Table of Contents
List of Tables
List of Examples
sl_send_reply usagesl_reply_error usageThe SL module allows OpenSIPS to act as a stateless UA server and generate replies to SIP requests without keeping state. That is beneficial in many scenarios, in which you wish not to burden server's memory and scale well.
The SL module needs to filter ACKs sent after a local stateless reply to an INVITE was generated. To recognize such ACKs, OpenSIPS adds a special "signature" in to-tags. This signature is sought for in incoming ACKs, and if included, the ACKs are absorbed.
To speed up the filtering process, the module uses a timeout mechanism. When a reply is sent, a timer is set. As time as the timeout didn't hit, the incoming ACK requests will be checked using TO tag value. Once the timer expires, all the ACK are let through - a long time passed till it sent a reply, so it does not expect any ACK that have to be blocked.
The ACK filtering may fail in some rare cases. If you think these matter to you, better use stateful processing (tm module) for INVITE processing. Particularly, the problem happens when a UA sends an INVITE which already has a to-tag in it (e.g., a re-INVITE) and OpenSIPS want to reply to it. Than, it will keep the current to-tag, which will be mirrored in ACK. OpenSIPS will not see its signature and forward the ACK downstream. Caused harm is not bad--just a useless ACK is forwarded.
The following modules must be loaded before this module:
No dependencies on other OpenSIPS modules.
If the module should generate and export statistics to the core manager. A zero value means disabled.
SL module provides statistics about how many replies were sent ( splitted per code classes) and how many local ACKs were filtered out.
Default value is 1 (enabled).
For the current request, a reply is sent back having the given code and text reason. The reply is sent stateless, totally independent of the Transaction module and with no retransmission for the INVITE's replies. 'code' and 'reason' can contain pseudo-variables that are replaced at runtime.
Meaning of the parameters is as follows:
code (int) - Return code.
reason (string) - Reason phrase.
This function can be used from REQUEST_ROUTE, ERROR_ROUTE.
Example 1.2. sl_send_reply usage
... sl_send_reply(404, "Not found"); ... sl_send_reply($err.rcode, $err.rreason); ...
Table 2.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| Name | DevScore | Commits | Lines ++ | Lines -- | |
|---|---|---|---|---|---|
| 1. | Bogdan-Andrei Iancu (@bogdan-iancu) | 75 | 55 | 884 | 711 |
| 2. | Jiri Kuthan (@jiriatipteldotorg) | 42 | 32 | 665 | 232 |
| 3. | Daniel-Constantin Mierla (@miconda) | 22 | 16 | 295 | 172 |
| 4. | Andrei Pelinescu-Onciul | 16 | 14 | 50 | 50 |
| 5. | Liviu Chircu (@liviuchircu) | 13 | 10 | 28 | 62 |
| 6. | Jan Janak (@janakj) | 12 | 8 | 355 | 21 |
| 7. | Henning Westerholt (@henningw) | 7 | 5 | 12 | 12 |
| 8. | Razvan Crainea (@razvancrainea) | 7 | 5 | 12 | 11 |
| 9. | Vlad Patrascu (@rvlad-patrascu) | 7 | 4 | 30 | 83 |
| 10. | Maksym Sobolyev (@sobomax) | 5 | 3 | 8 | 9 |
All remaining contributors: Elena-Ramona Modroiu, Jeffrey Magder, Andreas Heise, Konstantin Bokarius, Anca Vamanu, Ionut Ionita (@ionutrazvanionita), Peter Lemenkov (@lemenkov), 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
Table 2.2. Most recently active contributors(1) to this module
| Name | Commit Activity | |
|---|---|---|
| 1. | Liviu Chircu (@liviuchircu) | Mar 2014 - May 2024 |
| 2. | Bogdan-Andrei Iancu (@bogdan-iancu) | Feb 2002 - Apr 2024 |
| 3. | Maksym Sobolyev (@sobomax) | Oct 2020 - Feb 2023 |
| 4. | Razvan Crainea (@razvancrainea) | Feb 2012 - Sep 2019 |
| 5. | Vlad Patrascu (@rvlad-patrascu) | May 2017 - Apr 2019 |
| 6. | Peter Lemenkov (@lemenkov) | Jun 2018 - Jun 2018 |
| 7. | Ionut Ionita (@ionutrazvanionita) | Nov 2014 - Nov 2014 |
| 8. | Anca Vamanu | Nov 2010 - Nov 2010 |
| 9. | Henning Westerholt (@henningw) | Aug 2007 - Jun 2008 |
| 10. | Daniel-Constantin Mierla (@miconda) | Apr 2006 - Mar 2008 |
All remaining contributors: Konstantin Bokarius, Edson Gellert Schubert, Andreas Heise, Elena-Ramona Modroiu, Jeffrey Magder, Jiri Kuthan (@jiriatipteldotorg), Jan Janak (@janakj), Andrei Pelinescu-Onciul.
(1) including any documentation-related commits, excluding merge commits
Last edited by: Vlad Patrascu (@rvlad-patrascu), Peter Lemenkov (@lemenkov), Liviu Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu), Razvan Crainea (@razvancrainea), Henning Westerholt (@henningw), Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Elena-Ramona Modroiu, Jan Janak (@janakj).
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