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:

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.