TMX Module

Daniel-Constantin Mierla

   asipto.com
   <miconda@gmail.com>

Juha Heinanen

   TutPro Inc.
   <jh@tutpro.com>

Edited by

Daniel-Constantin Mierla

   <miconda@gmail.com>

Juha Heinanen

   <jh@tutpro.com>

   Copyright © 2009 Daniel-Constantin Mierla
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Kamailio Modules
              2.2. External Libraries or Applications

        3. Parameters

              3.1. precheck_trans (int)

        4. Functions

              4.1. t_cancel_branches(which)
              4.2. t_cancel_callid(callid, cseq, flag [, rcode])
              4.3. t_reply_callid(callid, cseq, code, reason)
              4.4. t_flush_flags()
              4.5. t_flush_xflags()
              4.6. t_is_failure_route()
              4.7. t_is_branch_route()
              4.8. t_is_reply_route()
              4.9. t_is_request_route()
              4.10. t_suspend()
              4.11. t_continue(tindex, tlabel, rtname)
              4.12. t_drop([rcode])
              4.13. t_reuse_branch()
              4.14. t_precheck_trans()

        5. Exported Variables
        6. Statistics

              6.1. UAS_transactions
              6.2. UAC_transactions
              6.3. 2xx_transactions
              6.4. 3xx_transactions
              6.5. 4xx_transactions
              6.6. 5xx_transactions
              6.7. 6xx_transactions
              6.8. inuse_transactions
              6.9. active_transactions
              6.10. rpl_received
              6.11. rpl_absorbed
              6.12. rpl_relayed
              6.13. rpl_generated
              6.14. rpl_sent

   List of Examples

   1.1. precheck_trans (int)
   1.2. t_cancel_branches usage
   1.3. t_cancel_callid usage
   1.4. t_reply_callid usage
   1.5. t_flush_flags usage
   1.6. t_flush_xflags usage
   1.7. t_is_failure_route usage
   1.8. t_is_branch_route usage
   1.9. t_is_reply_route usage
   1.10. t_is_request_route usage
   1.11. t_suspend usage
   1.12. t_continue usage
   1.13. t_drop usage
   1.14. t_reuse_branch usage
   1.15. t_precheck_trans usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Kamailio Modules
        2.2. External Libraries or Applications

   3. Parameters

        3.1. precheck_trans (int)

   4. Functions

        4.1. t_cancel_branches(which)
        4.2. t_cancel_callid(callid, cseq, flag [, rcode])
        4.3. t_reply_callid(callid, cseq, code, reason)
        4.4. t_flush_flags()
        4.5. t_flush_xflags()
        4.6. t_is_failure_route()
        4.7. t_is_branch_route()
        4.8. t_is_reply_route()
        4.9. t_is_request_route()
        4.10. t_suspend()
        4.11. t_continue(tindex, tlabel, rtname)
        4.12. t_drop([rcode])
        4.13. t_reuse_branch()
        4.14. t_precheck_trans()

   5. Exported Variables
   6. Statistics

        6.1. UAS_transactions
        6.2. UAC_transactions
        6.3. 2xx_transactions
        6.4. 3xx_transactions
        6.5. 4xx_transactions
        6.6. 5xx_transactions
        6.7. 6xx_transactions
        6.8. inuse_transactions
        6.9. active_transactions
        6.10. rpl_received
        6.11. rpl_absorbed
        6.12. rpl_relayed
        6.13. rpl_generated
        6.14. rpl_sent

1. Overview

   This module collects extensions from Kamailio TM module.

   Kamailio TM (Transaction Management) module documentation is available
   at: https://www.kamailio.org/docs/modules/stable/modules/tm.html

2. Dependencies

   2.1. Kamailio Modules
   2.2. External Libraries or Applications

2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * tm - transaction management.

2.2. External Libraries or Applications

   The following libraries or applications must be installed before
   running Kamailio with this module loaded:
     * None.

3. Parameters

   3.1. precheck_trans (int)

3.1. precheck_trans (int)

   Enable/disable transaction pre-check via t_precheck_trans() function.
   If set to 0, the internal structures are not created at startup and the
   function will return false always.

   Default value is 1 (enabled).

   Example 1.1. precheck_trans (int)
...
modparam("tmx", "precheck_trans", 0)
...

4. Functions

   4.1. t_cancel_branches(which)
   4.2. t_cancel_callid(callid, cseq, flag [, rcode])
   4.3. t_reply_callid(callid, cseq, code, reason)
   4.4. t_flush_flags()
   4.5. t_flush_xflags()
   4.6. t_is_failure_route()
   4.7. t_is_branch_route()
   4.8. t_is_reply_route()
   4.9. t_is_request_route()
   4.10. t_suspend()
   4.11. t_continue(tindex, tlabel, rtname)
   4.12. t_drop([rcode])
   4.13. t_reuse_branch()
   4.14. t_precheck_trans()

4.1.  t_cancel_branches(which)

   Cancel branches of an active SIP transaction. The function can be
   called for a SIP reply that will identify the current branch.

   Parameter can be:.
     * all - cancel all branches.
     * others - cancel all branches but the current one.
     * this - cancel current branch.

   This function can be used in ONREPLY_ROUTE.

   Example 1.2. t_cancel_branches usage
...
if (t_cancel_branches("all")) {
        xlog("cancelled all branches\n");
}
...

4.2.  t_cancel_callid(callid, cseq, flag [, rcode])

   Cancel first INVITE transaction identified by callid and cseq. It sets
   the flag if the value is greater than zero

   Parameters:.
     * callid - call-id value.
     * cseq - cseq number.
     * flag - index of the flag to set.
     * rcode - code to be added as cause attribute in Reason header for
       generated CANCEL request. This parameter is optional.

   This function can be used in ANY_ROUTE.

   Example 1.3. t_cancel_callid usage
...
if (t_cancel_callid("123qaz", "5", "22")) {
        xlog("transaction cancelled\n");
}
...
if (t_cancel_callid("123qaz", "5", "22", "200")) {
        xlog("transaction cancelled with [Reason: cause=200]\n");
}
...

4.3.  t_reply_callid(callid, cseq, code, reason)

   Send reply to first transaction identified by callid and cseq.

   Parameters:.
     * callid - call-id value.
     * cseq - cseq number.
     * code - reply code.
     * reason - reply reason.

   This function can be used in ANY_ROUTE.

   Example 1.4. t_reply_callid usage
...
if (t_reply_callid("123qaz", "5", "458", "Replied remotely")) {
        xlog("transaction replied\n");
}
...

4.4.  t_flush_flags()

   Flush the flags from current SIP message into the already created
   transaction. It makes sense only in routing block if the transaction
   was created via t_newtran() and the flags have been altered since.

   It is not needed to execute this function when using t_relay() (or
   similar tm relay functions, flags are synchronized automatically in
   that case).

   This function can be used from ANY_ROUTE .

   Example 1.5. t_flush_flags usage
...
t_flush_flags();
...

4.5.  t_flush_xflags()

   Flush the extended flags from current SIP message into the already
   created transaction. It makes sense only in routing block if the
   transaction was created via t_newtran() and the extended flags have
   been altered since.

   It is not needed to execute this function when using t_relay() (or
   similar tm relay functions, xflags are synchronized automatically in
   that case).

   This function can be used from ANY_ROUTE .

   Example 1.6. t_flush_xflags usage
...
t_flush_xflags();
...

4.6.  t_is_failure_route()

   Returns true if the top-executed route block is failure_route.

   This function can be used from ANY_ROUTE .

   Example 1.7. t_is_failure_route usage
...
failure_route[xyz] {
    route(abc);
}

route[abc] {
    if(t_is_failure_route()) { ... }
}
...

4.7.  t_is_branch_route()

   Returns true if the top-executed route block is branch_route.

   This function can be used from ANY_ROUTE .

   Example 1.8. t_is_branch_route usage
...
branch_route[xyz] {
    route(abc);
}

route[abc] {
    if(t_is_branch_route()) { ... }
}
...

4.8.  t_is_reply_route()

   Returns true if the top-executed route block is reply_route.

   This function can be used from ANY_ROUTE .

   Example 1.9. t_is_reply_route usage
...
reply_route[xyz] {
    route(abc);
}

route[abc] {
    if(t_is_reply_route()) { ... }
}
...

4.9.  t_is_request_route()

   Returns true if the top-executed route block is request_route.

   This function can be used from ANY_ROUTE .

   Example 1.10. t_is_request_route usage
...
request_route[xyz] {
    route(abc);
}

route[abc] {
    if(t_is_request_route()) { ... }
}
...

4.10.  t_suspend()

   Suspend the execution of SIP request in a transaction. If transaction
   was not created yet, it is created by this function. Returns true in
   case of success and internal transaction index and label are available
   via $T(id_index) and $T(id_label).

   This function can be used from ANY_ROUTE .

   Example 1.11. t_suspend usage
...
if(t_suspend())
{
    xlog("processing suspended in transaction [$T(id_index):$T(id_label)]\n");
    exit;
}
...

4.11.  t_continue(tindex, tlabel, rtname)

   Continue the execution of the transaction identified by tindex and
   tlabel with the actions defined in route[rtname].

   Parameters:.
     * tindex - internal index of transaction. Can be an integer or a
       pseudo-variable.
     * tlabel - internal label of transaction. Can be an integer or a
       pseudo-variable.
     * rtname - the name of the route block to execute. Can be a static
       string value or a dynamic string with pseudo-variables.

   Important note: the route[rtname] is executed in the context of a
   failure (same behaviour for functions as they were used in a
   failure_route block).

   This function can be used in ANY_ROUTE.

   Example 1.12. t_continue usage
...
t_continue('123', '456', 'MYROUTE');
...
route[MYROUTE] {
  xlog("executed by t continue\n");
  ...
}
...

4.12.  t_drop([rcode])

   Drops the transaction with response code (500 default).

   Parameters:.
     * rcode - response code to set in uas status.

   This function can be used in ANY_ROUTE.

   Example 1.13. t_drop usage
...
route[MYREQ]
{
...
    if (!t_newtran()) {
        xlog("L_ERROR", "$ci|log|failed to create transaction\n");
        drop;
    }

    t_on_failure("TR_ERROR");
    t_on_reply("TR_OK");
    t_relay();
}

failure_route[TR_ERROR]
{
    xlog("L_INFO", "$ci|log|failed $T_reply_code $T_reply_reason\n");
    t_drop();
}

onreply_route[TR_OK]
{
   xlog("L_INFO", "$ci|log|checking transaction result\n");
   if(status=~"60[0-9]") {
      t_drop();
   }
...
}
...

4.13.  t_reuse_branch()

   Creates new "main" branch by making copy of branch-failure branch.
   Currently the following branch attributes are copied from
   branch-failure branch: request-uri, ruid, path, instance, and branch
   flags.

   This function can be used from tm:branch-failure event_route.

   Example 1.14. t_reuse_branch usage
...
event_route [tm:branch-failure:contact] {
    t_reuse_branch();
    setbflag(10);
    t_relay();
    exit;
}
...

4.14.  t_precheck_trans()

   Check if current processed message is handled by other process. This
   function is useful to catch retransmissions before transaction is
   created. The function returns true if the request is handled by another
   process.

   Note that ACK and CANCEL requests are not tracked by this function, the
   return code being false for them.

   This function can be used from REQUEST_ROUTE .

   Example 1.15. t_precheck_trans usage
...
    # handle retransmissions
    if(t_precheck_trans()) {
        t_check_trans();
        exit;
    }
    t_check_trans();
...

5. Exported Variables

     * $T_branch_idx
     * $T_reply_code
     * $T_reply_reason
     * $T_reply_last
     * $T_req(pv)
     * $T_rpl(pv)
     * $T_reply_ruid
     * $T_branch(name)
     * $T_inv(pv)
     * $T(name)

   Exported pseudo-variables are documented at
   https://www.kamailio.org/wikidocs/.

6. Statistics

   6.1. UAS_transactions
   6.2. UAC_transactions
   6.3. 2xx_transactions
   6.4. 3xx_transactions
   6.5. 4xx_transactions
   6.6. 5xx_transactions
   6.7. 6xx_transactions
   6.8. inuse_transactions
   6.9. active_transactions
   6.10. rpl_received
   6.11. rpl_absorbed
   6.12. rpl_relayed
   6.13. rpl_generated
   6.14. rpl_sent

   Exported statistics are listed in the next sections. These statistics
   cannot be reset (see counters module for alternative).

6.1. UAS_transactions

   Total number of transactions created by received requests.

6.2. UAC_transactions

   Total number of transactions created by local generated requests.

6.3. 2xx_transactions

   Total number of transactions completed with 2xx replies.

6.4. 3xx_transactions

   Total number of transactions completed with 3xx replies.

6.5. 4xx_transactions

   Total number of transactions completed with 4xx replies.

6.6. 5xx_transactions

   Total number of transactions completed with 5xx replies.

6.7. 6xx_transactions

   Total number of transactions completed with 6xx replies.

6.8. inuse_transactions

   Number of transactions existing in memory at current time.

6.9. active_transactions

   Number of ongoing transactions at current time.

6.10. rpl_received

   Total number of replies received by TM module.

6.11. rpl_absorbed

   Total number of replies received and not relayed by TM module.

6.12. rpl_relayed

   Total number of replies received and relayed by TM module.

6.13. rpl_generated

   Total number of replies locally generated and relayed by TM module.

6.14. rpl_sent

   Total number of replies relayed by TM module.
