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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

1.5. Exported Functions

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

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

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

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