l         API file location: %SugarCRM%\oss\httpd\htdocs\SugarCRM\soap.php

l         Invoke method:

1.         Create a SOAP client. PHP sample code:
$sugar_config['offline_server'] = "http://127.0.0.1/sugarpro/soap.php";
$online_soapclient = new nusoapclient($sugar_config['online_server']);

2.         Call functions. PHP sample code:
$online_soapclient->call($function_name, $params);

In this way, other systems for example ERP can call SugarCRM's functions through SOAP by indicating the name and parameters of a certain function. That has implemented communication on one direction, that is from other systems to SugarCRM. How about the method that SugatCRM call other systems? Let's research on it further.