# Other components

In addition to the NMS ISDN software, you need the following components to build an NMS ISDN protocol application:

- One or more NMS T1, E1, or BRI trunk interface boards

- Natural Access

Warning: | NMS Communications obtains board-level approvals certificates for supported countries. Some countries require that you obtain system-level approvals before connecting a system to the public network. To learn what approvals you require, contact the appropriate regulatory authority in the target country.

## Natural Access

Natural Access is a complete development environment for telephony applications. It provides a standard set of telephony functions grouped into logical services. Natural Access provides functions for telephony-related tasks such as call control, tone and DTMF tone generation and detection, and voice playing and recording.

Natural Access includes a service that controls switching on H.100, H.110, or MVIP-compliant devices. You can use this service to make or break connections, send patterns, and sample data. Alternatively, you can use the swish standalone utility to control switching interactively or in a batch mode.

For information about installing and using Natural Access, see the Natural Access documentation.