mirror of https://github.com/sipwise/kamailio.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Victor Seva
28bb5a9977
|
13 years ago | |
|---|---|---|
| .. | ||
| doc | 13 years ago | |
| Makefile | 15 years ago | |
| README | 13 years ago | |
| sl.c | 13 years ago | |
| sl.h | 14 years ago | |
| sl_funcs.c | 14 years ago | |
| sl_funcs.h | 15 years ago | |
| sl_stats.c | 15 years ago | |
| sl_stats.h | 15 years ago | |
README
The SL Module - Statless request handling
Bogdan Iancu
FhG FOKUS
Daniel-Constantin Mierla
asipto.com
Copyright © 2003 FhG FOKUS
_________________________________________________________________
Table of Contents
1. Admin Guide
1. Overview
2. Parameters
2.1. default_code (int)
2.2. default_reason (str)
2.3. bind_tm (int)
3. Functions
3.1. sl_send_reply(code, reason)
3.2. send_reply(code, reason)
3.3. sl_reply_error()
3.4. sl_forward _reply([ code, [ reason ] ])
4. Statistics
4.1. 1xx_replies
4.2. 200_replies
4.3. 202_replies
4.4. 2xx_replies
4.5. 300_replies
4.6. 301_replies
4.7. 302_replies
4.8. 3xx_replies
4.9. 400_replies
4.10. 401_replies
4.11. 403_replies
4.12. 404_replies
4.13. 407_replies
4.14. 408_replies
4.15. 483_replies
4.16. 4xx_replies
4.17. 500_replies
4.18. 5xx_replies
4.19. 6xx_replies
4.20. xxx_replies
4.21. sent_replies
4.22. sent_err_replies
4.23. failures
4.24. received_ACKs
List of Examples
1.1. default_code example
1.2. default_reason example
1.3. bind_tm example
1.4. sl_send_reply usage
1.5. send_reply usage
1.6. sl_reply_error usage
1.7. send_reply usage
Chapter 1. Admin Guide
Table of Contents
1. Overview
2. Parameters
2.1. default_code (int)
2.2. default_reason (str)
2.3. bind_tm (int)
3. Functions
3.1. sl_send_reply(code, reason)
3.2. send_reply(code, reason)
3.3. sl_reply_error()
3.4. sl_forward _reply([ code, [ reason ] ])
4. Statistics
4.1. 1xx_replies
4.2. 200_replies
4.3. 202_replies
4.4. 2xx_replies
4.5. 300_replies
4.6. 301_replies
4.7. 302_replies
4.8. 3xx_replies
4.9. 400_replies
4.10. 401_replies
4.11. 403_replies
4.12. 404_replies
4.13. 407_replies
4.14. 408_replies
4.15. 483_replies
4.16. 4xx_replies
4.17. 500_replies
4.18. 5xx_replies
4.19. 6xx_replies
4.20. xxx_replies
4.21. sent_replies
4.22. sent_err_replies
4.23. failures
4.24. received_ACKs
1. Overview
The SL module allows the SIP server 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, ser 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 us set. As long as the timer
is valid, the incoming ACK requests will be checked using TO tag
value. Once the timer expires, all the ACK messages 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 the
server want to reply to it. Then, it will keep the current to-tag,
which will be mirrored in ACK. SER will not see its signature and
forward the ACK downstream. Caused harm is not bad--just a useless ACK
is forwarded.
2. Parameters
2.1. default_code (int)
2.2. default_reason (str)
2.3. bind_tm (int)
2.1. default_code (int)
Default reply status code.
Default value is 500.
Example 1.1. default_code example
...
modparam("sl", "default_code", 505)
...
2.2. default_reason (str)
Default reply reason phrase.
Default value is 'Internal Server Error'.
Example 1.2. default_reason example
...
modparam("sl", "default_reason", "Server Error")
...
2.3. bind_tm (int)
Controls if SL module should attempt to bind to TM module in order to
send stateful reply when the transaction is created.
Default value is 1 (enabled).
Example 1.3. bind_tm example
...
modparam("sl", "bind_tm", 0) # feature disabled
...
3. Functions
3.1. sl_send_reply(code, reason)
3.2. send_reply(code, reason)
3.3. sl_reply_error()
3.4. sl_forward _reply([ code, [ reason ] ])
3.1. sl_send_reply(code, reason)
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.
Meaning of the parameters is as follows:
* code - Return code.
* reason - Reason phrase.
Example 1.4. sl_send_reply usage
...
sl_send_reply("404", "Not found");
...
3.2. send_reply(code, reason)
For the current request, a reply is sent back having the given code
and text reason. The reply is sent stateful or stateless, depending of
the TM module: if a transaction exists for the current request, then
the reply is sent statefully, otherwise stateless.
Meaning of the parameters is as follows:
* code - Return code.
* reason - Reason phrase.
This function can be used from REQUEST_ROUTE, FAILURE_ROUTE,
BRANCH_ROUTE.
Example 1.5. send_reply usage
...
send_reply("404", "Not found");
...
send_reply("403", "Invalid user - $fU");
...
3.3. sl_reply_error()
Sends back an error reply describing the nature of the last internal
error. Usually this function should be used after a script function
that returned an error code.
Example 1.6. sl_reply_error usage
...
sl_reply_error();
...
3.4. sl_forward _reply([ code, [ reason ] ])
Forward statelessy the current received SIP reply, with the option to
change the status code and reason text. The new code has to be in the
same class. The received reply is forwarded as well by core when the
config execution ended, unless it is dropped from config.
Meaning of the parameters is as follows:
* code - Status code.
* reason - Reason phrase.
This function can be used from ONREPLY_ROUTE.
Example 1.7. send_reply usage
...
if(status=="408")
sl_forward_reply("404", "Not found");
...
4. Statistics
4.1. 1xx_replies
4.2. 200_replies
4.3. 202_replies
4.4. 2xx_replies
4.5. 300_replies
4.6. 301_replies
4.7. 302_replies
4.8. 3xx_replies
4.9. 400_replies
4.10. 401_replies
4.11. 403_replies
4.12. 404_replies
4.13. 407_replies
4.14. 408_replies
4.15. 483_replies
4.16. 4xx_replies
4.17. 500_replies
4.18. 5xx_replies
4.19. 6xx_replies
4.20. xxx_replies
4.21. sent_replies
4.22. sent_err_replies
4.23. failures
4.24. received_ACKs
4.1. 1xx_replies
Number of 1xx replies.
4.2. 200_replies
Number of 201 replies.
4.3. 202_replies
Number of 202 replies.
4.4. 2xx_replies
Number of 2xx replies.
4.5. 300_replies
Number of 300 replies.
4.6. 301_replies
Number of 301 replies.
4.7. 302_replies
Number of 302 replies.
4.8. 3xx_replies
Number of 3xx replies.
4.9. 400_replies
Number of 400 replies.
4.10. 401_replies
Number of 401 replies.
4.11. 403_replies
Number of 403 replies.
4.12. 404_replies
Number of 404 replies.
4.13. 407_replies
Number of 407 replies.
4.14. 408_replies
Number of 408 replies.
4.15. 483_replies
Number of 483 replies.
4.16. 4xx_replies
Number of 4xx replies.
4.17. 500_replies
Number of 500 replies.
4.18. 5xx_replies
Number of 5xx replies.
4.19. 6xx_replies
Number of 6xx replies.
4.20. xxx_replies
Number of replies whose code don't match any above.
4.21. sent_replies
Number of all sent replies.
4.22. sent_err_replies
Number of sent error replies.
4.23. failures
Number of failures.
4.24. received_ACKs
Number of received ACKs filtered by SL module.