diff --git a/asterisk/Asterisk_Tests.default b/asterisk/Asterisk_Tests.default
index 1de9def..503f767 100644
--- a/asterisk/Asterisk_Tests.default
+++ b/asterisk/Asterisk_Tests.default
@@ -12,6 +12,7 @@
 Asterisk_Tests_LOCAL_SIP_EMU.SIP.default_dest_port := "5060"
 Asterisk_Tests_LOCAL_SIP_EMU.SIP.default_dest_address := "127.0.0.1"
 # IMS Core:
+Asterisk_Tests_IMS_SIP_EMU.SIP.port_mode := "advanced"; # Allow concurrent client sockets
 Asterisk_Tests_IMS_SIP_EMU.SIP.default_sip_protocol := "TCP";
 Asterisk_Tests_IMS_SIP_EMU.SIP.listen_enabled := "enabled";
 Asterisk_Tests_IMS_SIP_EMU.SIP.local_sip_port := "5060"