diff --git a/plugin2544/plugin/tc_throughput.py b/plugin2544/plugin/tc_throughput.py
index ec32b16..9cef0d7 100644
--- a/plugin2544/plugin/tc_throughput.py
+++ b/plugin2544/plugin/tc_throughput.py
@@ -119,7 +119,7 @@ def get_initial_boundaries(
     if throughput_conf.rate_iteration_options.result_scope.is_per_source_port:
         return [
             ThroughputBoutEntry(throughput_conf, [port_struct])
-            for port_struct in resources.port_structs
+            for port_struct in resources.tx_ports
         ]
     else:
         return [ThroughputBoutEntry(throughput_conf, resources.port_structs)]