1 files changed, 93 insertions, 0 deletions
diff --git a/libtransport/src/protocols/rtc/rtc_rc_iat.h b/libtransport/src/protocols/rtc/rtc_rc_iat.h
new file mode 100644
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+++ b/libtransport/src/protocols/rtc/rtc_rc_iat.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2021 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+#include <hicn/transport/utils/shared_ptr_utils.h>
+#include <protocols/rtc/rtc_rc.h>
+
+namespace transport {
+
+namespace protocol {
+
+namespace rtc {
+
+const int ROUND_HISTORY_SIZE = 10;  // equivalent to two seconds
+const int ROUND_TO_WAIT_FORCE_DECISION = 5;
+
+// once congestion is gone, we need to wait for k rounds before changing the
+// congestion cause in the case it appears again
+const int ROUND_TO_RESET_CAUSE = 5;
+
+const int MIN_IST_VALUE = 150;  // samples of ist larger than 150ms are
+                                // discarded
+const double CONGESTION_FREE_QUEUEING_DELAY = 10;
+
+enum class CongestionCause : uint8_t {
+  COMPETING_CROSS_TRAFFIC,
+  FRIENDLY_CROSS_TRAFFIC,
+  UNKNOWN_CROSS_TRAFFIC,
+  LINK_CAPACITY,
+  UNKNOWN
+};
+
+class RTCRateControlIAT : public RTCRateControl {
+ public:
+  RTCRateControlIAT();
+
+  ~RTCRateControlIAT();
+
+  void onNewRound(double round_len);
+  void onDataPacketReceived(const core::ContentObject &content_object,
+                            bool compute_stats);
+
+  auto shared_from_this() { return utils::shared_from(this); }
+
+ private:
+  void reset_congestion_statistics();
+
+  double compute_iat_stdev(std::vector<double> v);
+
+  CongestionCause apply_classification_tree(bool force_reply);
+
+ private:
+  uint32_t rounds_since_last_drop_;
+  uint32_t rounds_without_congestion_;
+  uint32_t rounds_with_congestion_;
+  double last_queue_;
+  uint64_t last_rcv_time_;
+  uint64_t last_prod_time_;
+  uint32_t last_seq_number_;
+  double target_rate_avg_;
+
+  // Iat values are not immediately added to the congestion free set of values
+  std::array<std::vector<double>, ROUND_HISTORY_SIZE> iat_on_hold_;
+  uint32_t round_index_;
+
+  // with congestion statistics
+  std::vector<double> iat_;
+  std::vector<double> received_rate_;
+  std::vector<double> target_rate_;
+
+  // congestion free statistics
+  std::vector<double> congestion_free_iat_;
+
+  CongestionCause congestion_cause_;
+};
+
+}  // end namespace rtc
+
+}  // end namespace protocol
+
+}  // end namespace transport