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lucaspoffo / renet

Server/Client network library for multiplayer games with authentication and connection management made with Rust
Apache License 2.0
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Add delay for ack packets #156

Open lucaspoffo opened 3 months ago

lucaspoffo commented 3 months ago

Currently, renet sends acks every update frame, this increases the bandwidth for connections.

This PR adds a delay for sending ACK packets, when receiving a reliable message this delay is ignored and the ACK is sent immediatly (so we don't delay acks for reliable messages).

This reduces the bandwidth of connections. For idle connections this seems to reduce from 2.15 kbps to 0.5 kbps (at 60 hz and 200ms max delay). If the connection is receiving reliable messages every frame this PR will not change the bandwidth since it will still send ACKs every frame.

This change will affect a bit the stats for the connection , since the values can be delaye, but at small MAX_ACK_DELAY ( 200-300ms), this shouldn't impact much.

TODO: make sure the RTT calculations is working correctly and check that the new delay field in the ACK packet cannot be wrongly used with malicious packets.

UkoeHB commented 3 months ago

Why put the ack delay in the ack packet, and not as a config? This makes ack packets bigger and adds risk of malicious effects. It also breaks from the netcode standard.