constrained-connection

Simulate constrained network connections.

Can be used to benchmark networking logic build on top of a stream oriented connection (e.g. TCP). Create a connection by specifying its bandwidth as well as its round trip time (delay). The connection will delay each bytes chunk by the configured delay and allow at most bandwidth-delay product number of bytes on the wire enforcing backpressure.

```rust let msg = vec![0; 10 * 1024 * 1024]; let msg_clone = msg.clone(); let start = Instant::now(); let mut pool = futures::executor::LocalPool::new();

let bandwidth = 1000000000; let rtt = Duration::frommicros(100); let (mut a, mut b) = Connection::new_constrained(bandwidth, rtt);

pool.spawner().spawnobj(async move { a.writeall(&msg_clone).await.unwrap(); }.boxed().into()).unwrap();

pool.rununtil(async { let mut receivedmsg = Vec::new(); b.readtoend(&mut received_msg).await.unwrap();

assert_eq!(msg, received_msg);

});

let duration = start.elapsed();

println!( "Bandwidth {} KiB/s, RTT {:.5} s, Payload length {} KiB, duration {:.5} s", bandwidth / 1024, rtt.assecsf64(), msg.len() / 1024, duration.assecsf64(), ); ```

For now, as the library is not properly optimized, you can not simulate high speed networks. Execute the examples/accuracy.rs binary for details.

```bash $ cargo run --example accuracy --release

Name Bandwidth RTT Payload Duration Acurracy Satellite Network 500 KiB/s 0.90000 s 10240 KiB 164.49 s 1.00 % Residential DSL 1953 KiB/s 0.05000 s 10240 KiB 42.97 s 1.02 % Mobile HSDPA 5859 KiB/s 0.10000 s 10240 KiB 14.19 s 1.01 % Residential ADSL2+ 19531 KiB/s 0.05000 s 10240 KiB 4.33 s 1.03 % Residential Cable Internet 195312 KiB/s 0.02000 s 10240 KiB 0.46 s 1.07 % GBit LAN 976562 KiB/s 0.00010 s 10240 KiB 0.26 s 3.16 % High Speed Terrestiral Net 976562 KiB/s 0.00100 s 10240 KiB 0.13 s 1.56 % Ultra High Speed LAN 97656250 KiB/s 0.00003 s 10240 KiB 0.01 s 16.08 % ```

License: Apache-2.0 OR MIT