use strict;
use utf8;
use XML::Parser;
use Time::Local;
use Digest::SHA1;
use MIME::Base64;
use SOAP::Lite +trace => 'debug', readable => 1;
use SOAP::WSDL;
use ConfigAdminIFService;
$SOAP::Constants::PREFIX_ENV = 'soapenv';

[...]

my $service_url='https://A.B.C.D:8443/prov/services/ConfigAdminService';
my $soap = new ConfigAdminIFService->new();
$soap->proxy($service_url);
$soap->serializer->attr({ "xmlns:con" => "config.ws.nortelnetworks.com" , "xmlns:soapenv" => "http://schemas.xmlsoap.org/soap/envelope/" });
$soap->readable(1);
my $response = $soap->call( SOAP::Data
                        ->name('getListOfSesms')
                        ->attr({ "soapenv:encodingStyle" => "http://schemas.xmlsoap.org/soap/encoding/" }),
                        $auth);