N2SVCD Configuration - 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 SUA 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"/>
      </parameters>
      <config>
        <connections>
          <connection name="peer-2057" type="sua" mode="connect" role="as">
            <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" application="IN Script Service"/>
        </handlers>
      </config>
    </application>
    ...
  </application>
  ...
</n2svcd>

The application element attributes for a SIGTRAN Application instance are:

Attribute	Type	Description
name	String	[Required] A unique name for this application instance.
module	String	[Required] SigtranApp
include.lib	String	[Required] ../apps/sigtran/lib
parameters	Array	Array of name = value Parameters for this Application instance.
.correlation_id_len	Integer	The number of digits for each CorrelationID in the ID Pool. (Default = 4).
.ori	Integer	The SCCP "Own Routing Indicator" for outbound TCAP BEGIN messages. (Default = 1 if opc and ossn are specified) (Default = 0 otherwise).
.ossn	Integer	The SCCP "Own Sub-System Number" for outbound TCAP BEGIN messages (in Decimal format). (Range = 1-255).
.opc	Integer	The SCCP "Own Point Code" for outbound TCAP BEGIN messages. (Range = 0-16383 ITU, 0-16777215 ANSI).
.ogt_digits	String	The SCCP "Own Global Title Digits" for outbound TCAP BEGIN messages.
.ogt_noa	Integer	The SCCP "Own Global Title Nature of Address" for outbound TCAP BEGIN messages. (Range = 0-127).
.ogt_np	Integer	The SCCP "Own Global Title Numbering Plan" for outbound TCAP BEGIN messages. (Range = 0-7).
.ogt_tt	Integer	The SCCP "Own Global Title Translation Type" for outbound TCAP BEGIN messages. (Range = 0-255).
.tcap_pv	Integer	Specify 1 to enable the specification of TCAP Protocol Version to all outbound TCAP messages which include an Application Context. (Values = 0 or 1, Default = 0 do not enable).
.sndrcv_buffer	Integer	Override the system default SCTP Send/Receive buffers size (in bytes). The default SCTP buffers will likely be insufficient for sustained load testing or high throughput. Under sustained loads, a value of at least 1048576 bytes (or higher) is recommended. You will very likely also need to increment the sysctl values for net.core.rmem_max and net.core.wmem_max on your platform. This may be further over-ridden on a per-Connection bases. (Default = Use System Socket Defaults).
.sinit_num_ostreams	Integer	Override the system default SCTP sinit_num_ostreams. This may be further over-ridden on a per-Connection bases. (Default = Use End-Point Default).
.sinit_max_instreams	Integer	Override the system default SCTP sinit_max_instreams. This may be further over-ridden on a per-Connection bases. (Default = Use End-Point Default).
.sinit_max_attempts	Integer	Override the system default SCTP sinit_max_attempts. This may be further over-ridden on a per-Connection bases. (Default = Use End-Point Default, typically Max.Init.Retransmit).
.sinit_max_init_timeo	Integer	Override the system default SCTP sinit_max_init_timeo. This may be further over-ridden on a per-Connection bases. (Default = Use End-Point Default, typically RTO.Max).
config	Object	Container for extended configuration for this Application instance.
.connections	Array	Array of connection elements defining SIGTRAN communication paths.
.routes	Array	Array of route elements, rules for selecting connections for outbound delivery.
.handlers	Array	Array of handler elements, rules for selecting the owning Application for inbound TCAP BEGIN messages.

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). If not specified, the ori will default to 1 if opc and ossn are both present, or 0 otherwise.

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)

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.

Attribute	Type	Description
name	String	[Required] A unique name for this connection.
type	String	[Required] Our SIGTRAN protocol: sua or m3ua.
mode	String	Our SCTP socket mode: connect or listen . (Default = connect).
sndrcv_buffer	Integer	Override the system/application default SCTP Send/Receive buffers size (in bytes). See the comments on the corresponding parameter at the SIGTRAN Application level. (Default = Use System/Application Defaults).
sinit_num_ostreams	Integer	Override the system/application default SCTP INIT sinit_num_ostreams. See the comments on the corresponding parameter at the SIGTRAN Application level. (Default = Use System/Application Defaults).
sinit_max_instreams	Integer	Override the system/application default SCTP INIT sinit_max_instreams. See the comments on the corresponding parameter at the SIGTRAN Application level. (Default = Use System/Application Defaults).
sinit_max_attempts	Integer	Override the system/application default SCTP INIT sinit_max_attempts. See the comments on the corresponding parameter at the SIGTRAN Application level. (Default = Use System/Application Defaults).
sinit_max_init_timeo	Integer	Override the system/application default SCTP INIT sinit_max_init_timeo. See the comments on the corresponding parameter at the SIGTRAN Application level. (Default = Use System/Application Defaults).
role	String	Our role in the relationship: as or sg. (Default = as).
remote_port	Integer	IPv4 Port Number. Mandatory for SCTP mode = connect.
remote_addresses	String	IPv4 Host Names or A.B.C.D IPv4 Addresses. Mandatory for mode = connect. May be a single address for the end-point, or a comma-separated multi-homed list.
remote_host	String	An alternative attribute name for remote_addresses.
local_port	Integer	IPv4 Port Number. Mandatory for SCTP mode = listen.
local_addresses	String	IPv4 Host Name or A.B.C.D IPv4 Address. Mandatory for mode = listen. May be a single address for the end-point, or a comma-separated multi-homed list.
local_host	String	An alternative attribute name for local_addresses.
.address	Object	Object defining a local SIGTRAN endpoint. See documentation below.
sg_dpc	Integer	Signalling Gateway (next-hop) Destination Point Code. Typically required if and only if we are an AS connecting to an SG. (Range = 0-16383 ITU, 0-16777215 ANSI).
mtp3_ni	Integer	MTP3 Network Indicator parameter. Range 0..3, default = 2 [national] (Applies only to m3ua connections).
rc	Integer	Routing Context. Required only if the far end is not configured to supply it. In general, the RC is not required when connecting to an SG. It is typically required when we are acting as an SG in a direct connection to OCNCC.

SIGTRAN Connections (Loopback)

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.

Attribute	Type	Description
name	String	[Required] A unique name for this connection.
type	String	[Required] loopback

SIGTRAN Routes

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

Attribute	Type	Description
connection	String	[Required] The name of the Connection to deliver matching messages.
pc	Integer	A single Point Code to route. (Range = 0-16383 ITU, 0-16777215 ANSI).
minpc	Integer	Start (inclusive) of a Point Code range to route. (Range = 0-16383 ITU, 0-16777215 ANSI).
maxpc	Integer	End (inclusive) of a Point Code range to route. (Range = 0-16383 ITU, 0-16777215 ANSI).
gt	String	A single Global Title to route.
mingt	String	Start (inclusive) of a Global Title range to route.
maxgt	String	End (inclusive) of a Global Title range to route.

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 first matching rule in the list will be used.

SIGTRAN Handlers

Handler rules define which application is used to process an inbound TCAP BEGIN. Each handler Object in the config.handlers Array is configured as follows.

Attribute	Type	Description
ssn	Integer	The local SSN to which the TCAP BEGIN was directed. (Default = Match all SSN)
application	String	The name of the application which should process matching TCAP BEGIN operations. This will normally refer to a ScriptApp instance.

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