This usually mean you can not access Integration Server web interface or the dial plan samples that comes with Visual Dialplan are not working properly.
In most cases this issue appears because the Integration Server is not installed as a service.

In order to install Integration Server as a service you will need to follow these steps:

1. In linux shell, go to the IS/bin directory under the directory where you installed Integration Server and run the following command:
sudo instalDeamon.sh

2. Then run this command:
service ApstelIntegrationServer start

Now you should be able to access Integration Server web interface at the following URL:

http://<local machine IP>:9111 and dial plan samples should also work correctly.