The ESI Communications Server supports the 48-Key IP Feature Phone II, ESI IP Cordless Handsets, VIP Softphone, and SIP phones. (See “System capacities,” page B.1, for the maximum number of IP phones that your specific ESI Communications Server will support.) The ESI-50 has a built-in IVC12. It can support up to 12 IP channels, which can be a combination of local IP, remote IP, and Esi-Link channels. The channels are activated in blocks of four for local IP, singles for remote IP, and four or twelve for Esi-Link. Here is an example of some possible ESI-50 IVC12 channel combinations: • 12 all Esi-Link. • 12 all local IP. • Eight Esi-Link, four local IP. • Four Esi-Link, four local IP, four remote IP. When two or more Intelligent VoIP Cards (IVCs)1 and the necessary licensing are installed in an ESI Communications Server, the first IVC (lowest-numbered slot) will be designated as the primary IVC, which acts as a “go-between” to associate a station to its IVC. To each IVC, the system automatically allocates 24 sequential extension numbers, as defined in the dial plan selected in Function 169.2 Therefore, the primary IVC must be connected to the same network as all of the other IVC station cards. If an IVC supports 12 IP stations, only the first 12 extension numbers can be assigned to IP stations. Programming IP stations is similar to programming digital stations, except that additional, IP networking parameters are required for the former. There are three ways IP networking parameters can be assigned to IP stations in an ESI Communications Server: • Via Function 31, as described in the following pages. • Using ESI System Programmer. • Via “setup mode” at an ESI IP Feature Phone II.