diff --git a/quic/core/congestion_control/bbr_sender.h b/quic/core/congestion_control/bbr_sender.h
index 5534144..a4d9925 100644
--- a/quic/core/congestion_control/bbr_sender.h
+++ b/quic/core/congestion_control/bbr_sender.h
@@ -110,7 +110,6 @@
   void AdjustNetworkParameters(QuicBandwidth bandwidth,
                                QuicTime::Delta rtt,
                                bool allow_cwnd_to_decrease) override;
-  void SetNumEmulatedConnections(int /*num_connections*/) override {}
   void SetInitialCongestionWindowInPackets(
       QuicPacketCount congestion_window) override;
   void OnCongestionEvent(bool rtt_updated,
diff --git a/quic/core/congestion_control/send_algorithm_interface.h b/quic/core/congestion_control/send_algorithm_interface.h
index 9db67b5..69f7455 100644
--- a/quic/core/congestion_control/send_algorithm_interface.h
+++ b/quic/core/congestion_control/send_algorithm_interface.h
@@ -45,10 +45,6 @@
   virtual void SetFromConfig(const QuicConfig& config,
                              Perspective perspective) = 0;
 
-  // Sets the number of connections to emulate when doing congestion control,
-  // particularly for congestion avoidance.  Can be set any time.
-  virtual void SetNumEmulatedConnections(int num_connections) = 0;
-
   // Sets the initial congestion window in number of packets.  May be ignored
   // if called after the initial congestion window is no longer relevant.
   virtual void SetInitialCongestionWindowInPackets(QuicPacketCount packets) = 0;
diff --git a/quic/core/congestion_control/tcp_cubic_sender_bytes.h b/quic/core/congestion_control/tcp_cubic_sender_bytes.h
index dd8be12..50f7981 100644
--- a/quic/core/congestion_control/tcp_cubic_sender_bytes.h
+++ b/quic/core/congestion_control/tcp_cubic_sender_bytes.h
@@ -49,7 +49,7 @@
   void AdjustNetworkParameters(QuicBandwidth bandwidth,
                                QuicTime::Delta rtt,
                                bool allow_cwnd_to_decrease) override;
-  void SetNumEmulatedConnections(int num_connections) override;
+  void SetNumEmulatedConnections(int num_connections);
   void SetInitialCongestionWindowInPackets(
       QuicPacketCount congestion_window) override;
   void OnConnectionMigration() override;
diff --git a/quic/core/crypto/crypto_protocol.h b/quic/core/crypto/crypto_protocol.h
index 120e99f..1534c97 100644
--- a/quic/core/crypto/crypto_protocol.h
+++ b/quic/core/crypto/crypto_protocol.h
@@ -27,7 +27,7 @@
 typedef std::string ServerConfigID;
 
 // The following tags have been deprecated and should not be reused:
-// "BBQ4", "RCID", "SREJ", "TBKP", "TB10"
+// "1CON", "BBQ4", "NCON", "RCID", "SREJ", "TBKP", "TB10"
 
 // clang-format off
 const QuicTag kCHLO = TAG('C', 'H', 'L', 'O');   // Client hello
@@ -125,7 +125,6 @@
 const QuicTag kIW10 = TAG('I', 'W', '1', '0');   // Force ICWND to 10
 const QuicTag kIW20 = TAG('I', 'W', '2', '0');   // Force ICWND to 20
 const QuicTag kIW50 = TAG('I', 'W', '5', '0');   // Force ICWND to 50
-const QuicTag k1CON = TAG('1', 'C', 'O', 'N');   // Emulate a single connection
 const QuicTag kNTLP = TAG('N', 'T', 'L', 'P');   // No tail loss probe
 const QuicTag k1TLP = TAG('1', 'T', 'L', 'P');   // 1 tail loss probe
 const QuicTag k1RTO = TAG('1', 'R', 'T', 'O');   // Send 1 packet upon RTO
diff --git a/quic/core/quic_sent_packet_manager.cc b/quic/core/quic_sent_packet_manager.cc
index d7c2c2b..ca5c7f5 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -201,9 +201,6 @@
 
   using_pacing_ = !GetQuicFlag(FLAGS_quic_disable_pacing_for_perf_tests);
 
-  if (config.HasClientSentConnectionOption(k1CON, perspective)) {
-    send_algorithm_->SetNumEmulatedConnections(1);
-  }
   if (config.HasClientSentConnectionOption(kNTLP, perspective)) {
     max_tail_loss_probes_ = 0;
   }
diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index d5ad137..075690e 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -2202,26 +2202,6 @@
                             ->GetCongestionControlType());
 }
 
-TEST_P(QuicSentPacketManagerTest, NegotiateNumConnectionsFromOptions) {
-  QuicConfig config;
-  QuicTagVector options;
-
-  options.push_back(k1CON);
-  QuicConfigPeer::SetReceivedConnectionOptions(&config, options);
-  EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
-  EXPECT_CALL(*send_algorithm_, SetNumEmulatedConnections(1));
-  EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
-  manager_.SetFromConfig(config);
-
-  QuicSentPacketManagerPeer::SetPerspective(&manager_, Perspective::IS_CLIENT);
-  QuicConfig client_config;
-  client_config.SetConnectionOptionsToSend(options);
-  EXPECT_CALL(*network_change_visitor_, OnCongestionChange());
-  EXPECT_CALL(*send_algorithm_, SetNumEmulatedConnections(1));
-  EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
-  manager_.SetFromConfig(client_config);
-}
-
 TEST_P(QuicSentPacketManagerTest, NegotiateNoMinTLPFromOptionsAtServer) {
   QuicConfig config;
   QuicTagVector options;
diff --git a/quic/test_tools/quic_test_utils.h b/quic/test_tools/quic_test_utils.h
index 85611d0..20494d7 100644
--- a/quic/test_tools/quic_test_utils.h
+++ b/quic/test_tools/quic_test_utils.h
@@ -878,7 +878,6 @@
 
   MOCK_METHOD2(SetFromConfig,
                void(const QuicConfig& config, Perspective perspective));
-  MOCK_METHOD1(SetNumEmulatedConnections, void(int num_connections));
   MOCK_METHOD1(SetInitialCongestionWindowInPackets,
                void(QuicPacketCount packets));
   MOCK_METHOD1(SetMaxCongestionWindow,