SigtranApp

SIGTRAN Application Configuration

The SIGTRAN Application is responsible for communication with all external SIGTRAN (SUA or M3UA) end points.

A single SIGTRAN Application is capable of connecting to multiple end nodes (e.g. two STP nodes in a redundant pair). Each remote node may have multiple (redundant) endpoints.

It should only be necessary to configure multiple SIGTRAN Application instances if you wish a single N2SVCD to communicate with two separate environments - e.g. with a “Test” environment and with a “Pre-Production” environment.

Here is an M3UA configuration example, operating in connect (client) mode.

<?xml version="1.0" encoding="utf-8"?>
<n2svcd>
  ...
  <applications>
    ...
    <application name="SIGTRAN" module="SigtranApp">
      <include>
        <lib>../apps/sigtran/lib</lib>
      </include>
      <parameters>
        <parameter name="ossn" value="12"/>
        <parameter name="ogt_digits" value="6421600000"/>
        <parameter name="ogt_noa" value="4"/>
        <parameter name="ogt_np" value="1"/>
        <parameter name="ogt_tt" value="0"/>
        <parameter name="default_m3ua_na" value="10"/>
      </parameters>
      <config>
        <connections>
          <connection name="peer-2057" type="m3ua" mode="connect" role="asp" next_hop_pc="400">
            <remote_host>10.42.2.155,10.42.3.155</remote_host>
            <remote_port>14001</remote_port>
            <local_host>10.42.2.100</local_host>
            <local_port>15000</local_port>
          </connection>
        </connections>
        <routes>
          <route pc="2057" connection="peer-2057"/>
          <route mingt="6421600000" maxgt="6421699999" connection="peer-2057"/>
        </routes>
      </config>
    </application>
    ...
  </application>
  ...
</n2svcd>

The SIGTRAN Application can also be run in a “Loopback” mode which is ideal for quick testing of TCAP/INAP functionality without requiring SCTP. A Loopback example is as follows:

<?xml version="1.0" encoding="utf-8"?>
<n2svcd>
  ...
  <applications>
    ...
    <application name="SIGTRAN" module="SigtranApp">
      <include>
        <lib>../apps/sigtran/lib</lib>
      </include>
      <parameters>
        <parameter name="opc" value="4114"/>
        <parameter name="ossn" value="10"/>
      </parameters>
      <config>
        <connections>
          <connection name="Loopback" type="loopback"/>
        </connections>
        <routes>
          <route pc="4114" connection="Loopback"/>
        </routes>
        <handlers>
          <handler ssn="106" service_key="3000" application="IN Script Service"/>
          <handler tcap_ac="ati3" application="IN Script Service"/>
        </handlers>
      </config>
    </application>
    ...
  </application>
  ...
</n2svcd>

Configuration Details

The application element attributes for a SIGTRAN Application instance may include the below.

For details of the various parameter types used, refer to Common Configuration.

Own Address Parameters

Every SIGTRAN Application instance must have a configured “Own Address”, even if it only uses “Loopback” connections. Specifically, it must have configured at least:

• “Own PC” (opc) and “Own SSN” (ossn), or
• “Own GT Digits” (ogt_digits)

It is possible that a SIGTRAN Application instance may have all three parameters defined, although this would be unusual. If all three parameters are present, then you may wish to explicitly define the “Own Routing Indicator” (ori) parameter.

If the “Own GT Digits” (ogt_digits) are present, then ogt_noa, ogt_np and ogt_tt may also be specified if required.

SIGTRAN Connections

SUA or M3UA Connections

Each SIGTRAN connection is defined by a connection element within the config.connections Array. Multiple connection entries may be defined. The attributes of each connection element are as follows.

Note that you may have more than once listen connection associated with a single local_host. However, some constraints apply in this case:

• The local_addresses list must be identical for all connections listening on this SCTP port.
• The remote_addresses and/or remote_port parameters must allow unambiguous identification of all inbound connection requests.

Loopback Connections

In some testing scenarios, you may wish to connect the Test Application directly to the local Script Application. In such cases you can use configure SIGTRAN with a loopback connection. All messages routed to this SCCP connection will be returned back into the service daemon.

SIGTRAN/Loopback Routes

Routing rules define which connection is used to deliver any given message. Each route Object in the config.routes Array is configured as follows.

Specify exactly one of pc OR minpc/maxpc OR gt OR mingt/maxgt. Point Code ranges are a numeric range. Global Title ranges are checked by string comparison.

You may have any number of routing rules pointing to a connection. In the case of overlapping routing rules, the SIGTRAN application will round robin between matched rules in the list with the same priority.

SIGTRAN Handlers

Handler rules apply to messages received on an Application Server (AS) Connection, i.e. a Connection where role = as. Handler rules are never applied to TCAP messages received on a Signalling Gateway (SG) Connection. TCAP messages received via a Connection where role = sg can only be relayed out on another Connection.

Any inbound TCAP messages received from an AS Connection must be configured as handled by a locally resident application. I.e. the inbound TCAP BEGIN for the transaction must match one of the Handler rules configured here.

Any subsequent TCAP CONTINUE, END, or ABORT received inbound from an AS must be associated with a TCAP Transaction ID for a previously-handled TCAP BEGIN.

Each handler Object in the config.handlers Array is configured as follows.

The handlers will be checked in order, and the first matching handler will be used.

Opcode Aliases

When specifying a handler opcode, the following case-insensitive alias values may be used instead of specifying an integer.

Message Handling

In addition to the common Application management messages, the SigtranApp uses the following messages:

• TCAP Messages (TCAP-BEGIN inbound).
• TCAP Messages (TCAP-BEGIN outbound).