diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 184666c..b86e194 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -787,6 +787,49 @@
     pass=1
 }
 
+# Run the current test case: start the server and if applicable the proxy, run
+# the client, wait for all processes to finish or time out.
+#
+# Inputs:
+# * $NAME: test case name
+# * $CLI_CMD, $SRV_CMD, $PXY_CMD: commands to run
+# * $CLI_OUT, $SRV_OUT, $PXY_OUT: files to contain client/server/proxy logs
+#
+# Outputs:
+# * $CLI_EXIT: client return code
+# * $SRV_RET: server return code
+do_run_test_once() {
+    # run the commands
+    if [ -n "$PXY_CMD" ]; then
+        printf "# %s\n%s\n" "$NAME" "$PXY_CMD" > $PXY_OUT
+        $PXY_CMD >> $PXY_OUT 2>&1 &
+        PXY_PID=$!
+        wait_proxy_start "$PXY_PORT" "$PXY_PID"
+    fi
+
+    check_osrv_dtls
+    printf '# %s\n%s\n' "$NAME" "$SRV_CMD" > $SRV_OUT
+    provide_input | $SRV_CMD >> $SRV_OUT 2>&1 &
+    SRV_PID=$!
+    wait_server_start "$SRV_PORT" "$SRV_PID"
+
+    printf '# %s\n%s\n' "$NAME" "$CLI_CMD" > $CLI_OUT
+    eval "$CLI_CMD" >> $CLI_OUT 2>&1 &
+    wait_client_done
+
+    sleep 0.05
+
+    # terminate the server (and the proxy)
+    kill $SRV_PID
+    wait $SRV_PID
+    SRV_RET=$?
+
+    if [ -n "$PXY_CMD" ]; then
+        kill $PXY_PID >/dev/null 2>&1
+        wait $PXY_PID
+    fi
+}
+
 # Usage: run_test name [-p proxy_cmd] srv_cmd cli_cmd cli_exit [option [...]]
 # Options:  -s pattern  pattern that must be present in server output
 #           -c pattern  pattern that must be present in client output
@@ -849,35 +892,7 @@
     while [ $TIMES_LEFT -gt 0 ]; do
         TIMES_LEFT=$(( $TIMES_LEFT - 1 ))
 
-        # run the commands
-        if [ -n "$PXY_CMD" ]; then
-            printf "# %s\n%s\n" "$NAME" "$PXY_CMD" > $PXY_OUT
-            $PXY_CMD >> $PXY_OUT 2>&1 &
-            PXY_PID=$!
-            wait_proxy_start "$PXY_PORT" "$PXY_PID"
-        fi
-
-        check_osrv_dtls
-        printf '# %s\n%s\n' "$NAME" "$SRV_CMD" > $SRV_OUT
-        provide_input | $SRV_CMD >> $SRV_OUT 2>&1 &
-        SRV_PID=$!
-        wait_server_start "$SRV_PORT" "$SRV_PID"
-
-        printf '# %s\n%s\n' "$NAME" "$CLI_CMD" > $CLI_OUT
-        eval "$CLI_CMD" >> $CLI_OUT 2>&1 &
-        wait_client_done
-
-        sleep 0.05
-
-        # terminate the server (and the proxy)
-        kill $SRV_PID
-        wait $SRV_PID
-        SRV_RET=$?
-
-        if [ -n "$PXY_CMD" ]; then
-            kill $PXY_PID >/dev/null 2>&1
-            wait $PXY_PID
-        fi
+        do_run_test_once
 
         # retry only on timeouts
         if grep '===CLIENT_TIMEOUT===' $CLI_OUT >/dev/null; then