AVAYA IP400 ATM16 - Provides an additional 16 analog ports for connection of analog trunks. Supports both loop-start and ground-start trunks. Use with ground trunks requires that the trunk module and the IP Office control unit are grounded. Provides an additional 16 analog ports for connection of analog trunks. Supports both loop-start and ground-start trunks. Use with ground trunks requires that the trunk module and the IP Office control unit are grounded.