It is not necessary that your system name matches your IP name, which will change whenever your IP address changes. If you are away from CERN but at a site connected to the Internet, you need to ask for a connection to their internal network. Without a DHCP server you need to configure the IP parameters provided by your local site. Note that most CERN systems are not directly accessible from outside CERN so you will need to first connect to a service such as rsplus. If you need to connect from hotel rooms or other places where the callback phone number cannot be known in advance then the easiest way is to open an account with a Global Internet Access Provider.
Proprietary solutions are available for connecting mobile phones to portable PCs.
The necessary hardware, software and subscription to the data service permitting their use, is available from the Telecom Service in ST Division. Note that you cannot make modem calls to your mobile telephone number. Data calls require a separate subscription for a data number and either additional hardware or software. Long distance call costs are significantly higher. The data cards for mobile phones cost around 450 CHFs.