diff --git a/api/BUILD.gn b/api/BUILD.gn
index d92962c3a8..6cec2974fc 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -508,6 +508,7 @@ rtc_library("rtp_parameters") {
     ":array_view",
     ":priority",
     ":rtp_transceiver_direction",
+    "../media:media_constants",
     "../rtc_base:checks",
     "../rtc_base:stringutils",
     "../rtc_base/system:rtc_export",
diff --git a/api/rtp_parameters.cc b/api/rtp_parameters.cc
index 54132bcdbb..3ff4b58a2e 100644
--- a/api/rtp_parameters.cc
+++ b/api/rtp_parameters.cc
@@ -15,6 +15,7 @@
 #include <utility>
 
 #include "api/array_view.h"
+#include "media/base/media_constants.h"
 #include "rtc_base/strings/string_builder.h"
 
 namespace webrtc {
@@ -47,6 +48,14 @@ RtcpFeedback::~RtcpFeedback() = default;
 RtpCodec::RtpCodec() = default;
 RtpCodec::RtpCodec(const RtpCodec&) = default;
 RtpCodec::~RtpCodec() = default;
+bool RtpCodec::IsResiliencyCodec() const {
+  return name == cricket::kRtxCodecName || name == cricket::kRedCodecName ||
+         name == cricket::kUlpfecCodecName ||
+         name == cricket::kFlexfecCodecName;
+}
+bool RtpCodec::IsMediaCodec() const {
+  return !IsResiliencyCodec() && name != cricket::kComfortNoiseCodecName;
+}
 RtpCodecCapability::RtpCodecCapability() = default;
 RtpCodecCapability::~RtpCodecCapability() = default;
 
diff --git a/api/rtp_parameters.h b/api/rtp_parameters.h
index e78cc6667f..025817cf37 100644
--- a/api/rtp_parameters.h
+++ b/api/rtp_parameters.h
@@ -167,6 +167,8 @@ struct RTC_EXPORT RtpCodec {
            parameters == o.parameters;
   }
   bool operator!=(const RtpCodec& o) const { return !(*this == o); }
+  bool IsResiliencyCodec() const;
+  bool IsMediaCodec() const;
 };
 
 // RtpCodecCapability is to RtpCodecParameters as RtpCapabilities is to
diff --git a/media/base/codec.cc b/media/base/codec.cc
index fe780548cb..d18baf7132 100644
--- a/media/base/codec.cc
+++ b/media/base/codec.cc
@@ -311,7 +311,8 @@ webrtc::RtpCodecParameters Codec::ToCodecParameters() const {
 }
 
 bool Codec::IsMediaCodec() const {
-  return !IsResiliencyCodec();
+  return !IsResiliencyCodec() &&
+         !absl::EqualsIgnoreCase(name, kComfortNoiseCodecName);
 }
 
 bool Codec::IsResiliencyCodec() const {
diff --git a/pc/peer_connection_encodings_integrationtest.cc b/pc/peer_connection_encodings_integrationtest.cc
index ae238671c2..5bf29e4b19 100644
--- a/pc/peer_connection_encodings_integrationtest.cc
+++ b/pc/peer_connection_encodings_integrationtest.cc
@@ -74,15 +74,6 @@ struct StringParamToString {
   }
 };
 
-// RTX, RED and FEC are reliability mechanisms used in combinations with other
-// codecs, but are not themselves a specific codec. Typically you don't want to
-// filter these out of the list of codec preferences.
-bool IsReliabilityMechanism(const RtpCodecCapability& codec) {
-  return absl::EqualsIgnoreCase(codec.name, cricket::kRtxCodecName) ||
-         absl::EqualsIgnoreCase(codec.name, cricket::kRedCodecName) ||
-         absl::EqualsIgnoreCase(codec.name, cricket::kUlpfecCodecName);
-}
-
 std::string GetCurrentCodecMimeType(
     rtc::scoped_refptr<const RTCStatsReport> report,
     const RTCOutboundRtpStreamStats& outbound_rtp) {
@@ -163,7 +154,7 @@ class PeerConnectionEncodingsIntegrationTest : public ::testing::Test {
             .codecs;
     codecs.erase(std::remove_if(codecs.begin(), codecs.end(),
                                 [&codec_name](const RtpCodecCapability& codec) {
-                                  return !IsReliabilityMechanism(codec) &&
+                                  return !codec.IsResiliencyCodec() &&
                                          !absl::EqualsIgnoreCase(codec.name,
                                                                  codec_name);
                                 }),
diff --git a/pc/rtp_transceiver.cc b/pc/rtp_transceiver.cc
index ca626cc94b..34d744a3bb 100644
--- a/pc/rtp_transceiver.cc
+++ b/pc/rtp_transceiver.cc
@@ -51,9 +51,7 @@ RTCError VerifyCodecPreferences(
   // transceiver.direction.
 
   if (!absl::c_any_of(codecs, [&recv_codecs](const RtpCodecCapability& codec) {
-        return codec.name != cricket::kRtxCodecName &&
-               codec.name != cricket::kRedCodecName &&
-               codec.name != cricket::kFlexfecCodecName &&
+        return codec.IsMediaCodec() &&
                absl::c_any_of(recv_codecs,
                               [&codec](const cricket::Codec& recv_codec) {
                                 return recv_codec.MatchesRtpCodec(codec);
@@ -65,9 +63,7 @@ RTCError VerifyCodecPreferences(
   }
 
   if (!absl::c_any_of(codecs, [&send_codecs](const RtpCodecCapability& codec) {
-        return codec.name != cricket::kRtxCodecName &&
-               codec.name != cricket::kRedCodecName &&
-               codec.name != cricket::kFlexfecCodecName &&
+        return codec.IsMediaCodec() &&
                absl::c_any_of(send_codecs,
                               [&codec](const cricket::Codec& send_codec) {
                                 return send_codec.MatchesRtpCodec(codec);
@@ -101,11 +97,9 @@ RTCError VerifyCodecPreferences(
     }
   }
 
-  // Check we have a real codec (not just rtx, red or fec)
+  // Check we have a real codec (not just rtx, red, fec or CN)
   if (absl::c_all_of(codecs, [](const RtpCodecCapability& codec) {
-        return codec.name == cricket::kRtxCodecName ||
-               codec.name == cricket::kRedCodecName ||
-               codec.name == cricket::kUlpfecCodecName;
+        return !codec.IsMediaCodec();
       })) {
     LOG_AND_RETURN_ERROR(
         RTCErrorType::INVALID_MODIFICATION,