> For the complete documentation index, see [llms.txt](https://trillbit.gitbook.io/trillbit-sdk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trillbit.gitbook.io/trillbit-sdk/features/protocols.md).

# Protocols

TrillBit's data over sound technology is facilitated through the following protocols: 

1. VoIP protocol: Transmission of data over sound via phone line.
2. Audible protocol:  Most applicable to use-cases where audibility of sound transmitted is required or desirable. 
3. Frequency of 16 KHz: Most applicable for Embedded devices supporting this sampling rate.
4. Ultrasonic protocol: This supports data transmission that is inaudible with frequencies of 17-20KHz.

Additional protocols for user specific use-case, are available on request.