Sangoma NetBorder Call Analyzer - Answering Machine Detection

This document contains basic information on how to set up Brekeke PBX to work with Sangoma NetBorder Call Analyzer.
For more information about Sangoma product, please visit


Configure Sangoma NetBorder Call Analyzer

The default port where Sangoma Netborder Call Analyzer is listening for SIP connections is 5062.

It will be easier for configuration if the machine has only one IP address where Sangoma NetBorder Call Analyzer is running.

With default setting at Sangoma configuration, parameter “;cpd=on” is quired in the initial INVITE request URL to perform Call Analysis (CPA), like INVITE sip:1000@;cpd=on SIP/2.0

By changing the following variable setting to “false” in Sangoma configuration file “”, all calls will have call analysis performed.



Configure Brekeke PBX

With the following setup, all outbound calls will be sent through Sangoma NetBorder Call Analyzer to the destinaiton to detect if the calls are answered by answering machine. If “Answering-Machine” is in the CPD-Result header in the 200OK sent from the Sangoma NetBorder Call Analyzer for the initial INVITE sent from Brekeke PBX, Brekeke PBX can reject the call.


Dial Plan rule to forward outbound calls to Sangoma
[Matching Patterns]
$pbx.src = ^true
$request = ^INVITE
$outbound = true

[Deploy Patterns]
$target = <Sangoma_IP_address>:5062
$auth = false
$b2bua = true
&net.sip.replace.callid = false
$replaceuri = false

Put the above rule on the top of other dial plan rules and replace <Sangoma_IP_address> with real IP address which is assigned to Sangoma NetBorder Call Analyzer.


Brekeke PBX setting

Set the following variable from Brekeke PBX Admintool > [PBX Admin] > [Options] > [Advanced] page,
Brekeke PBX will disconnect the outbound calls which are answered by answering machine, which is indicated from the “CPD-Result” header in the 200 OK sent from Sangoma for the INVITE.


Save the setting and restart Brekeke PBX from Admintool to make changes take effect.

The default setting for above variable is false, which means Brekeke PBX will connect all calls even the calls are answered by answering machine.

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