Acc Module

To account a transaction and to choose which set of backends to be used, the script writer just has to set some flags (see the module parameters section for flag definitions Section 1.5). If the accouting flag for a specific backend is set, the acc module will then report on completed transaction. A typical usage of the module takes no acc-specific script command -- the functionality binds invisibly through transaction processing. Script writers just need to mark the transaction for accounting with proper setflag. Even so, the module allows the script writter to force accounting in special cases via some script functions.

The accounting module will log by default a fixed set of attributes for the transaction - if you customize your accounting by adding more information to be logged, please see the next chapter about extra accounting - Section 1.2.

The fixed minimal accounting information is:

Request Method name
From header TAG parameter
To header TAG parameter
Call-Id
3-digit Status code from final reply
Reason phrase from final reply
Time stamp when transaction was completed

If a value is not present in request, the empty string is accounted instead.

Note that:

A single INVITE may produce multiple accounting reports -- that's due to SIP forking feature.
All flags related to accounting need to be set in request processing route - only the "missed-call" flag may be toggled from other types of routes.
There is no session/dialog accounting (yet)-- OpenSER maintains no sessions. If one needs to correlate INVITEs with BYEs for generating proper CDRs for example for purpose of billing, then it is better done in the entity which processes accounting information.
If a UA fails in middle of conversation, a proxy will never find out about it. In general, a better practice is to account from an end-device (such as PSTN gateway), which best knows about call status (including media status and PSTN status in case of the gateway).

The SQL backend support is compiled in the module. For RADIUS and DIAMETER you need to enable it by recompiling the module with properly set defines: uncomment the RAD_ACC or DDIAM_ACC lines in modules/acc/Makefile. To compile RADIUS support, you need to have radiusclient-ng (only versions higher or equal to 0.5.0) installed on your system which is available from http://developer.berlios.de/projects/radiusclient-ng/. The radius client needs to be configured properly. To do so, use the template at etc/radiusclient.conf and make sure that module's radius_config parameter points to its location. In particular, accounting secret must match that one configured in server and proper dictionary is used (one is available at etc/sip_dictionary). Also note that Debian radiusclient-ng uses /var/run/radius.seq as seqfile but OpenSER Debian init script expects /var/run/openser/openser_radius.seq, so is needed to change it in radiusclient-ng configuration or in OpenSER Debian init script (if not, OpenSER can't create the seq file when not running as root). Uses along with FreeRadius ( http://www.freeradius.org/) and Radiator ( http://www.open.com.au/radiator/) servers have been reported to us.

NOTE: diameter support was developed for DISC (DIameter Server Client project at http://developer.berlios.de/projects/disc/). This project seems to be no longer maintained and DIAMETER specifications were updated in the meantime. Thus, the DIAMETER part in the module is obsolete and needs rework to be usable with opendiameter or other DIAMETER servers.

1.1.1. General Example

loadmodule "modules/acc/acc.so"
modparam("acc", "log_level", 1)
modparam("acc", "log_flag", 1)

if (uri=~"sip:+40") /* calls to Romania */ {
    if (!proxy_authorize("sip_domain.net" /* realm */,
    "subscriber" /* table name */))  {
        proxy_challenge("sip_domain.net" /* realm */, "0" /* no qop */ );
        exit;
    }

    if (method=="INVITE" & !check_from()) {
        log("from!=digest\n");
        sl_send_reply("403","Forbidden");
    }

    setflag(1); /* set for accounting (the same value as in log_flag!)
    t_relay(); 	/* enter stateful mode now */
};

1.2. Extra accounting

1.2.1. Overview

Along the static default information, ACC modules allows dynamical selection of extra information to be logged. This allows you to log any pseudo-variable (AVPs, parts of the request, etc).

1.2.2. Definitions and syntax

Selection of extra information is done via xxx_extra parameters by specifying the names of additional information you want to log. This information is defined via pseudo-variables and may include headers, AVPs values or other message or system values. The syntax of the parameter is:

xxx_extra = extra_definition (';'extra_definition)*
extra_definition = log_name '=' pseudo_variable

The full list of supported pseudo-variables in OpenSER is available at: http://openser.org/dokuwiki/doku.php/pseudovariables:devel

Via log_name you define how/where the data will be logged. Its meaning depends of the accounting support which is used:

LOG accounting - log_name will be just printed along with the data in log_name=data format;
DB accounting - log_name will be the name of the DB column where the data will be stored.IMPORTANT: add in db acc table the columns corresponding to each extra data;
RADIUS accounting - log_name will be the AVP name used for packing the data into RADIUS message. The log_name will be translated to AVP number via the dictionary. IMPORTANT: add in RADIUS dictionary the log_name attribute.
DIAMETER accounting - log_name will be the AVP code used for packing the data into DIAMETER message. The AVP code is given directly as integer, since DIAMETER has no dictionary support yet. IMPORTANT: log_name must be a number.

1.2.3. How it works

Some pseudo variables may return more than one value (like headers or AVPs). In this case, the returned values are embedded in a single string in a comma-separated format.

1.3. Multi Call-Legs accounting

1.3.1. Overview

A SIP call can have multiple legs due forwarding actions. For example user A calls user B which forwards the call to user C. There is only one SIP call but with 2 legs ( A to B and B to C). Accounting the legs of a call is required for proper billing of the calls (if C is a PSTN number and the call is billed, user B must pay for the call -as last party modifing the call destination-, and not A -as initiator of the call. Call forwarding on server is only one example which shows the necessity of the having an accounting engine with multiple legs support.

1.3.2. Configuration

First how it works: The idea is to have a set of AVPs and for each call leg to store a set of values in the AVPs. The meaning of the AVP content is stricly decided by the script writer - it can be the origin and source of the leg, its status or any other related information. If you have a set of 4 AVPS (AVP1, AVP2, AVP3, AVP4), then for the "A call B and B forwards to C" example, you need to set a different set of values for the AVPs for each leg ([A,B] and [B,C]) . The script writer must take care and properly insert all these AVP from the script (in proper order and with the correct type).

When the accounting information for the call will be written/sent, all the call-leg pairs will be added (based on the found AVP sets).

By default, the multiple call-leg support is disabled - it can be enabled just be setting the per-leg set of AVPs via the multi_leg_info module parameter.

1.3.3. Logged data

For each call, all the values of the AVP set (which defines a call-leg) will be logged. How the information will be actually logged, depends of the data backend:

syslog -- all leg-sets will be added to one record string as AVP1=xxx, AVP2=xxxx ,... sets.
database -- each pair will be separatly logged (due DB data structure constraints); several records will be written, the difference between them being only the fields corresponding to the call-leg info.
You will need to add in your DB (all acc related tables) the colums for call-leg info (a column for each AVP of the set).
Radius -- all sets will be added to the same Radius accounting message as RADIUS AVPs - for each call-leg a set of RADIUS AVPs will be added (corresponding to the per-leg AVP set)
You will need to add in your dictionary the RADIUS AVPs used in call-leg AVP set definition.
Diameter same as for RADIUS.

1.4. Dependencies

1.4.1. OpenSER Modules

The module depends on the following modules (in the other words the listed modules must be loaded before this module):

tm -- Transaction Manager
a database module -- If SQL support is used.
rr -- Record Route, if "detect_direction" module parameter is enabled.

1.4.2. External Libraries or Applications

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

radiusclient-ng 0.5.0 or higher -- if compiled with RADIUS support. See http://developer.berlios.de/projects/radiusclient-ng/.

1.5. Exported Parameters

1.5.1. `early_media` (integer)

Should be early media (183) accounted too ?

Default value is 0 (no).

Example 1-1. early_media example

modparam("acc", "early_media", 1)

1.5.2. `failed_transaction_flag` (integer)

Per transaction flag which says if the transaction should be accounted also in case of failure (status>=300).

Default value is not-set (no flag).

Example 1-2. failed_transaction_flag example

modparam("acc", "failed_transaction_flag", 4)

1.5.3. `report_ack` (integer)

Shall acc attempt to account e2e ACKs too ? Note that this is really only an attempt, as e2e ACKs may take a different path (unless RR enabled) and mismatch original INVITE (e2e ACKs are a separate transaction).

Default value is 0 (no).

Example 1-3. report_ack example

modparam("acc", "report_ack", 1)

1.5.4. `report_cancels` (integer)

By default, CANCEL reporting is disabled -- most accounting applications wants to see INVITE's cancellation status. Turn on if you explicitly want to account CANCEL transactions.

Default value is 0 (no).

Example 1-4. report_cancels example

modparam("acc", "report_cancels", 1)

1.5.5. `detect_direction` (integer)

Controlles the direction detection for sequential requests. If enabled (non zero value), for sequential requests with upstream direction (from callee to caller), the FROM and TO will be swapped (the direction will be preserved as in the original request).

It affects all values related to TO and FROM headers (body, URI, username, domain, TAG).

Default value is 0 (disabled).

Example 1-5. detect_direction example

modparam("acc", "detect_direction", 1)

1.5.6. `multi_leg_info` (string)

Defines the AVP set to be used in per-call-leg accounting. See Section 1.3 for a detailed description of the Multi Call-Legs accounting.

If empty, the multi-leg accouting support will be disabled.

Default value is 0 (disabled).

Example 1-6. multi_leg_info example

# for syslog-based accouting, use any text you want to be printed
modparam("acc", "multi_leg_info",
    "text1=$avp(src);text2=$avp(dst)")
# for mysql-based accouting, use the names of the columns
modparam("acc", "multi_leg_info",
    "leg_src=$avp(src);leg_dst=$avp(dst)")
# for RADIUS-based accouting, use the names of the RADIUS AVPs
modparam("acc", "multi_leg_info",
    "RAD_LEG_SRC=$avp(src);RAD_LEG_SRC=$avp(dst)")
# for DIAMETER-based accouting, use the DIAMETER AVP ID (as integer)
modparam("acc", "multi_leg_info",
    "2345=$avp(src);2346=$avp(dst)")

1.5.7. `log_flag` (integer)

Request flag which needs to be set to account a transaction via syslog.

Default value is not-set (no flag).

Example 1-7. log_flag example

modparam("acc", "log_flag", 2)

1.5.8. `log_missed_flag` (integer)

Request flag which needs to be set to account missed calls via syslog.

Default value is not-set (no flag).

Example 1-8. log_missed_flag example

modparam("acc", "log_missed_flag", 3)

1.5.9. `log_level` (integer)

Log level at which accounting messages are issued to syslog.

Default value is L_NOTICE.

Example 1-9. log_level example

modparam("acc", "log_level", 2)   # Set log_level to 2

1.5.10. `log_extra` (string)

Extra values to be logged.

Default value is NULL.

Example 1-10. log_extra example

modparam("acc", "log_extra", "ua=$hdr(User-Agent);uuid=$avp(i:123)")

1.5.11. `radius_config` (string)

This parameter is radius specific. Path to radius client configuration file, set the referred config file correctly and specify there address of server, shared secret (should equal that in /usr/local/etc/raddb/clients for freeRadius servers) and dictionary, see etc for an example of config file and dictionary.

If the parameter is set to empty string, the RADIUS accouting support will be disabled (even if compiled).

Default value is "/usr/local/etc/radiusclient/radiusclient.conf ".

Example 1-11. radius_config example

modparam("acc", "radius_config", "/etc/radiusclient/radiusclient.conf")

1.5.12. `radius_flag` (integer)

Request flag which needs to be set to account a transaction -- RADIUS specific.

Default value is not-set (no flag).

Example 1-12. radius_flag example

modparam("acc", "radius_flag", 2)

1.5.13. `radius_missed_flag` (integer)

Request flag which needs to be set to account missed calls -- RADIUS specific.

Default value is not-set (no flag).

Example 1-13. radius_missed_flag example

modparam("acc", "radius_missed_flag", 3)

1.5.14. `service_type` (integer)

Radius service type used for accounting.

Default value is 15 (SIP).

Example 1-14. service_type example

modparam("acc", "service_type", 16)

1.5.15. `radius_extra` (string)

Extra values to be logged via RADIUS - RADIUS specific.

Default value is NULL.

Example 1-15. radius_extra example

modparam("acc", "radius_extra", "via=$hdr(Via[*]); email=$avp(s:email)")

1.5.16. `db_flag` (integer)

Request flag which needs to be set to account a transaction -- database specific.

Default value is not-set (no flag).

Example 1-16. db_flag example

modparam("acc", "db_flag", 2)

1.5.17. `db_missed_flag` (integer)

Request flag which needs to be set to account missed calls -- database specific.

Default value is not-set (no flag).

Example 1-17. db_missed_flag example

modparam("acc", "db_missed_flag", 3)

1.5.18. `db_table_acc` (string)

Table name of accounting successfull calls -- database specific.

Default value is "acc"

Example 1-18. db_table_acc example

modparam("acc", "db_table_acc", "myacc_table")

1.5.19. `db_table_missed_calls` (string)

Table name for accounting missed calls -- database specific.

Default value is "missed_calls"

Example 1-19. db_table_missed_calls example

modparam("acc", "db_table_missed_calls", "myMC_table")

1.5.20. `db_url` (string)

SQL address -- database specific. If is set to NULL or emty string, the SQL support is disabled.

Default value is "NULL" (SQL disabled).

Example 1-20. db_url example

modparam("acc", "db_url", "mysql://user:password@localhost/openser")

1.5.21. `acc_method_column` (string)

Column name in accouting table to store the request's method name as string.

Default value is "method".

Example 1-21. acc_method_column example

modparam("acc", "acc_method_column", "method")

1.5.22. `acc_from_tag_column` (string)

Column name in accouting table to store the From header TAG parameter.

Default value is "from_tag".

Example 1-22. acc_from_tag_column example

modparam("acc", "acc_from_tag_column", "from_tag")

1.5.23. `acc_to_tag_column` (string)

Column name in accouting table to store the To header TAG parameter.

Default value is "to_tag".

Example 1-23. acc_to_tag_column example

modparam("acc", "acc_to_tag_column", "to_tag")

1.5.24. `acc_callid_column` (string)

Column name in accouting table to store the request's Callid value.

Default value is "callid".

Example 1-24. acc_callid_column example

modparam("acc", "acc_callid_column", "callid")

1.5.25. `acc_sip_code_column` (string)

Column name in accouting table to store the final reply's numric code value in string format.

Default value is "sip_code".

Example 1-25. acc_sip_code_column example

modparam("acc", "acc_sip_code_column", "sip_code")

1.5.26. `acc_sip_reason_column` (string)

Column name in accouting table to store the final reply's reason phrase value.

Default value is "sip_reason".

Example 1-26. acc_sip_reason_column example

modparam("acc", "acc_sip_reason_column", "sip_reason")

1.5.27. `acc_time_column` (string)

Column name in accouting table to store the time stamp of the transaction completion in date-time format.

Default value is "time".

Example 1-27. acc_time_column example

modparam("acc", "acc_time_column", "time")

1.5.28. `db_extra` (string)

Extra values to be logged into database - DB specific.

Default value is NULL.

Example 1-28. db_extra example

modparam("acc", "db_extra", "ct=$hdr(Content-type); email=$avp(s:email)")

1.5.29. `diameter_flag` (integer)

Request flag which needs to be set to account a transaction -- DIAMETER specific.

Default value is not-set (no flag).

Example 1-29. diameter_flag example

modparam("acc", "diameter_flag", 2)

1.5.30. `diameter_missed_flag` (integer)

Request flag which needs to be set to account missed calls -- DIAMETER specific.

Default value is not-set (no flag).

Example 1-30. diameter_missed_flag example

modparam("acc", "diameter_missed_flag", 3)

1.5.31. `diameter_client_host` (string)

Hostname of the machine where the DIAMETER Client is running -- DIAMETER specific.

Default value is "localhost".

Example 1-31. diameter_client_host example

modparam("acc", "diameter_client_host", "3a_server.net")

1.5.32. `diameter_client_port` (int)

Port number where the Diameter Client is listening -- DIAMETER specific.

Default value is 3000.

Example 1-32. diameter_client_host example

modparam("acc", "diameter_client_port", 3000)

1.5.33. `diameter_extra` (string)

Extra values to be logged via DIAMETER - DIAMETER specific.

Default value is NULL.

Example 1-33. diameter_extra example

modparam("acc", "diameter_extra", "7846=$hdr(Content-type);7847=$avp(s:email)")

1.6. Exported Functions

1.6.1. `acc_log_request(comment)`

acc_request reports on a request, for example, it can be used to report on missed calls to off-line users who are replied 404 - Not Found. To avoid multiple reports on UDP request retransmission, you would need to embed the action in stateful processing.

Meaning of the parameters is as follows:

comment - Comment to be appended.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1-34. acc_log_request usage

...
acc_log_request("Some comment");
...

1.6.2. `acc_db_request(comment, table)`

Like acc_log_request, acc_db_request reports on a request. The report is sent to database at "db_url", in the table referred to in the second action parameter.

Meaning of the parameters is as follows:

comment - Comment to be appended.
table - Database table to be used.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1-35. acc_db_request usage

...
acc_log_request("Some comment", "Some table");
...

1.6.3. `acc_rad_request(comment)`

Like acc_log_request, acc_rad_request reports on a request. It reports to radius server as configured in "radius_config".

Meaning of the parameters is as follows:

comment - Comment to be appended.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1-36. acc_rad_request usage

...
acc_rad_request("Some comment");
...

1.6.4. `acc_diam_request(comment)`

Like acc_log_request, acc_diam_request reports on a request. It reports to the configured Diameter server.

Meaning of the parameters is as follows:

comment - Comment to be appended.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1-37. acc_diam_request usage

...
acc_diam_request("Some comment");
...

Chapter 2. Developer's Guide

The module does not provide any API to use in other OpenSER modules.

Chapter 3. Frequently Asked Questions

3.1. What happend with old log_fmt parameter
3.2. What happend with old multi_leg_enabled parameter
3.3. What happend with old src_leg_avp_id & dst_leg_avp_id parameters
3.4. Where can I find more about OpenSER?
3.5. Where can I post a question about this module?
3.6. How can I report a bug?

3.1. What happend with old log_fmt parameter

The parameter became obsolete with the restructure of the data logged by ACC module (refer to the Overview chapter). For similar behaviour you can use the extra accouting (see the coresponding chapter).

3.2. What happend with old multi_leg_enabled parameter

The parameter becaome obsolete by the addition of the new multi_leg_info parameter. The multi-leg accouting is automatically enabled when multi_leg_info is defined.

3.3. What happend with old src_leg_avp_id & dst_leg_avp_id parameters

The parameter was replaced by the more generic new parameter multi_leg_info. This allows logging (per-leg) of more information than just dst and src.

3.4. Where can I find more about OpenSER?

Take a look at http://www.openser-project.org/.

3.5. 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.openser-project.org/cgi-bin/mailman/listinfo/users
Developer Mailing List - http://lists.openser-project.org/cgi-bin/mailman/listinfo/devel

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

If you want to keep the mail private, send it to <team@lists.openser-project.org>.

3.6. How can I report a bug?

Please follow the guidelines provided at: http://sourceforge.net/tracker/?group_id=139143.