diff --git a/Cargo.lock b/Cargo.lock
index c1397e3..c3e87c1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -55,6 +55,8 @@ name = "hptp-send"
 version = "0.1.0"
 dependencies = [
  "hptp",
+ "thiserror",
+ "tokio",
 ]
 
 [[package]]
diff --git a/hptp-send/Cargo.toml b/hptp-send/Cargo.toml
index 128ccb3..70ae0ae 100644
--- a/hptp-send/Cargo.toml
+++ b/hptp-send/Cargo.toml
@@ -8,4 +8,6 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-hptp = { path = "../hptp" }
\ No newline at end of file
+hptp = { path = "../hptp" }
+tokio = { version = "0.2.*", features = ["rt-core", "udp"] }
+thiserror = "*"
\ No newline at end of file
diff --git a/hptp-send/src/main.rs b/hptp-send/src/main.rs
index d200e36..2f13df7 100644
--- a/hptp-send/src/main.rs
+++ b/hptp-send/src/main.rs
@@ -1,41 +1,53 @@
-use std::str::FromStr;
-
+// #![feature(backtrace)]
 extern crate hptp;
+extern crate tokio;
+#[macro_use]
+extern crate thiserror;
 
-#[derive(Debug)]
-struct Hostname {
-    ip: String,
-    port: u16,
-}
+use std::net::SocketAddrV4;
 
-struct InvalidHostnameError;
-
-impl FromStr for Hostname {
-    type Err = InvalidHostnameError;
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let i = s.find(':').ok_or(InvalidHostnameError)?;
-        Ok(Hostname {
-            ip: s[..i].into(),
-            port: s[i + 1..].parse().map_err(|_| InvalidHostnameError)?,
-        })
-    }
-}
-
-fn usage() {
-    print!("usage:\n./3700send <host-ip>:<host-port>\n")
-}
-
-fn parse_args() -> Result<Hostname, ()> {
-    std::env::args().nth(1).ok_or(())?.parse().map_err(|_| ())
+#[derive(Error, Debug)]
+enum Error {
+    #[error("invalid command-line arguments")]
+    InvalidArgs,
 }
 
 fn main() {
-    match parse_args() {
-        Ok(x) => start(x),
-        Err(_) => usage(),
+    match entry() {
+        Err(Error::InvalidArgs) => print_usage(),
+        /*
+                Err(e) => {
+                    use std::error::Error;
+                    println!("Error: {:?}", e);
+                    for bt in e.backtrace() {
+                        println!("{}", bt);
+                    }
+                }
+        */
+        Ok(()) => (),
     }
 }
 
-fn start(hn: Hostname) {
-    println!("ip={}, port={}", hn.ip, hn.port)
+fn print_usage() {
+    print!("usage:\n./3700send <host-ip>:<host-port>\n")
+}
+
+fn entry() -> Result<(), Error> {
+    let mut rt = tokio::runtime::Runtime::new().unwrap();
+    // let mut log = Logger::new();
+    rt.block_on(start())
+}
+
+async fn start() -> Result<(), Error> {
+    let addr = parse_arg()?;
+    println!("ip={}, port={}", addr.ip(), addr.port());
+    Ok(())
+}
+
+fn parse_arg() -> Result<SocketAddrV4, Error> {
+    std::env::args()
+        .nth(1)
+        .ok_or(Error::InvalidArgs)?
+        .parse()
+        .map_err(|_| Error::InvalidArgs)
 }