activity |
|---|---|---|
| 1. | Stefan Darius (@dariusstefan) | Jun 2026 - Jul 2026 |
| 2. | Razvan Crainea (@razvancrainea) | Jul 2011 - Jun 2026 |
| 3. | Bogdan-Andrei Iancu (@bogdan-iancu) | Mar 2002 - Sep 2015 |
| 4. | Vlad Paiu (@vladpaiu) | Jun 2011 - Mar 2013 |
| 5. | Andrei Dragus | Nov 2009 - Apr 2010 |
| 6. | Phil D’Amore | Aug 2009 - Aug 2009 |
| 7. | UnixDev | Feb 2009 - Feb 2009 |
| 8. | Daniel-Constantin Mierla (@miconda) | Jul 2005 - Jul 2008 |
| 9. | Henning Westerholt (@henningw) | May 2007 - Jul 2008 |
| 10. | Iouri Kharon | Apr 2008 - Apr 2008 |
All remaining contributors: Ovidiu Sas (@ovidiusas), Konstantin Bokarius, Edson Gellert Schubert, Anca Vamanu, Matthew M. Boedicker, Marcus Hunger, Elena-Ramona Modroiu, Jeffrey Magder, Norman Brandinger (@NormB), Andreas Granig, Juha Heinanen (@juha-h), Klaus Darilion, Jan Janak (@janakj), Andrei Pelinescu-Onciul, Jiri Kuthan (@jiriatipteldotorg), Maksym Sobolyev (@sobomax), Jamey Hicks, Nils Ohlmeier.
(1) including any documentation-related commits, excluding merge commits
Documentation
Section titled “Documentation”Contributors
Section titled “Contributors”Last edited by: Razvan Crainea (@razvancrainea), Bogdan-Andrei Iancu (@bogdan-iancu), Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Henning Westerholt (@henningw), Marcus Hunger, Elena-Ramona Modroiu, Juha Heinanen (@juha-h), Jan Janak (@janakj), Maksym Sobolyev (@sobomax), Nils Ohlmeier.
License
Section titled “License”All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0