# decibel v1.2.1 - Table of Contents

## Pages

- Getting started
  - [Getting Started](getting-started.md)
  - [Security](security.md)

- Advanced guides
  - [Connectionless Transports](connectionless-transports.md)
  - [Noise Pipes](noise-pipes.md)

- Project information
  - [Upgrading to Decibel 1.0](upgrading-to-1-0.md)
  - [Changelog](changelog.md)

## Modules

- [Decibel](Decibel.md): `Decibel` is an implementation of [The Noise Protocol Framework](https://noiseprotocol.org).
- [Decibel.Handoff](Decibel.Handoff.md): An opaque, single-use ticket for transferring an in-progress handshake.
- [Decibel.ReplayWindow](Decibel.ReplayWindow.md): An immutable replay window for connectionless transports.
- [Decibel.Session](Decibel.Session.md): An opaque, process-owned Decibel session handle.

- Exceptions
  - [Decibel.DecryptionError](Decibel.DecryptionError.md): Raised when a peer message cannot be decrypted or processed safely.
  - [Decibel.HandoffError](Decibel.HandoffError.md): Raised when a handshake handoff cannot be created or accepted.
  - [Decibel.NonceError](Decibel.NonceError.md): Raised when a cipher nonce is exhausted, a caller supplies an invalid nonce,
or an outbound nonce would move backwards.
  - [Decibel.SessionError](Decibel.SessionError.md): Raised when a session handle cannot be used for an operation.
  - [Decibel.TransportDirectionError](Decibel.TransportDirectionError.md): Raised when an operation targets the discarded direction of a one-way
transport.