diff --git a/srt/PacketQueue.cpp b/srt/PacketQueue.cpp
index cb43bd13..87f078d6 100644
--- a/srt/PacketQueue.cpp
+++ b/srt/PacketQueue.cpp
@@ -9,6 +9,21 @@ static inline bool isSeqEdge(uint32_t seq, uint32_t cap) {
     return false;
 }
 
+static inline bool isSeqCycle(uint32_t first, uint32_t second) {
+    uint32_t diff;
+    if (first > second) {
+        diff = first - second;
+    } else {
+        diff = second - first;
+    }
+
+    if (diff > (MAX_SEQ >> 1)) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
 static inline bool isTSCycle(uint32_t first, uint32_t second) {
     uint32_t diff;
     if (first > second) {
@@ -220,4 +235,283 @@ std::string PacketQueue::dump() {
     return std::move(printer);
 }
 
+//////////////////// PacketRecvQueue //////////////////////////////////
+
+PacketRecvQueue::PacketRecvQueue(uint32_t max_size, uint32_t init_seq, uint32_t latency)
+    : _pkt_cap(max_size)
+    , _pkt_latency(latency)
+    , _pkt_expected_seq(init_seq)
+    , _pkt_buf(max_size) {}
+bool PacketRecvQueue::inputPacket(DataPacket::Ptr pkt, std::list<DataPacket::Ptr> &out) {
+    while (_size > 0 && _start == _end) {
+        if (_pkt_buf[_start]) {
+            out.push_back(_pkt_buf[_start]);
+            _size--;
+            _pkt_buf[_start] = nullptr;
+        }
+        _start = (_start + 1) % _pkt_cap;
+        _pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
+    }
+
+    tryInsertPkt(pkt);
+
+    DataPacket::Ptr it = _pkt_buf[_start];
+    while (it) {
+        out.push_back(it);
+        _size--;
+        _pkt_buf[_start] = nullptr;
+        _pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
+        _start = (_start + 1) % _pkt_cap;
+        it = _pkt_buf[_start];
+    }
+    while (timeLatency() > _pkt_latency) {
+        it = _pkt_buf[_start];
+        if (it) {
+            _pkt_buf[_start] = nullptr;
+            out.push_back(it);
+            _size--;
+        }
+        _pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
+        _start = (_start + 1) % _pkt_cap;
+    }
+    return true;
+}
+
+uint32_t PacketRecvQueue::timeLatency() {
+    if (_size <= 0) {
+        return 0;
+    }
+
+    auto first = getFirst()->timestamp;
+    auto last = getLast()->timestamp;
+
+    uint32_t dur;
+    if (last > first) {
+        dur = last - first;
+    } else {
+        dur = first - last;
+    }
+
+    if (dur > 0x80000000) {
+        dur = MAX_TS - dur;
+        WarnL << "cycle dur " << dur;
+    }
+
+    return dur;
+}
+std::list<PacketQueueInterface::LostPair> PacketRecvQueue::getLostSeq() {
+    std::list<PacketQueueInterface::LostPair> re;
+    if (_size <= 0) {
+        return re;
+    }
+
+    if (getExpectedSize() == getSize()) {
+        return re;
+    }
+
+    LostPair lost;
+    uint32_t steup = 0;
+    bool finish = true;
+
+    for (uint32_t i = _start; i != _end;) {
+        if (!_pkt_buf[i]) {
+            if (finish) {
+                finish = false;
+                lost.first = _pkt_expected_seq + steup;
+                lost.second = genExpectedSeq(lost.first + 1);
+            } else {
+                lost.second = genExpectedSeq(_pkt_expected_seq + steup + 1);
+            }
+        } else {
+            if (!finish) {
+                finish = true;
+                re.push_back(lost);
+            }
+        }
+        i = (i + 1) % _pkt_cap;
+        steup++;
+    }
+    return re;
+}
+
+size_t PacketRecvQueue::getSize() {
+    return _size;
+}
+size_t PacketRecvQueue::getExpectedSize() {
+    if (_size <= 0) {
+        return 0;
+    }
+
+    uint32_t max, min;
+    auto first = _pkt_expected_seq;
+    auto last = getLast()->packet_seq_number;
+    if (last >= first) {
+        max = last;
+        min = first;
+    } else {
+        max = first;
+        min = last;
+    }
+    if ((max - min) >= (MAX_SEQ >> 1)) {
+        TraceL << "cycle "
+               << "expected seq " << _pkt_expected_seq << " min " << min << " max " << max << " size " << _size;
+        return MAX_SEQ - _pkt_expected_seq + min + 1;
+    } else {
+        return max - _pkt_expected_seq + 1;
+    }
+}
+size_t PacketRecvQueue::getAvailableBufferSize() {
+    auto size = getExpectedSize();
+    if (_pkt_cap > size) {
+        return _pkt_cap - size;
+    }
+
+    if (_pkt_cap > _size) {
+        return _pkt_cap - _size;
+    }
+    WarnL << " cap " << _pkt_cap << " expected size " << size << " map size " << _size;
+    return _pkt_cap;
+}
+uint32_t PacketRecvQueue::getExpectedSeq() {
+    return _pkt_expected_seq;
+}
+
+std::string PacketRecvQueue::dump() {
+    _StrPrinter printer;
+    if (_size <= 0) {
+        printer << " expected seq :" << _pkt_expected_seq;
+    } else {
+        printer << " expected seq :" << _pkt_expected_seq << " size:" << _size
+                << " first:" << getFirst()->packet_seq_number;
+        printer << " last:" << getLast()->packet_seq_number;
+        printer << " latency:" << timeLatency() / 1e3;
+    }
+    return std::move(printer);
+}
+bool PacketRecvQueue::drop(uint32_t first, uint32_t last, std::list<DataPacket::Ptr> &out) {
+    uint32_t diff = 0;
+    if (isSeqCycle(_pkt_expected_seq, last)) {
+        if (last < _pkt_expected_seq) {
+            diff = MAX_SEQ - _pkt_expected_seq + last + 1;
+        } else {
+            WarnL << "drop first " << first << " last " << last << " expected " << _pkt_expected_seq;
+            return false;
+        }
+    } else {
+        if (last < _pkt_expected_seq) {
+            WarnL << "drop first " << first << " last " << last << " expected " << _pkt_expected_seq;
+            return false;
+        }
+        diff = last - _pkt_expected_seq + 1;
+    }
+
+    if (diff > getExpectedSize()) {
+        WarnL << " diff " << diff << " expected size " << getExpectedSize();
+        return false;
+    }
+
+    for (uint32_t i = 0; i < diff; i++) {
+        auto pos = (i + _start) % _pkt_cap;
+        if (_pkt_buf[pos]) {
+            out.push_back(_pkt_buf[pos]);
+            _pkt_buf[pos] = nullptr;
+            _size--;
+        }
+    }
+
+    _pkt_expected_seq = genExpectedSeq(last + 1);
+    _start = (diff + _start) % _pkt_cap;
+    if (_size <= 0) {
+        _end = _start;
+        WarnL;
+    }
+    return true;
+}
+
+void PacketRecvQueue::insertToCycleBuf(DataPacket::Ptr pkt, uint32_t diff) {
+    auto pos = (_start + diff) % _pkt_cap;
+
+    if (!_pkt_buf[pos]) {
+        _size++;
+    } else {
+        // WarnL << "repate packet " << pkt->packet_seq_number;
+        return;
+    }
+    _pkt_buf[pos] = pkt;
+    if (pos >= _end && (_start <= _end || pos < _start)) {
+        _end = (pos + 1) % _pkt_cap;
+    }
+}
+void PacketRecvQueue::tryInsertPkt(DataPacket::Ptr pkt) {
+    if (_pkt_expected_seq <= pkt->packet_seq_number) {
+        auto diff = pkt->packet_seq_number - _pkt_expected_seq;
+        if (diff >= (MAX_SEQ >> 1)) {
+            TraceL << "drop packet too later for cycle "
+                   << "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number;
+            return;
+        } else {
+            if (diff >= _pkt_cap) {
+                WarnL << "too new "
+                      << "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number << " cap "
+                      << _pkt_cap;
+                return;
+            }
+
+            insertToCycleBuf(pkt, diff);
+        }
+    } else {
+        auto diff = _pkt_expected_seq - pkt->packet_seq_number;
+        if (diff >= (MAX_SEQ >> 1)) {
+            diff = MAX_SEQ - diff;
+            if (diff >= _pkt_cap) {
+                WarnL << "too new "
+                      << "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number << " cap "
+                      << _pkt_cap;
+                return;
+            }
+
+            insertToCycleBuf(pkt, diff);
+
+            TraceL << " cycle packet "
+                   << "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number;
+        } else {
+            // TraceL << "drop packet too later "
+            //<< "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number;
+        }
+    }
+}
+DataPacket::Ptr PacketRecvQueue::getFirst() {
+    if (_size <= 0) {
+        return nullptr;
+    }
+
+    uint32_t i = _start;
+    while (1) {
+        if (_pkt_buf[i]) {
+            return _pkt_buf[i];
+        }
+        i = (i + 1) % _pkt_cap;
+    }
+}
+DataPacket::Ptr PacketRecvQueue::getLast() {
+    if (_size <= 0) {
+        return nullptr;
+    }
+    uint32_t steup = 1;
+    uint32_t i = (_end + _pkt_cap - steup) % _pkt_cap;
+    /*
+    while (1) {
+        if (_pkt_buf[i]) {
+            _end = (i + 1) % _pkt_cap;
+            return _pkt_buf[i];
+        }
+        i = (_end + _pkt_cap - steup) % _pkt_cap;
+        steup++;
+    }
+    */
+    if (!_pkt_buf[i]) {
+        WarnL << "start " << _start << " end" << _end << " size " << _size;
+    }
+    return _pkt_buf[i];
+}
 } // namespace SRT
\ No newline at end of file
diff --git a/srt/PacketQueue.hpp b/srt/PacketQueue.hpp
index 58d5f18a..d3e224c6 100644
--- a/srt/PacketQueue.hpp
+++ b/srt/PacketQueue.hpp
@@ -7,14 +7,34 @@
 #include <memory>
 #include <tuple>
 #include <utility>
+#include <vector>
 
 namespace SRT {
 
+class PacketQueueInterface {
+public:
+    using Ptr = std::shared_ptr<PacketQueueInterface>;
+    using LostPair = std::pair<uint32_t, uint32_t>;
+
+    PacketQueueInterface() = default;
+    virtual ~PacketQueueInterface() = default;
+    virtual bool inputPacket(DataPacket::Ptr pkt, std::list<DataPacket::Ptr> &out) = 0;
+
+    virtual uint32_t timeLatency() = 0;
+    virtual std::list<LostPair> getLostSeq() = 0;
+
+    virtual size_t getSize() = 0;
+    virtual size_t getExpectedSize() = 0;
+    virtual size_t getAvailableBufferSize() = 0;
+    virtual uint32_t getExpectedSeq() = 0;
+
+    virtual std::string dump() = 0;
+    virtual bool drop(uint32_t first, uint32_t last, std::list<DataPacket::Ptr> &out) = 0;
+};
 // for recv
-class PacketQueue {
+class PacketQueue : public PacketQueueInterface {
 public:
     using Ptr = std::shared_ptr<PacketQueue>;
-    using LostPair = std::pair<uint32_t, uint32_t>;
 
     PacketQueue(uint32_t max_size, uint32_t init_seq, uint32_t latency);
     ~PacketQueue() = default;
@@ -37,10 +57,46 @@ private:
 private:
     uint32_t _pkt_cap;
     uint32_t _pkt_latency;
-    uint32_t _pkt_expected_seq = 0;
+    uint32_t _pkt_expected_seq;
     std::map<uint32_t, DataPacket::Ptr> _pkt_map;
 };
 
+class PacketRecvQueue : public PacketQueueInterface {
+public:
+    using Ptr = std::shared_ptr<PacketRecvQueue>;
+
+    PacketRecvQueue(uint32_t max_size, uint32_t init_seq, uint32_t latency);
+    ~PacketRecvQueue() = default;
+    bool inputPacket(DataPacket::Ptr pkt, std::list<DataPacket::Ptr> &out);
+
+    uint32_t timeLatency();
+    std::list<LostPair> getLostSeq();
+
+    size_t getSize();
+    size_t getExpectedSize();
+    size_t getAvailableBufferSize();
+    uint32_t getExpectedSeq();
+
+    std::string dump();
+    bool drop(uint32_t first, uint32_t last, std::list<DataPacket::Ptr> &out);
+
+private:
+    void tryInsertPkt(DataPacket::Ptr pkt);
+    void insertToCycleBuf(DataPacket::Ptr pkt, uint32_t diff);
+    DataPacket::Ptr getFirst();
+    DataPacket::Ptr getLast();
+
+private:
+    uint32_t _pkt_cap;
+    uint32_t _pkt_latency;
+    uint32_t _pkt_expected_seq;
+
+    std::vector<DataPacket::Ptr> _pkt_buf;
+    uint32_t _start = 0;
+    uint32_t _end = 0;
+    size_t _size = 0;
+};
+
 } // namespace SRT
 
 #endif // ZLMEDIAKIT_SRT_PACKET_QUEUE_H
\ No newline at end of file
diff --git a/srt/SrtTransport.cpp b/srt/SrtTransport.cpp
index 8089c168..ba90b8ab 100644
--- a/srt/SrtTransport.cpp
+++ b/srt/SrtTransport.cpp
@@ -213,7 +213,7 @@ void SrtTransport::handleHandshakeConclusion(HandshakePacket &pkt, struct sockad
         sendControlPacket(res, true);
         TraceL << " buf size = " << res->max_flow_window_size << " init seq =" << _init_seq_number
                << " latency=" << delay;
-        _recv_buf = std::make_shared<PacketQueue>(getPktBufSize(), _init_seq_number, delay * 1e3);
+        _recv_buf = std::make_shared<PacketRecvQueue>(getPktBufSize(), _init_seq_number, delay * 1e3);
         _send_buf = std::make_shared<PacketSendQueue>(getPktBufSize(), delay * 1e3);
         _send_packet_seq_number = _init_seq_number;
         _buf_delay = delay;
diff --git a/srt/SrtTransport.hpp b/srt/SrtTransport.hpp
index eb7180fc..2fbd8064 100644
--- a/srt/SrtTransport.hpp
+++ b/srt/SrtTransport.hpp
@@ -120,7 +120,7 @@ private:
 
     PacketSendQueue::Ptr _send_buf;
     uint32_t _buf_delay = 120;
-    PacketQueue::Ptr _recv_buf;
+    PacketQueueInterface::Ptr _recv_buf;
     // NackContext _recv_nack;
     uint32_t _rtt = 100 * 1000;
     uint32_t _rtt_variance = 50 * 1000;