diff --git a/components/free_rtos/ethernet/eth_tx_flow.cpp b/components/free_rtos/ethernet/eth_tx_flow.cpp
index 9e178a8..3f5ee14 100644
--- a/components/free_rtos/ethernet/eth_tx_flow.cpp
+++ b/components/free_rtos/ethernet/eth_tx_flow.cpp
@@ -32,7 +32,7 @@ static void eth_initTxFreePktQ(void * appPriv, EnetDma_PktQ * p_packet_queue)
     uint32_t i;
 
     /// ������������ ���������� �������
-    int i_max = ENET_SYSCFG_TOTAL_NUM_TX_PKT;
+    int i_max = (ENET_SYSCFG_TOTAL_NUM_TX_PKT);
 
     /* Initialize TX EthPkts and queue them to txFreePktInfoQ */
     for (i = 0U; i < i_max; i++)
@@ -125,7 +125,7 @@ bool free_rtos::EthTxFlow::open(uint32_t id, int32_t enetDmaTxChId)
     dma_handle_ = txChInfo.hTxCh;
 
     EnetAppUtils_assert(txChInfo.useGlobalEvt == true);
-    EnetAppUtils_assert(txChInfo.maxNumTxPkts >= ENET_SYSCFG_TOTAL_NUM_TX_PKT);
+    EnetAppUtils_assert(txChInfo.maxNumTxPkts >= (ENET_SYSCFG_TOTAL_NUM_TX_PKT));
 
     if (dma_handle_ == nullptr)
     {
@@ -173,16 +173,12 @@ bool free_rtos::EthTxFlow::send(TEthMacPorts port_id, uint8_t * p_data, uint32_t
     EnetDma_Pkt *txPktInfo;
     int32_t status;
 
-    /*
-     * ������������ ��������� ������ � �������� enet � ������ �� � ������� ��������� ������� txFreePktInfoQ
-     */
-    eth_retrieveFreeTxPkts(&dma_handle_, &tx_free_pktq_);
-
-    /// �������������� ���� txSubmitQ
     EnetQueue_initQ(&txSubmitQ);
 
-    /* ������� �� ������� ���� ��������� ����� TX Eth */
+    eth_retrieveFreeTxPkts(&dma_handle_, &tx_free_pktq_);
+
     txPktInfo = (EnetDma_Pkt *)EnetQueue_deq(&tx_free_pktq_);
+
     if (txPktInfo != NULL)
     {
         ///�������� ������ ������ � �����
@@ -227,10 +223,12 @@ bool free_rtos::EthTxFlow::send(TEthMacPorts port_id, uint8_t * p_data, uint32_t
 bool free_rtos::EthTxFlow::send(TxFlowHandlerArgs& handlerArgs, uint32_t numScatterSegments)
 {
     if (handlerArgs.port_id >= e_ethMacTotal) {
+        EnetAppUtils_print("Wrong port id\r\n");
+
         return false;
     }
 
-    if (!port_data_[handlerArgs.port_id].tx_enable) {
+    if (port_data_[handlerArgs.port_id].tx_enable == false) {
         return false;
     }
 
@@ -238,24 +236,25 @@ bool free_rtos::EthTxFlow::send(TxFlowHandlerArgs& handlerArgs, uint32_t numScat
     EnetDma_Pkt *txPktInfo;
     int32_t status;
 
-    eth_retrieveFreeTxPkts(&dma_handle_, &tx_free_pktq_);
-
     EnetQueue_initQ(&txSubmitQ);
 
+    eth_retrieveFreeTxPkts(&dma_handle_, &tx_free_pktq_);
+
     txPktInfo = (EnetDma_Pkt *)EnetQueue_deq(&tx_free_pktq_);
+
     if (txPktInfo != NULL)
     {
         for(size_t scatter_segment = 0; scatter_segment < numScatterSegments; scatter_segment++)
         {
             handlerArgs.buffer = txPktInfo->sgList.list[scatter_segment].bufPtr;
-            txPktInfo->sgList.list[scatter_segment].segmentFilledLen = handlerArgs.stack_handler->Sender(handlerArgs, scatter_segment);
+            txPktInfo->sgList.list[scatter_segment].segmentFilledLen = handlerArgs.stack_handler->Sender(handlerArgs, 0);
         }
 
-        txPktInfo->sgList.numScatterSegments = numScatterSegments;
+        txPktInfo->sgList.numScatterSegments = 1;
         txPktInfo->chkSumInfo = 0U;
         txPktInfo->appPriv = nullptr;
         txPktInfo->tsInfo.txPktSeqId = 0;
-        txPktInfo->txPktTc = 0; /// Traffic class ����� ��� IPv6
+        txPktInfo->txPktTc = 0; /// Traffic class IPv6
         txPktInfo->tsInfo.enableHostTxTs = false;
         txPktInfo->txPortNum = (Enet_MacPort)handlerArgs.port_id;
 
diff --git a/components/free_rtos/ethernet_industry/eth_ecat.cpp b/components/free_rtos/ethernet_industry/eth_ecat.cpp
index bc856f0..f84e37e 100644
--- a/components/free_rtos/ethernet_industry/eth_ecat.cpp
+++ b/components/free_rtos/ethernet_industry/eth_ecat.cpp
@@ -20,7 +20,7 @@ EthEcat::EthEcat(Eth& eth)
 
 void EthEcat::Init(TEthMacPorts port_id, uint32_t period_microsec = 250) {
     port_id_ = port_id;
-    telegram_.init(port_id, period_microsec, 6);
+    telegram_.init(port_id, period_microsec, 4);
 
     Timer::Settings ecat_tmr_sett = {
                  .input_clk_Hz = 25000000, // 25MHz
diff --git a/components/free_rtos/ethernet_industry/eth_ecat_telegram.cpp b/components/free_rtos/ethernet_industry/eth_ecat_telegram.cpp
index 56393e8..3ebc508 100644
--- a/components/free_rtos/ethernet_industry/eth_ecat_telegram.cpp
+++ b/components/free_rtos/ethernet_industry/eth_ecat_telegram.cpp
@@ -51,7 +51,7 @@ int32_t EcatTelegram::Process(uint8_t *p_data, uint32_t len) {
     return 0;
 }
 
-uint32_t EcatTelegram::Sender(HandlerArgs& handlerArgs, size_t scatter_segment) {
+uint16_t EcatTelegram::Sender(HandlerArgs& handlerArgs, size_t scatter_segment) {
     uint8_t *raw = pack(handlerArgs.buffer);
 
     //DebugP_log((char*)"Sender started\r\n");
@@ -118,6 +118,7 @@ bool EcatTelegram::transfer() {
 
     txFlowHandlerArgs.port_id = port_id_;
     txFlowHandlerArgs.stack_handler = this;
+    txFlowHandlerArgs.buffer = nullptr;
 
     while(1) {
         tick_counter_start = ecat_timer_.Wait();
diff --git a/components/free_rtos/ethernet_industry/eth_ecat_telegram.hpp b/components/free_rtos/ethernet_industry/eth_ecat_telegram.hpp
index b09814c..90df664 100644
--- a/components/free_rtos/ethernet_industry/eth_ecat_telegram.hpp
+++ b/components/free_rtos/ethernet_industry/eth_ecat_telegram.hpp
@@ -66,7 +66,7 @@ public:
     }
 
     virtual int32_t Process(uint8_t *p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 
     void init(TEthMacPorts port_id, uint32_t period_microsec, uint32_t max_transfer_attempts) {
         port_id_ = port_id;
diff --git a/components/free_rtos/ethernet_ip/eth_arp.cpp b/components/free_rtos/ethernet_ip/eth_arp.cpp
index 7db6303..bd52d68 100644
--- a/components/free_rtos/ethernet_ip/eth_arp.cpp
+++ b/components/free_rtos/ethernet_ip/eth_arp.cpp
@@ -205,7 +205,7 @@ int32_t free_rtos::EthArp::Process(uint8_t * p_data, uint32_t len)
     return 0;
 }
 
-uint32_t free_rtos::EthArp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
+uint16_t free_rtos::EthArp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
 {
     return 0;
 }
diff --git a/components/free_rtos/ethernet_ip/eth_arp.hpp b/components/free_rtos/ethernet_ip/eth_arp.hpp
index 1d90351..6238020 100644
--- a/components/free_rtos/ethernet_ip/eth_arp.hpp
+++ b/components/free_rtos/ethernet_ip/eth_arp.hpp
@@ -32,7 +32,7 @@ public:
     bool try_request(uint32_t ip);
 
     virtual int32_t Process(uint8_t * p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 private:
     bool request(uint32_t ip);
 
diff --git a/components/free_rtos/ethernet_ip/eth_checksum.c b/components/free_rtos/ethernet_ip/eth_checksum.c
index 5b74278..7be35a7 100644
--- a/components/free_rtos/ethernet_ip/eth_checksum.c
+++ b/components/free_rtos/ethernet_ip/eth_checksum.c
@@ -25,3 +25,30 @@ uint16_t eth_calcChksum(uint32_t sum, uint8_t * const data, uint16_t len)
 
     return ~sum;
 }
+
+uint16_t eth_calcChksum2(uint32_t sum, uint8_t * const hdata, uint16_t hlen, uint8_t * const data, uint16_t len)
+{
+    uint16_t i;
+    uint16_t hsize = hlen - 1;
+    uint16_t size = len - 1;
+
+    if ( (hlen == 0) || (len == 0) )
+      return 0;
+
+    for ( i = 0; i < hsize; i+=2 )
+      sum += ((uint16_t)hdata[i] << 8) + hdata[i+1];
+
+    if (hlen & 0x01)
+      sum += (uint16_t)hdata[i] << 8;
+
+    for ( i = 0; i < size; i+=2 )
+      sum += ((uint16_t)data[i] << 8) + data[i+1];
+
+    if (len & 0x01)
+      sum += (uint16_t)data[i] << 8;
+
+    while ( sum >> 16 )
+      sum = (sum & 0xFFFF) + (sum >> 16);
+
+    return ~sum;
+}
diff --git a/components/free_rtos/ethernet_ip/eth_checksum.h b/components/free_rtos/ethernet_ip/eth_checksum.h
index f1887bb..869e2ca 100644
--- a/components/free_rtos/ethernet_ip/eth_checksum.h
+++ b/components/free_rtos/ethernet_ip/eth_checksum.h
@@ -15,6 +15,7 @@ extern "C" {
 #endif
 
 uint16_t eth_calcChksum(uint32_t sum, uint8_t * const data, uint16_t len);
+uint16_t eth_calcChksum2(uint32_t sum, uint8_t * const hdata, uint16_t hlen, uint8_t * const data, uint16_t len);
 
 #ifdef __cplusplus
 }
diff --git a/components/free_rtos/ethernet_ip/eth_icmp.cpp b/components/free_rtos/ethernet_ip/eth_icmp.cpp
index 4b5b7ef..82adc79 100644
--- a/components/free_rtos/ethernet_ip/eth_icmp.cpp
+++ b/components/free_rtos/ethernet_ip/eth_icmp.cpp
@@ -40,7 +40,7 @@ int32_t free_rtos::EthIcmp::Process(uint8_t * p_data, uint32_t len)
     return len;
 }
 
-uint32_t free_rtos::EthIcmp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
+uint16_t free_rtos::EthIcmp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
 {
     return 0;
 }
diff --git a/components/free_rtos/ethernet_ip/eth_icmp.hpp b/components/free_rtos/ethernet_ip/eth_icmp.hpp
index bf85444..17d112f 100644
--- a/components/free_rtos/ethernet_ip/eth_icmp.hpp
+++ b/components/free_rtos/ethernet_ip/eth_icmp.hpp
@@ -18,7 +18,7 @@ namespace free_rtos {
 class EthIcmp : public Handler {
 public:
     virtual int32_t Process(uint8_t * p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 
     uint32_t getStat() {return rx_cnt_;};
 private:
diff --git a/components/free_rtos/ethernet_ip/eth_ip.cpp b/components/free_rtos/ethernet_ip/eth_ip.cpp
index 464f0c8..7ff5757 100644
--- a/components/free_rtos/ethernet_ip/eth_ip.cpp
+++ b/components/free_rtos/ethernet_ip/eth_ip.cpp
@@ -89,14 +89,44 @@ bool free_rtos::EthIp::send(TEthMacPorts port_id, uint32_t dest_ip, uint8_t prot
     return eth_stack_.send_pkt(port_id, mac_dst, ETH_PROT_IP_BE, pkt);
 }
 
+inline uint16_t free_rtos::EthIp::fillIpHeader(IpHandlerArgs& ipHandlerArgs)
+{
+    static_assert(sizeof(TIpHeader) == (IP_HEADER_WORD_SIZE * 4), "Ip header size doesn't match version !");
+
+    uint16_t ip_len = sizeof(TIpHeader) + ipHandlerArgs.ip_header_len + ipHandlerArgs.ip_data_len;
+    uint16_t cksum = 0;
+
+    memcpy(ipHandlerArgs.ip_header.ip_src, &self_ip_, ETH_IP_ADDR_LEN);
+    memcpy(ipHandlerArgs.ip_header.ip_dst, &ipHandlerArgs.dest_ip, ETH_IP_ADDR_LEN);
+
+    ipHandlerArgs.ip_header.ip_hl_v = (IP_VER << 4) | IP_HEADER_WORD_SIZE;
+    ipHandlerArgs.ip_header.ip_tos = 0;
+    ipHandlerArgs.ip_header.ip_len = BASE_SWAP16(ip_len);
+    ipHandlerArgs.ip_header.ip_id = BASE_SWAP16(ip_indet_);
+    ipHandlerArgs.ip_header.ip_off = 0;
+    ipHandlerArgs.ip_header.ip_ttl = IP_TIME_TO_LIVE;
+    ipHandlerArgs.ip_header.ip_p = ipHandlerArgs.ip_prot_id;
+    ipHandlerArgs.ip_header.ip_sum = 0;
+
+    cksum = eth_calcChksum(0, (uint8_t *)&ipHandlerArgs.ip_header, sizeof(TIpHeader));
+
+    ipHandlerArgs.ip_header.ip_sum = BASE_SWAP16(cksum);
+
+    ++ip_indet_;
+
+    return sizeof(TIpHeader);
+}
+
 bool free_rtos::EthIp::send(IpHandlerArgs& handlerArgs)
 {
     handlerArgs.stack_handler = this;
 
+    fillIpHeader(handlerArgs);
+
     return eth_stack_.send_pkt(handlerArgs);
 }
 
-inline uint32_t free_rtos::EthIp::fillEthFrameHeader(IpHandlerArgs& ipHandlerArgs)
+inline uint16_t free_rtos::EthIp::fillEthFrameHeader(IpHandlerArgs& ipHandlerArgs)
 {
     TEthFrameHeader * p_eth_hdr = (TEthFrameHeader *)ipHandlerArgs.buffer;
     uint64_t mac_dst;
@@ -105,7 +135,7 @@ inline uint32_t free_rtos::EthIp::fillEthFrameHeader(IpHandlerArgs& ipHandlerArg
         return 0;
     }
 
-    p_eth_hdr->prot_id = ipHandlerArgs.ip_prot_id;
+    p_eth_hdr->prot_id = ETH_PROT_IP_BE;
 
     memcpy(p_eth_hdr->mac_src, &self_mac_, ETH_FRAME_MAC_ADDR_LEN_BYTES);
     memcpy(p_eth_hdr->mac_dest, &mac_dst, ETH_FRAME_MAC_ADDR_LEN_BYTES);
@@ -113,46 +143,20 @@ inline uint32_t free_rtos::EthIp::fillEthFrameHeader(IpHandlerArgs& ipHandlerArg
     return sizeof(TEthFrameHeader);
 }
 
-inline uint32_t free_rtos::EthIp::fillIpHeader(IpHandlerArgs& ipHandlerArgs, uint32_t ip_len)
+uint16_t free_rtos::EthIp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
 {
-    TIpHeader * ip_header = (TIpHeader *)(ipHandlerArgs.buffer + sizeof(TEthFrameHeader));
-    uint16_t cksum = 0;
-
-    memcpy(ip_header->ip_src, &self_ip_, ETH_IP_ADDR_LEN);
-    memcpy(ip_header->ip_dst, &ipHandlerArgs.dest_ip, ETH_IP_ADDR_LEN);
-
-    ip_header->ip_hl_v = (IP_VER << 4) | IP_HEADER_WORD_SIZE;
-    ip_header->ip_tos = 0;
-    ip_header->ip_len = BASE_SWAP16(ip_len);
-    ip_header->ip_id = BASE_SWAP16(ip_indet_);
-    ip_header->ip_off = 0;
-    ip_header->ip_ttl = IP_TIME_TO_LIVE;
-    ip_header->ip_p = ipHandlerArgs.ip_prot_id;
-    ip_header->ip_sum = 0;
-
-    cksum = eth_calcChksum(0, (uint8_t *)ip_header, sizeof(TIpHeader));
-
-    ip_header->ip_sum = BASE_SWAP16(cksum);
-
-    ++ip_indet_;
-
-    return sizeof(TIpHeader);
-}
-
-uint32_t free_rtos::EthIp::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
-{
-    static_assert(sizeof(TIpHeader) == (IP_HEADER_WORD_SIZE * 4), "Ip header size doesn't match version !");
-
     IpHandlerArgs& ipHandlerArgs = static_cast<IpHandlerArgs&>(handlerArgs); // downcasting back to derived type
-    uint32_t ip_len = ipHandlerArgs.ip_handler->Sender(ipHandlerArgs, scatter_segment);
 
     if(fillEthFrameHeader(ipHandlerArgs) == 0) {
-        return 0;
+        //EnetAppUtils_print("Cannot find destination mac\r\n");
     }
 
-    fillIpHeader(ipHandlerArgs, ip_len);
+    TIpHeader * ip_header = (TIpHeader *)(ipHandlerArgs.buffer + sizeof(TEthFrameHeader));
+    *ip_header = ipHandlerArgs.ip_header;
 
-    return sizeof(TEthFrameHeader) + sizeof(TIpHeader) + ip_len;
+    ipHandlerArgs.ip_handler->Sender(ipHandlerArgs, scatter_segment);
+
+    return sizeof(TEthFrameHeader) + sizeof(TIpHeader) + ipHandlerArgs.ip_header_len + ipHandlerArgs.ip_data_len;
 }
 
 int32_t free_rtos::EthIp::Process(uint8_t * p_data, uint32_t len)
diff --git a/components/free_rtos/ethernet_ip/eth_ip.hpp b/components/free_rtos/ethernet_ip/eth_ip.hpp
index 2ca7983..f5d6d3f 100644
--- a/components/free_rtos/ethernet_ip/eth_ip.hpp
+++ b/components/free_rtos/ethernet_ip/eth_ip.hpp
@@ -33,7 +33,7 @@ public:
     virtual bool send(IpHandlerArgs& handlerArgs) override;
 
     virtual int32_t Process(uint8_t * p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 
     bool Register(uint8_t prot_id, Handler * p_handler);
 
@@ -48,8 +48,8 @@ private:
 
     uint16_t ip_indet_; /// \u043f\u0457\u0405\u043f\u0457\u0405\u043f\u0457\u0405\u043f\u0457\u0405 ip_id
 
-    inline uint32_t fillEthFrameHeader(IpHandlerArgs& ipHandlerArgs);
-    inline uint32_t fillIpHeader(IpHandlerArgs& ipHandlerArgs, uint32_t ip_len);
+    inline uint16_t fillIpHeader(IpHandlerArgs& handlerArgs);
+    inline uint16_t fillEthFrameHeader(IpHandlerArgs& ipHandlerArgs);
 };
 
 }
diff --git a/components/free_rtos/ethernet_ip/eth_ip_iface.hpp b/components/free_rtos/ethernet_ip/eth_ip_iface.hpp
index 9ab2834..972df2e 100644
--- a/components/free_rtos/ethernet_ip/eth_ip_iface.hpp
+++ b/components/free_rtos/ethernet_ip/eth_ip_iface.hpp
@@ -11,12 +11,16 @@
 #include <cstdint>
 #include "free_rtos/ethernet/eth_types.h"
 #include "free_rtos/ethernet/eth_frame.h"
+#include "free_rtos/ethernet_ip/eth_ip_types.h"
 #include "free_rtos/ethernet_ip/eth_stack_iface.hpp"
 
 struct IpHandlerArgs : public EthStackHandlerArgs {
+    uint16_t ip_header_len;
+    uint16_t ip_data_len;
     uint32_t dest_ip;
     uint8_t ip_prot_id;
     Handler* ip_handler;
+    TIpHeader ip_header;
 };
 
 class EthIpIface {
diff --git a/components/free_rtos/ethernet_ip/eth_stack.cpp b/components/free_rtos/ethernet_ip/eth_stack.cpp
index f8a9fed..b2ef6eb 100644
--- a/components/free_rtos/ethernet_ip/eth_stack.cpp
+++ b/components/free_rtos/ethernet_ip/eth_stack.cpp
@@ -66,7 +66,7 @@ bool free_rtos::EthStack::send_pkt(TEthMacPorts port_id, uint64_t mac_dst, uint1
 
 bool free_rtos::EthStack::send_pkt(EthStackHandlerArgs& handlerArgs)
 {
-    handlerArgs.port_id = eth_.mac_port_; // overwriting
+    //handlerArgs.port_id = eth_.mac_port_; // overwriting
 
     return tx_flow_.send(handlerArgs, 1);
 }
diff --git a/components/free_rtos/ethernet_ip/eth_udp_client.cpp b/components/free_rtos/ethernet_ip/eth_udp_client.cpp
index 45e466e..cf5a043 100644
--- a/components/free_rtos/ethernet_ip/eth_udp_client.cpp
+++ b/components/free_rtos/ethernet_ip/eth_udp_client.cpp
@@ -6,7 +6,6 @@
  */
 #include "free_rtos/ethernet_ip/eth_udp_client.hpp"
 #include "free_rtos/base/swap.h"
-#include "free_rtos/ethernet_ip/eth_udp_types.h"
 #include "free_rtos/ethernet_ip/eth_ip_types.h"
 #include "free_rtos/ethernet_ip/eth_checksum.h"
 #include "free_rtos/ethernet_ip/eth_ip_prots_id.h"
@@ -50,10 +49,10 @@ void free_rtos::EthUpdClient::put_data(uint8_t * p_data, uint32_t len)
     rx_sem_.post();
 }
 
-int32_t free_rtos::EthUpdClient::get_data(uint8_t * p_data, uint32_t len)
+size_t free_rtos::EthUpdClient::get_data(uint8_t * p_data, uint32_t len)
 {
     std::vector<uint8_t>& buff = buff_[out_toggle_];
-    uint32_t size = buff.size();
+    size_t size = buff.size();
 
     if (size > len) {
         size = len;
@@ -74,23 +73,25 @@ bool free_rtos::EthUpdClient::capture_buffer()
     UDPToggle expected = static_cast<UDPToggle>((desired + 1)%UDPToggle::UDP_BUF_NUM);
 
     if(in_toggle_.compare_exchange_weak(expected, desired) == false) {
-        return true;
+        return false;
     }
 
     out_toggle_ = expected;
 
-    return buff_[expected].empty();
+    return true;
 }
 
 size_t free_rtos::EthUpdClient::get_data_size()
 {
-    if (buff_[out_toggle_].empty() == true) {
-        if(capture_buffer() == true) {
-            return 0;
+    size_t size = buff_[out_toggle_].size();
+
+    if (size == 0) {
+        if(capture_buffer() != false) {
+            size = buff_[out_toggle_].size();
         }
     }
 
-    return buff_[out_toggle_].size();
+    return size;
 }
 
 int32_t free_rtos::EthUpdClient::read(uint8_t * p_data, uint32_t len)
@@ -99,8 +100,8 @@ int32_t free_rtos::EthUpdClient::read(uint8_t * p_data, uint32_t len)
         return 0;
     }
 
-    if(buff_[out_toggle_].empty() == true) {
-        while (capture_buffer() == true) {
+    if(buff_[out_toggle_].size() == 0) {
+        while (capture_buffer() == false) {
             rx_sem_.pend();
         }
     }
@@ -114,8 +115,8 @@ int32_t free_rtos::EthUpdClient::read_async(uint8_t * p_data, uint32_t len)
         return 0;
     }
 
-    if (buff_[out_toggle_].empty() == true) {
-        if(capture_buffer() == true) {
+    if (buff_[out_toggle_].size() == 0) {
+        if(capture_buffer() == false) {
             return 0;
         }
     }
@@ -126,7 +127,14 @@ int32_t free_rtos::EthUpdClient::read_async(uint8_t * p_data, uint32_t len)
 void free_rtos::EthUpdClient::clear()
 {
     buff_[out_toggle_].clear();
+
+    while (capture_buffer() == false) {
+        rx_sem_.pend();
+    }
+
+    buff_[out_toggle_].clear();
 }
+
 /*
 bool free_rtos::EthUpdClient::write(uint32_t ip_dst_be, uint8_t * p_data, uint32_t len)
 {
@@ -169,42 +177,18 @@ bool free_rtos::EthUpdClient::write(uint32_t ip_dst_be, uint8_t * p_data, uint32
     return ip_iface_.send(port_id_, ip_dst_be, IP_PROT_UDP, eth_pkt_);
 }
 */
-bool free_rtos::EthUpdClient::write(uint32_t ip_dst_be, uint8_t * p_data, uint32_t len)
-{
-    UDPHandlerArgs udpHandlerArgs;
 
-    udpHandlerArgs.port_id = port_id_;
-    udpHandlerArgs.dest_ip = ip_dst_be;
-    udpHandlerArgs.ip_prot_id = IP_PROT_UDP;
-    udpHandlerArgs.ip_handler = this;
-    udpHandlerArgs.p_data = p_data;
-    udpHandlerArgs.len = len;
+uint16_t free_rtos::EthUpdClient::fill_udp_header(UDPHandlerArgs& udpHandlerArgs) {
+    uint16_t udp_len = udpHandlerArgs.ip_header_len + udpHandlerArgs.ip_data_len;
 
-    return ip_iface_.send(udpHandlerArgs);
-}
-
-uint32_t free_rtos::EthUpdClient::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
-{
-    UDPHandlerArgs& udpHandlerArgs = static_cast<UDPHandlerArgs&>(handlerArgs);  // downcasting back to derived type
-    TUdpHeader * hdr = (TUdpHeader *)(udpHandlerArgs.buffer + sizeof(TEthFrameHeader) + sizeof(TIpHeader));
-    uint8_t * p_udp_data = (uint8_t *)(udpHandlerArgs.buffer + sizeof(TEthFrameHeader) + sizeof(TIpHeader) + sizeof(TUdpHeader));
-    uint32_t udp_len = udpHandlerArgs.len + sizeof(TUdpHeader);
-
-    if (udpHandlerArgs.dest_ip == 0) {
-        udpHandlerArgs.dest_ip = src_ip_;
-    }
-
-    hdr->Src_port = port_src_be_;
-    hdr->Dst_port = port_dst_be_;
-    hdr->Length = BASE_SWAP16(udp_len);
-    hdr->Chk_sum = 0;
-
-    memcpy(p_udp_data, udpHandlerArgs.p_data, udpHandlerArgs.len);
+    udpHandlerArgs.udp_header.Src_port = port_src_be_;
+    udpHandlerArgs.udp_header.Dst_port = port_dst_be_;
+    udpHandlerArgs.udp_header.Length = BASE_SWAP16(udp_len);
+    udpHandlerArgs.udp_header.Chk_sum = 0;
 
     if (use_checksum_) {
         uint32_t self_ip = ip_iface_.getSelfIpAddr();
         uint32_t chk_sum32 = 0;
-
         uint8_t * const dst_ip = (uint8_t *)&udpHandlerArgs.dest_ip;
         uint8_t * const src_ip = (uint8_t *)&self_ip;
 
@@ -216,12 +200,47 @@ uint32_t free_rtos::EthUpdClient::Sender(HandlerArgs& handlerArgs, size_t scatte
 
         chk_sum32 += IP_PROT_UDP + udp_len;
 
-        uint16_t chk_sum16 = eth_calcChksum(chk_sum32, (uint8_t *)hdr, udp_len);
+        uint16_t chk_sum16 = eth_calcChksum2(chk_sum32, (uint8_t *)&udpHandlerArgs.udp_header, sizeof(TUdpHeader), (uint8_t *)udpHandlerArgs.p_data, udpHandlerArgs.ip_data_len);
 
-        hdr->Chk_sum = BASE_SWAP16(chk_sum16);
+        udpHandlerArgs.udp_header.Chk_sum = BASE_SWAP16(chk_sum16);
     }
 
-    return udp_len;
+    return sizeof(TUdpHeader);
+}
+
+bool free_rtos::EthUpdClient::write(uint32_t ip_dst_be, uint8_t * p_data, uint32_t len)
+{
+    UDPHandlerArgs udpHandlerArgs;
+
+    if (ip_dst_be == 0) {
+        ip_dst_be = src_ip_;
+    }
+
+    //udpHandlerArgs.buffer = nullptr;
+    udpHandlerArgs.port_id = port_id_;
+    //udpHandlerArgs.stack_handler = nullptr;
+    udpHandlerArgs.ip_header_len = sizeof(TUdpHeader);
+    udpHandlerArgs.ip_data_len = len;
+    udpHandlerArgs.dest_ip = ip_dst_be;
+    udpHandlerArgs.ip_prot_id = IP_PROT_UDP;
+    udpHandlerArgs.ip_handler = this;
+    udpHandlerArgs.p_data = p_data;
+
+    fill_udp_header(udpHandlerArgs);
+
+    return ip_iface_.send(udpHandlerArgs);
+}
+
+uint16_t free_rtos::EthUpdClient::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
+{
+    UDPHandlerArgs& udpHandlerArgs = static_cast<UDPHandlerArgs&>(handlerArgs);  // downcasting back to derived type
+    TUdpHeader * hdr = (TUdpHeader *)(udpHandlerArgs.buffer + sizeof(TEthFrameHeader) + sizeof(TIpHeader));
+    uint8_t * p_udp_data = (uint8_t *)(udpHandlerArgs.buffer + sizeof(TEthFrameHeader) + sizeof(TIpHeader) + sizeof(TUdpHeader));
+
+    *hdr = udpHandlerArgs.udp_header;
+    memcpy(p_udp_data, udpHandlerArgs.p_data, udpHandlerArgs.ip_data_len);
+
+    return udpHandlerArgs.ip_header_len + udpHandlerArgs.ip_data_len;
 }
 
 int32_t free_rtos::EthUpdClient::Process(uint8_t * p_data, uint32_t len)
diff --git a/components/free_rtos/ethernet_ip/eth_udp_client.hpp b/components/free_rtos/ethernet_ip/eth_udp_client.hpp
index e802316..721438d 100644
--- a/components/free_rtos/ethernet_ip/eth_udp_client.hpp
+++ b/components/free_rtos/ethernet_ip/eth_udp_client.hpp
@@ -21,13 +21,14 @@
 #include "free_rtos/ethernet/eth_frame.h"
 #include "free_rtos/ethernet_ip/eth_ip_iface.hpp"
 #include "free_rtos/ethernet/eth_types.h"
+#include "free_rtos/ethernet_ip/eth_udp_types.h"
 #include "free_rtos/handler_store/handler_store.hpp"
 
 namespace free_rtos {
 
 struct UDPHandlerArgs : public IpHandlerArgs {
     void * p_data;
-    uint32_t len;
+    TUdpHeader udp_header;
 };
 
 enum UDPToggle : uint32_t {
@@ -46,9 +47,8 @@ public:
                  bool use_chksum);
 
     virtual int32_t Process(uint8_t * p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 
-    bool capture_buffer();
     size_t get_data_size();
 
     int32_t read(uint8_t * p_data, uint32_t len);
@@ -61,8 +61,8 @@ public:
             return 0;
         }
 
-        if (buff_[toggle_].empty() == true) {
-            if(capture_buffer() == true) {
+        if (buff_[toggle_].size() == 0) {
+            if(capture_buffer() == false) {
                 return 0;
             }
         }
@@ -79,9 +79,12 @@ public:
     }
 
     void clear();
+    void clear_async() {
+        buff_[out_toggle_].clear();
+    }
 
 private:
-    const uint32_t max_buf_size = 0x1800; // 0x1800 - 6144, 0x4000 - 16384, 32768, 0x10000 - 65536, 0x11CA - 4554, 0x0BDC - 3036, 0x100000 - 1Mb
+    const uint32_t max_buf_size = 0x0C00; // 0x0C00 - 3072, 0x1800 - 6144, 0x4000 - 16384, 32768, 0x10000 - 65536, 0x11CA - 4554, 0x0BDC - 3036, 0x100000 - 1Mb
 
     const uint16_t port_dst_be_; /// big endian
     const uint16_t port_src_be_; /// big endian
@@ -102,13 +105,14 @@ private:
     Semaphore rx_sem_;
 
     void put_data(uint8_t * p_data, uint32_t len);
-    int32_t get_data(uint8_t * p_data, uint32_t len);
+    size_t get_data(uint8_t * p_data, uint32_t len);
+    bool capture_buffer();
 
     template<class T, class Allocator>
-    int32_t get_data(std::vector<T, Allocator>& data, uint32_t len)
+    size_t get_data(std::vector<T, Allocator>& data, uint32_t len)
     {
-        std::vector<uint8_t>& buff = buff_[toggle_];
-        uint32_t size = buff.size();
+        std::vector<uint8_t>& buff = buff_[out_toggle_];
+        size_t size = buff.size();
 
         if (size > len) {
             size = len;
@@ -126,6 +130,8 @@ private:
     void set_src_ip(uint32_t src_ip) {
         src_ip_ = src_ip;
     }
+
+    inline uint16_t fill_udp_header(UDPHandlerArgs& udpHandlerArgs);
 };
 
 }
diff --git a/components/free_rtos/ethernet_ip/eth_udp_server.cpp b/components/free_rtos/ethernet_ip/eth_udp_server.cpp
index 3247178..431c1d4 100644
--- a/components/free_rtos/ethernet_ip/eth_udp_server.cpp
+++ b/components/free_rtos/ethernet_ip/eth_udp_server.cpp
@@ -75,7 +75,7 @@ int32_t free_rtos::EthUdpServer::Process(uint8_t * p_data, uint32_t len)
     return 0;
 }
 
-uint32_t free_rtos::EthUdpServer::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
+uint16_t free_rtos::EthUdpServer::Sender(HandlerArgs& handlerArgs, size_t scatter_segment)
 {
     return 0;
 }
diff --git a/components/free_rtos/ethernet_ip/eth_udp_server.hpp b/components/free_rtos/ethernet_ip/eth_udp_server.hpp
index 5b15f02..5a03c31 100644
--- a/components/free_rtos/ethernet_ip/eth_udp_server.hpp
+++ b/components/free_rtos/ethernet_ip/eth_udp_server.hpp
@@ -30,7 +30,7 @@ public:
                                                        bool use_chksum) override;
 
     virtual int32_t Process(uint8_t * p_data, uint32_t len) override;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) override;
 
     virtual int32_t select(uint32_t ticks = SystemP_WAIT_FOREVER) override
     {
diff --git a/components/free_rtos/handler_store/handler.hpp b/components/free_rtos/handler_store/handler.hpp
index c5374ef..437d8a0 100644
--- a/components/free_rtos/handler_store/handler.hpp
+++ b/components/free_rtos/handler_store/handler.hpp
@@ -18,7 +18,7 @@ struct HandlerArgs {
 class Handler {
 public:
     virtual int32_t Process(uint8_t * p_data, uint32_t len) = 0;
-    virtual uint32_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) = 0;
+    virtual uint16_t Sender(HandlerArgs& handlerArgs, size_t scatter_segment) = 0;
 
     ~Handler() {};
 };