Note: This is not implementation of https://en.wikipedia.org/wiki/Reliable_User_Datagram_Protocol
It is support:
- Constant bandwith limitation per connection.
- ping/pong logic to be sure that connection still alive
- data's packet acknowledge (delivery confirmation)
- reiteration of data packets when acknowledge is not received through some time
- limitation of attempts of data send. It can close connection, when it has many lost packets.
- asynchronous sending simple (1024 bytes) UDP packets without any acknowledge
- sending data packets as messages. So recepient will be fired when it will receive message fully
- limitation by send packets what are waiting for delivery confirmation
- internal priority of traffic (QoS). (as examples: ping has real time priority, delivery confiration has high priority, data packets has low priority )
- sync/async sending of data. Synchronous sending return control of flow when all packets with data are sended (they can be not confirmed)
- flexible bandwith for connection. It should consider full bandwith of UDP channel.
- using STUN to make UDP hole punching ( https://en.wikipedia.org/wiki/UDP_hole_punching )
p.s. Commented option is disabled, but can be enabled in the future.
% { workers_for_each_port, 1 }, %% Workers for parallel process packets for each port { listener_options, [] }, %% Socket listener options. See http://erlang.org/doc/man/gen_udp.html#open-2 { connection_timeout, 10000 }, %% Connection timeout, ms { ping_interval, 5000 }, %% Timeout to check good connection, ms { ping_packet_count, 4 }, %% Number of ping packets are sent before disconnection { delivery_timeout, 10000 }, %% Delivery timeout to check status of delivery of packet, ms { bandwith_max, 100000 }, %% Max bandwith of sender for one connection, bytes/second { bandwith_min, 100 }, %% Min bandwith of sender for one connection, bytes/second %%{ bandwith_step, 100 }, %% Bandwith step for one lost packet { max_attempts_to_send_packet, 500000 }, %% Max attempts to send packet when it can't get delivery confirmation %{ bandwith_step_increase, 10000 }, %% Step to increase bandwith, bytes %{ bandwith_check_interval, 5000 }, %% Interval to check right bandwith. %{ bandwith_step_decrease, 100 }, %% Step to decrease bandwith, bytes { send_buffer_size, 10 }, %% Number of packets inside send buffer. Sender will be stoped if this buffer is big. { udp_packet_size, 1024 } %% Max udp packet size, bytes ]} All basic functions described in gen_rudp module:
start_listener - start listener for port stop_listener - stop listener for port. connect -- connect to other host by port close -- close connection accept - start accept connection is_alive -- check is socket alive is_connected - check is socket connected to other host. controlling_process -- change controlling process for socket async_send_binary -- sends message asynchronously sync_send_binary -- sends message synchronously. This function will retunr ok only after full packet will be sended (delivery not confirmed) send_udp -- sends simple UDP message without confirmation of delivery. The maximu side for message is 1024 bytes. - { rudp_connected, Socket, Address, Port} -- made connection from Address and Port
- { rudp_closed, Socket, Reason } -- connection closed with Reason
- { rudp_received, Socket, Binary } -- received Binary