diff --git a/api/BUILD.gn b/api/BUILD.gn
index 107e57db5a..2f46c6931b 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -693,6 +693,7 @@ rtc_source_set("network_emulation_manager_api") {
     ":time_controller",
     "../call:simulated_network",
     "../rtc_base",
+    "../rtc_base:checks",
     "../rtc_base:network_constants",
     "../rtc_base:threading",
     "test/network_emulation",
diff --git a/api/test/network_emulation_manager.cc b/api/test/network_emulation_manager.cc
index 9c148a069b..6956094aa4 100644
--- a/api/test/network_emulation_manager.cc
+++ b/api/test/network_emulation_manager.cc
@@ -7,13 +7,40 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+#include "api/test/network_emulation_manager.h"
+
 #include <utility>
 
-#include "api/test/network_emulation_manager.h"
 #include "call/simulated_network.h"
+#include "rtc_base/checks.h"
 
 namespace webrtc {
 
+bool AbslParseFlag(absl::string_view text, TimeMode* mode, std::string* error) {
+  if (text == "realtime") {
+    *mode = TimeMode::kRealTime;
+    return true;
+  }
+  if (text == "simulated") {
+    *mode = TimeMode::kSimulated;
+    return true;
+  }
+  *error =
+      "Unknown value for TimeMode enum. Options are 'realtime' or 'simulated'";
+  return false;
+}
+
+std::string AbslUnparseFlag(TimeMode mode) {
+  switch (mode) {
+    case TimeMode::kRealTime:
+      return "realtime";
+    case TimeMode::kSimulated:
+      return "simulated";
+  }
+  RTC_CHECK_NOTREACHED();
+  return "unknown";
+}
+
 NetworkEmulationManager::SimulatedNetworkNode::Builder&
 NetworkEmulationManager::SimulatedNetworkNode::Builder::config(
     BuiltInNetworkBehaviorConfig config) {
diff --git a/api/test/network_emulation_manager.h b/api/test/network_emulation_manager.h
index b5c68af5f3..fcf33d947b 100644
--- a/api/test/network_emulation_manager.h
+++ b/api/test/network_emulation_manager.h
@@ -148,6 +148,16 @@ class EmulatedNetworkManagerInterface {
 
 enum class TimeMode { kRealTime, kSimulated };
 
+// Called implicitly when parsing an ABSL_FLAG of type TimeMode.
+// from the command line flag value `text`.
+// Returns `true` and sets `*mode` on success;
+// returns `false` and sets `*error` on failure.
+bool AbslParseFlag(absl::string_view text, TimeMode* mode, std::string* error);
+
+// AbslUnparseFlag returns a textual flag value corresponding to the TimeMode
+// `mode`.
+std::string AbslUnparseFlag(TimeMode mode);
+
 // Provides an API for creating and configuring emulated network layer.
 // All objects returned by this API are owned by NetworkEmulationManager itself
 // and will be deleted when manager will be deleted.