For maximum capacity without a 4-port expansion card, how many external expansion modules may be...

The Avaya IP Office IP500 V2 is a control unit that supports external expansion modules to increase capacity for trunks and extensions. Without a 4-port expansion card, the IP500 V2 supports up to 8 external expansion modules. Each module can provide additional ports for analog phones, digital stations, or trunks (e.g., DS16, DS30, or analog trunk modules). The limitation of 8 is due to the system’s backplane and power capacity without additional expansion hardware. Option A (4) is too low, Option C (14) exceeds the maximum even with a 4-port card (which allows up to 12), and Option D (18) is not supported under any configuration.References: Avaya IP Office IP500 V2 Installation Manual, Capacity Guidelines.