Using one telephone extension on multiple devices (e.g. softphone on a desktop and an SIP phone on a mobile device) is called multiple registration and it requires using special user names. To get such a user name, contact your administrator who should generate it for you.
These special user names are not required if you use desktop IP telephones. They are required in those cases where manually configured telephones are used (especially softphone applications installed on computers and SIP clients on mobile devices). If you use more than one device of this kind and want to use an identical telephone extension for all of them, ask your administrator to generate multiple
UserIDs for you (one for each device/telephone).
UserID (e.g. strings
201u2 for extension
201) should be inserted in configuration in items where your extension number would otherwise be used (
User Name on X-Lite,
User on Ekiga,
Caller ID on SJphone,
Username on Groundwire).
Apart from UserID, Display Name is usually required. You can use the original unchanged number of your extension.