# Uses of Package
net.i2p.router.transport.udp

- Packages that use net.i2p.router.transport.udp
  Package | Description
  --- | ---
  net.i2p.router.transport.udp | The UDP transport (also known as 'SSU' or Secure Semi-reliable UDP transport) for I2P, allowing I2P messages to be passed over UDP connections.
  net.i2p.router.web.helpers | Helpers and handlers for the router console user interface, with these classes supporting the webapp in routerconsole.war.

- Classes in net.i2p.router.transport.udp used by net.i2p.router.transport.udp
  Class and Description
  ACKBitfield Generic means of SACK/NACK transmission for partially or fully received messages
  EstablishmentManager Coordinate the establishment of new sessions - both inbound and outbound.
  EstablishmentManager.Token Token used for SSU2 session establishment and validation.
  InboundEstablishState Data for a new connection being established, where the remote peer has initiated the connection with us.
  InboundEstablishState.InboundState States for inbound SSU session establishment.
  InboundEstablishState2 Data for a new connection being established, where the remote peer has initiated the connection with us.
  InboundMessageFragments Organize the received data message fragments, feeding completed messages to the `MessageReceiver` and telling the `PeerState` to ACK.
  InboundMessageState Hold the raw data fragments of an inbound message.
  IntroductionManager Keep track of inbound and outbound introductions.
  OutboundEstablishState Data for a new connection being established, where we initiated the connection with a remote peer.
  OutboundEstablishState.OutboundState States for outbound SSU session establishment.
  OutboundEstablishState2 Data for a new connection being established, where we initiated the connection with a remote peer.
  OutboundEstablishState2.IntroState Per-introducer introduction states
  OutboundMessageFragments Coordinate the outbound fragments and select the next one to be built.
  OutboundMessageState Maintain the outbound fragmentation for resending, for a single message.
  PacketBuilder.Fragment Class for passing multiple fragments to buildPacket()
  PacketBuilder2 Builds and encrypts SSU2 protocol packets for UDP transport.
  PacketHandler Pull inbound packets from the inbound receiver's queue, figure out what peer session they belong to (if any), authenticate and decrypt them with the appropriate keys, and push them to the appropriate handler.
  PeerState Contain all of the state about a UDP connection to a peer.
  PeerState2 Contain all of the state about a UDP connection to a peer.
  PeerStateDestroyed Small, stub version of PeerState2, for handling destroy acks with possible tokens in them.
  PeerTestManager Entry points are runTest() to start a new test as Alice, and receiveTest() for all received test packets.
  PeerTestState.Role Roles for peer testing scenarios.
  RemoteHostId Unique ID for a peer - its IP + port, all bundled into a tidy obj.
  SocketListener Listener for socket events.
  SSU2Bitfield Container of a long array representing set and unset bits.
  SSU2Bitfield.Callback Callback interface for bitfield operations.
  SSU2Header.Header A temporary structure returned from trial decrypt, with methods to access the fields.
  SSU2Payload.AckBlock Block containing acknowledgment data.
  SSU2Payload.Block Base class for blocks to be transmitted.
  SSU2Payload.PayloadCallback For all callbacks, recommend throwing exceptions only from the handshake.
  SSU2Sender Basic interface over top of PeerState2 and PeerStateDestroyed, so we can pass them both to PacketBuilder2 to send packets.
  UDPAddress UDP address parser and validator for I2P peer information.
  UDPEndpoint Coordinate the low-level datagram socket, creating and managing the UDPSender and UDPReceiver.
  UDPPacket UDP packet wrapper with caching and metadata support.
  UDPSender Lowest level UDP packet sender that pushes packets from its queue ASAP.
  UDPTransport Secure Semi-reliable UDP (SSU) transport implementation for I2P.

- Classes in net.i2p.router.transport.udp used by net.i2p.router.web.helpers
  Class and Description
  PeerState Contain all of the state about a UDP connection to a peer.