Set default value for tx buffer len

packet-exchange/src/client.c

@@ -124,6 +124,7 @@ int main(int argc, char *argv[]) {
 
   main_param.refresh_rate = 50000;
   main_param.packet_priority = 3;
+  main_param.tx_buffer_len = 1024;
 
   // Process bash options
   process_options(argc, argv, &param, &main_param);