Alias
An alternative SIP name for a user or a service (e.g., hunt group). For example, user Joe Blow might have user ID '202' (his extension) and an alias 'jblow'. Then his SIP URIs are 'sip:202@blah.com' and 'sip:jblow@blah.com', where 'blah.com' is the SIP domain for this sipX. A user may have an unlimited number of aliases. Aliases for services are not yet supported. Aliases must be unique, and also cannot be the same as any user ID. Aliases have the same formats as user IDs.
Extension
A number that you can dial to reach a user or a service. An extension is a SIP name. Extensions are a PBX concept, not a SIP concept. SIP just knows about URIs. Practically speaking, extensions are useful because you can dial them on a numeric phone keypad. Users don't have an extension property. Rather, an extension can be assigned to a user either as their user ID (typical) or as an alias.
Extension pool
A range of numeric extensions that can be automatically assigned to users or services. Currently there is only a single user extension pool, and extensions for services must be manually assigned. Pools contain only free extensions. Once an extension has been assigned, it is no longer in the pool. Changing the pool range or disabling it therefore has no effect on extensions that have already been assigned.
Group
A collection of either users or phones that lets you organize logical groups and assign shared properties. User groups give permissions to users, for example voicemail access. Phone groups give default settings to users, for example, whether times are displayed in 12- or 24-hour format.
Line
Ties together a user, a phone, and a PBX server. A line manages calls for that user through that server.
Navigation panel
The region on the left-hand side of the sipXconfig web UI main page that contains links for administrative tasks.
PIN
A password used to log in to voicemail or to the user portal. Numeric PINs are generally recommended, since only numbers can be dialed. The superadmin PIN is an exception to this rule. For superadmin, using an alphanumeric PIN is more secure, and the superadmin user account is typically not used for making phone calls.
Profile
The collection of settings for a phone that control how the phone behaves.
SIP
The Session Initiation Protocol. See RFC 3261. SIP is an application-layer control protocol used by sipX to establish, modify, and terminate Internet telephony calls.
SIP password
A password used by the phone to register with the SIP proxy. For phones supported by sipXconfig, the SIP password entered here will be configured automatically on the phone. For unmanaged phones, the SIP password is needed when configuring lines on the phone.
Superadmin permission
Allows a user to perform privileged adminstrative tasks such as creating new users. Such users are referred to as superadmin users, a.k.a. superadmins or just admins. When sipXconfig is run for the first time, a superadmin user is automatically created, with the name 'superadmin'. This is just a convention, there is nothing special about this user compared to other superadmins.
User ID
A string that uniquely identifies a user. User IDs can contain numbers, letters, or punctuation, with some restrictions. Formally, a user ID must follow the rules for the user part of a SIP URI. See RFC 3261 for details. Typical sipX practice is to set the user ID to be the same as the user's extension, so that the extension will appear on the user's phone display. But this is not required.
User portal
The part of the sipXconfig web UI that ordinary users (non-admins) can access.