diff --git a/hptp-send/src/main.rs b/hptp-send/src/main.rs
index 2f13df7..4c2f808 100644
--- a/hptp-send/src/main.rs
+++ b/hptp-send/src/main.rs
@@ -1,53 +1,75 @@
-// #![feature(backtrace)]
+#![feature(backtrace)]
 extern crate hptp;
 extern crate tokio;
 #[macro_use]
 extern crate thiserror;
 
+use hptp::log::Logger;
 use std::net::SocketAddrV4;
 
 #[derive(Error, Debug)]
 enum Error {
+    #[error("io error: {source}")]
+    Io {
+        #[from]
+        source: tokio::io::Error,
+        backtrace: std::backtrace::Backtrace,
+    },
     #[error("invalid command-line arguments")]
     InvalidArgs,
+    #[error("did not find an available local port")]
+    NoAvailPort,
 }
 
 fn main() {
     match entry() {
         Err(Error::InvalidArgs) => print_usage(),
-        /*
-                Err(e) => {
-                    use std::error::Error;
-                    println!("Error: {:?}", e);
-                    for bt in e.backtrace() {
-                        println!("{}", bt);
-                    }
-                }
-        */
+        Err(e) => {
+            use std::error::Error;
+            println!("Error: {:?}", e);
+            for bt in e.backtrace() {
+                println!("{}", bt);
+            }
+        }
         Ok(()) => (),
     }
 }
 
 fn print_usage() {
-    print!("usage:\n./3700send <host-ip>:<host-port>\n")
+    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())
+    let mut log = Logger::new();
+    rt.block_on(start(&mut log))
 }
 
-async fn start() -> Result<(), Error> {
-    let addr = parse_arg()?;
-    println!("ip={}, port={}", addr.ip(), addr.port());
+async fn start(log: &mut Logger) -> Result<(), Error> {
+    let targ_addr = parse_args(std::env::args())?;
+    let sock = hptp::udp_retrying_bind(16, hptp::random_port)
+        .await
+        .map_err(|_| Error::NoAvailPort)?;
+    log.debug_msg(format!("bound on {}", sock.local_addr()?))
+        .await;
+    upload(log, sock, targ_addr).await?;
+    log.debug_msg("bye!").await;
     Ok(())
 }
 
-fn parse_arg() -> Result<SocketAddrV4, Error> {
-    std::env::args()
-        .nth(1)
+fn parse_args(mut args: impl Iterator<Item = String>) -> Result<SocketAddrV4, Error> {
+    args.nth(1)
         .ok_or(Error::InvalidArgs)?
         .parse()
         .map_err(|_| Error::InvalidArgs)
 }
+
+async fn upload(
+    _log: &mut Logger,
+    mut sock: tokio::net::UdpSocket,
+    targ_addr: SocketAddrV4,
+) -> Result<(), Error> {
+    sock.send_to("Hello, ".as_bytes(), targ_addr).await?;
+    sock.send_to("world!".as_bytes(), targ_addr).await?;
+    Ok(())
+}