public abstract class ConnectionContext : IAsyncDisposable
{
  // unchanged except for IAsyncDisposable base
}

public interface IConnectionListenerFactory
{
    ValueTask<IConnectionListener> BindAsync(System.Net.EndPoint endpoint, CancellationToken cancellationToken = default);
}

public interface IConnectionListener : IAsyncDisposable
{
    EndPoint EndPoint { get; }
    ValueTask<ConnectionContext> AcceptAsync(CancellationToken cancellationToken = default);
    ValueTask UnbindAsync(CancellationToken cancellationToken = default);
}

public interface IConnectionFactory
{
    ValueTask<ConnectionContext> ConnectAsync(System.Net.EndPoint endpoint, CancellationToken cancellationToken = default);
}