Acc Module

Jiri Kuthan

iptel.org

Table of Contents
1. User's Guide
1.1. Overview
1.1.1. General Example
1.2. Extra accounting
1.3. Dependencies
1.4. Exported Parameters
1.4.1. secret (string)
1.4.2. log_level (integer)
1.4.3. log_fmt (string)
1.4.4. early_media (integer)
1.4.5. failed_transactions (integer)
1.4.6. log_flag (integer)
1.4.7. log_missed_flag (integer)
1.4.8. report_ack (integer)
1.4.9. report_cancels (integer)
1.4.10. radius_config (string)
1.4.11. service_type (integer)
1.4.12. radius_flag (integer)
1.4.13. radius_missed_flag (integer)
1.4.14. db_url (string)
1.4.15. db_flag (integer)
1.4.16. db_missed_flag (integer)
1.4.17. diameter_flag (integer)
1.4.18. diameter_missed_flag (integer)
1.4.19. diameter_client_host (string)
1.4.20. diameter_client_port (int)
1.4.21. log_extra (string)
1.4.22. db_extra (string)
1.4.23. rad_extra (string)
1.4.24. dia_extra (string)
1.5. Exported Functions
1.5.1. acc_log_request(comment)
1.5.2. acc_db_request(comment, table)
1.5.3. acc_rad_request(comment)
1.5.4. acc_diam_request(comment)
2. Developer's Guide
3. Frequently Asked Questions
List of Examples
1-1. Setting secret module parameter
1-2. log_level example
1-3. log_fmt example
1-4. early_media example
1-5. failed_transactions example
1-6. log_flag example
1-7. log_missed_flag example
1-8. report_ack example
1-9. report_cancels example
1-10. radius_config example
1-11. service_type example
1-12. radius_flag example
1-13. radius_missed_flag example
1-14. db_url example
1-15. db_flag example
1-16. db_missed_flag example
1-17. diameter_flag example
1-18. diameter_missed_flag example
1-19. diameter_client_host example
1-20. diameter_client_host example
1-21. log_extra example
1-22. db_extra example
1-23. rad_extra example
1-24. dia_extra example
1-25. acc_log_request usage
1-26. acc_db_request usage
1-27. acc_rad_request usage
1-28. acc_diam_request usage

Chapter 1. User's Guide

1.1. Overview

acc module is used to report on transactions to syslog, SQL and RADIUS.

To report on a transaction using syslog, use "setflag" to mark a transaction you are interested in with a flag, load accounting module and set its "log_flag" to the same flag number. The acc module will then report on completed transaction to syslog. 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.

What is printed depends on module's "log_fmt" parameter. It's a string with characters specifying which parts of request should be printed:

  • c = Call-Id

  • d = To tag (Dst)

  • f = From

  • i = Inbound Request-URI

  • m = Method

  • o = Outbound Request-URI

  • r = fRom

  • s = Status

  • t = To

  • u = digest Username

  • p = username Part of inbound Request-URI

If a value is not present in request, "n/a" is accounted instead.

Note that:

  • A single INVITE may produce multiple accounting reports -- that's due to SIP forking feature

  • Subsequent ACKs and other requests do not hit the server and can't be accounted unless record-routing is enforced. The ACKs assert very little useful information anyway and reporting on INVITE's 200 makes most accounting scenarios happy.

  • There is no session accounting -- ser maintains no sessions. If one needs to correlate INVITEs with BYEs for example for purpose of billing, then it is better done in the entity which collects accounting information. Otherwise, SIP server would have to become sessions-stateful, which would very badly impact its scalability.

  • If a UA fails in middle of conversation, a proxy will never learn 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).

Support for SQL and RADIUS works analogously. You need to enable it by recompiling the module with properly set defines. Uncomment the SQL_ACC and RAD_ACC lines in modules/acc/Makefile. To compile SQL support, you need to have mysqlclient package on your system. To compile RADIUS support, you need to have radiusclient installed on your system (version 0.4.1 or higher is required) 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). Uses along with FreeRadius (http://www.freeradius.org/) and Radiator (http://www.open.com.au/radiator/) servers have been reported to us.

Both mysql and radius libraries must be dynamically linkable. You need to configure your OS so that SER, when started, will find them. Typically, you do so by manipulating LD_LIBRARY_PATH environment variable or configuring ld.so.


1.1.1. General Example

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

if (uri=~"sip:+49") /* calls to Germany */ {
    if (!proxy_authorize("iptel.org" /* realm */,
                         "subscriber" /* table name */))  {
        proxy_challenge("iptel.org" /* realm */, "0" /* no qop */ );
        break;
    }

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

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

1.2. Extra accounting

Along the static information defined via FMT-s, ACC modules allows dynamical selection of extra information to be logged. There are two classes of information that are accessible by extra accounting: data from SIP messages (as headers) and internal SER data (as AVPs).

Selection of extra information is done via xxx_extra parameters by specifying the names of additional headers or AVPs you want to log. The syntax of is:

  • xxx_extra = extra_definition (';'extra_definition)*

  • extra_definition = log_name '=' data_type'/'data['/'flags]

  • data_type = 'hdr' | 'avp'

  • data = header_name | ['s:']AVP_name | 'i:'AVP_id

  • flags = 'g'

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.

Data can be an header name or an AVP name/ID - depending of the data_type. If header, the search for it into SIP messages will be optimized by converting at start-up the header name (string) into header type (integer) - this is not possible for all headers (only for the the most important); otherwise case insensitive string matching will be used.

The only defined flag is 'g' - global - which will force logging all values of the given header or AVP. Without this flag, only the first found value will be logged. IMPORTANT for DB logging, this flag is disabled from DB data structure constraints.


1.3. Dependencies

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 compiled with database support.


1.4. Exported Parameters

1.4.1. secret (string)

Default value is randomly generated string.

Example 1-1. Setting secret module parameter

modparam("auth", "secret", "johndoessecretphrase")

1.4.2. log_level (integer)

Log level at which accounting messages are issued to syslog.

Default value is L_NOTICE.

Example 1-2. log_level example

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

1.4.3. log_fmt (string)

Defines what parts of header fields will be printed to syslog, see "overview" for list of accepted values.

Default value is "miocfs".

Example 1-3. log_fmt example

modparam("acc", "log_fmt", "mfs")

1.4.4. early_media (integer)

Should be early media (183) accounted too ?

Default value is 0 (no).

Example 1-4. early_media example

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

1.4.5. failed_transactions (integer)

Should be failed transactions (status>=300) accounted too ?

Default value is 0 (no).

Example 1-5. failed_transactions example

modparam("acc", "failed_transactions", 1)

1.4.6. log_flag (integer)

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

Default value is 1.

Example 1-6. log_flag example

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

1.4.7. log_missed_flag (integer)

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

Default value is 2.

Example 1-7. log_missed_flag example

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

1.4.8. 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 1 (yes).

Example 1-8. report_ack example

modparam("acc", "report_ack", 0)

1.4.9. report_cancels (integer)

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

Default value is 0 (no).

Example 1-9. report_cancels example

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

1.4.10. 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.

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

Example 1-10. radius_config example

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

1.4.11. service_type (integer)

Radius service type used for accounting.

Default value is 15 (SIP).

Example 1-11. service_type example

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

1.4.12. radius_flag (integer)

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

Default value is 1.

Example 1-12. radius_flag example

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

1.4.13. radius_missed_flag (integer)

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

Default value is 2.

Example 1-13. radius_missed_flag example

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

1.4.14. db_url (string)

SQL address -- database specific.

Default value is "mysql://ser:heslo@localhost/ser"

Example 1-14. db_url example

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

1.4.15. db_flag (integer)

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

Default value is 1.

Example 1-15. db_flag example

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

1.4.16. db_missed_flag (integer)

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

Default value is 2.

Example 1-16. db_missed_flag example

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

1.4.17. diameter_flag (integer)

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

Default value is 1.

Example 1-17. diameter_flag example

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

1.4.18. diameter_missed_flag (integer)

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

Default value is 2.

Example 1-18. diameter_missed_flag example

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

1.4.19. diameter_client_host (string)

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

Default value is "localhost".

Example 1-19. diameter_client_host example

modparam("acc", "diameter_client_host", "iptel.org")

1.4.20. diameter_client_port (int)

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

Default value is 3000.

Example 1-20. diameter_client_host example

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

1.4.21. log_extra (string)

Extra values to be logged.

Default value is NULL.

Example 1-21. log_extra example

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

1.4.22. db_extra (string)

Extra values to be logged into database - DB specific.

Default value is NULL.

Example 1-22. db_extra example

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

1.4.23. rad_extra (string)

Extra values to be logged via RADIUS - RADIUS specific.

Default value is NULL.

Example 1-23. rad_extra example

modparam("acc", "rad_extra", "via=hdr/Via/g; email=avp/s:email")

1.4.24. dia_extra (string)

Extra values to be logged via DIAMETER - DIAMETER specific.

Default value is NULL.

Example 1-24. dia_extra example

modparam("acc", "dia_extra", "ct=7846/Content-type; 7847=avp/s:email")

1.5. Exported Functions

1.5.1. 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. 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.

Example 1-25. acc_log_request usage

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

1.5.2. 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.

Example 1-26. acc_db_request usage

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

1.5.3. 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.

Example 1-27. acc_rad_request usage

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

1.5.4. acc_diam_request(comment)

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

Meaning of the parameters is as follows:

  • comment - Comment to be appended.

Example 1-28. acc_diam_request usage

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

Chapter 2. Developer's Guide

To be done.


Chapter 3. Frequently Asked Questions

3.1. What is the meaning of life ?

3.1. What is the meaning of life ?

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