diff --git a/dcmihandler.cpp b/dcmihandler.cpp
index edbca8f..de3d92b 100644
--- a/dcmihandler.cpp
+++ b/dcmihandler.cpp
@@ -37,8 +37,8 @@
 constexpr auto DCMI_OPTION_12_MASK = 0x01;
 constexpr auto DCMI_ACTIVATE_DHCP_MASK = 0x01;
 constexpr auto DCMI_ACTIVATE_DHCP_REPLY = 0x00;
-constexpr auto DCMI_SET_CONF_PARAM_REQ_PACKET_MAX_SIZE = 0x05;
-constexpr auto DCMI_SET_CONF_PARAM_REQ_PACKET_MIN_SIZE = 0x04;
+constexpr auto DCMI_SET_CONF_PARAM_REQ_PACKET_MAX_SIZE = 0x04;
+constexpr auto DCMI_SET_CONF_PARAM_REQ_PACKET_MIN_SIZE = 0x03;
 constexpr auto DHCP_TIMING1 = 0x04;       // 4 sec
 constexpr auto DHCP_TIMING2_UPPER = 0x00; // 2 min
 constexpr auto DHCP_TIMING2_LOWER = 0x78;
@@ -310,18 +310,10 @@
         return IPMI_CC_INVALID;
     }
 
-    auto requestData =
-        reinterpret_cast<const dcmi::GetPowerLimitRequest*>(request);
     std::vector<uint8_t> outPayload(sizeof(dcmi::GetPowerLimitResponse));
     auto responseData =
         reinterpret_cast<dcmi::GetPowerLimitResponse*>(outPayload.data());
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     sdbusplus::bus::bus sdbus{ipmid_get_sd_bus_connection()};
     uint32_t pcapValue = 0;
     bool pcapEnable = false;
@@ -337,8 +329,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
-
     /*
      * Exception action if power limit is exceeded and cannot be controlled
      * with the correction time limit is hardcoded to Hard Power Off system
@@ -380,15 +370,6 @@
 
     auto requestData =
         reinterpret_cast<const dcmi::SetPowerLimitRequest*>(request);
-    std::vector<uint8_t> outPayload(sizeof(dcmi::SetPowerLimitResponse));
-    auto responseData =
-        reinterpret_cast<dcmi::SetPowerLimitResponse*>(outPayload.data());
-
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
 
     sdbusplus::bus::bus sdbus{ipmid_get_sd_bus_connection()};
 
@@ -406,10 +387,7 @@
     log<level::INFO>("Set Power Cap",
                      entry("POWERCAP=%u", requestData->powerLimit));
 
-    responseData->groupID = dcmi::groupExtId;
-    memcpy(response, outPayload.data(), outPayload.size());
-    *data_len = outPayload.size();
-
+    *data_len = 0;
     return IPMI_CC_OK;
 }
 
@@ -426,15 +404,6 @@
 
     auto requestData =
         reinterpret_cast<const dcmi::ApplyPowerLimitRequest*>(request);
-    std::vector<uint8_t> outPayload(sizeof(dcmi::ApplyPowerLimitResponse));
-    auto responseData =
-        reinterpret_cast<dcmi::ApplyPowerLimitResponse*>(outPayload.data());
-
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
 
     sdbusplus::bus::bus sdbus{ipmid_get_sd_bus_connection()};
 
@@ -452,10 +421,7 @@
     log<level::INFO>("Set Power Cap Enable",
                      entry("POWERCAPENABLE=%u", requestData->powerLimitAction));
 
-    responseData->groupID = dcmi::groupExtId;
-    memcpy(response, outPayload.data(), outPayload.size());
-    *data_len = outPayload.size();
-
+    *data_len = 0;
     return IPMI_CC_OK;
 }
 
@@ -469,12 +435,6 @@
     auto responseData =
         reinterpret_cast<dcmi::GetAssetTagResponse*>(outPayload.data());
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     // Verify offset to read and number of bytes to read are not exceeding the
     // range.
     if ((requestData->offset > dcmi::assetTagMaxOffset) ||
@@ -497,8 +457,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
-
     // Return if the asset tag is not populated.
     if (!assetTag.size())
     {
@@ -544,12 +502,6 @@
     auto responseData =
         reinterpret_cast<dcmi::SetAssetTagResponse*>(outPayload.data());
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     // Verify offset to read and number of bytes to read are not exceeding the
     // range.
     if ((requestData->offset > dcmi::assetTagMaxOffset) ||
@@ -580,7 +532,6 @@
 
         dcmi::writeAssetTag(assetTag);
 
-        responseData->groupID = dcmi::groupExtId;
         responseData->tagLength = assetTag.size();
         memcpy(response, outPayload.data(), outPayload.size());
         *data_len = outPayload.size();
@@ -606,8 +557,7 @@
 
     *data_len = 0;
 
-    if (requestData->groupID != dcmi::groupExtId ||
-        requestData->bytes > dcmi::maxBytes ||
+    if (requestData->bytes > dcmi::maxBytes ||
         requestData->offset + requestData->bytes > dcmi::maxCtrlIdStrLen)
     {
         return IPMI_CC_INVALID_FIELD_REQUEST;
@@ -629,7 +579,6 @@
     auto responseStr = hostName.substr(requestData->offset, requestData->bytes);
     auto responseStrLen = std::min(static_cast<std::size_t>(requestData->bytes),
                                    responseStr.length() + 1);
-    responseData->groupID = dcmi::groupExtId;
     responseData->strLen = hostName.length();
     std::copy(begin(responseStr), end(responseStr), responseData->data);
 
@@ -650,8 +599,7 @@
 
     *data_len = 0;
 
-    if (requestData->groupID != dcmi::groupExtId ||
-        requestData->bytes > dcmi::maxBytes ||
+    if (requestData->bytes > dcmi::maxBytes ||
         requestData->offset + requestData->bytes > dcmi::maxCtrlIdStrLen + 1 ||
         (requestData->offset + requestData->bytes ==
              dcmi::maxCtrlIdStrLen + 1 &&
@@ -700,7 +648,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
     responseData->offset = requestData->offset + requestData->bytes;
     *data_len = sizeof(*responseData);
     return IPMI_CC_OK;
@@ -767,12 +714,6 @@
         return IPMI_CC_INVALID_FIELD_REQUEST;
     }
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     auto responseData = reinterpret_cast<dcmi::GetDCMICapResponse*>(response);
 
     // For each capabilities in a parameter fill the data from
@@ -807,7 +748,6 @@
         }
     }
 
-    responseData->groupID = dcmi::groupExtId;
     responseData->major = DCMI_SPEC_MAJOR_VERSION;
     responseData->minor = DCMI_SPEC_MINOR_VERSION;
     responseData->paramRevision = DCMI_PARAMETER_REVISION;
@@ -995,13 +935,6 @@
         return IPMI_CC_INVALID_FIELD_REQUEST;
     }
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        log<level::ERR>("Invalid Group ID",
-                        entry("GROUP_ID=%d", requestData->groupID));
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     if (requestData->sensorType != dcmi::temperatureSensorType)
     {
         log<level::ERR>("Invalid sensor type",
@@ -1034,7 +967,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
     size_t payloadSize = temps.size() * sizeof(dcmi::temp_readings::Response);
     if (!temps.empty())
     {
@@ -1104,19 +1036,15 @@
 {
     auto requestData =
         reinterpret_cast<const dcmi::SetConfParamsRequest*>(request);
-    auto responseData =
-        reinterpret_cast<dcmi::SetConfParamsResponse*>(response);
 
-    if (requestData->groupID != dcmi::groupExtId ||
-        *data_len < DCMI_SET_CONF_PARAM_REQ_PACKET_MIN_SIZE ||
+    if (*data_len < DCMI_SET_CONF_PARAM_REQ_PACKET_MIN_SIZE ||
         *data_len > DCMI_SET_CONF_PARAM_REQ_PACKET_MAX_SIZE)
     {
-        log<level::ERR>("Invalid Group ID or Invalid Requested Packet size",
-                        entry("GROUP_ID=%d", requestData->groupID),
+        log<level::ERR>("Invalid Requested Packet size",
                         entry("PACKET SIZE=%d", *data_len));
+        *data_len = 0;
         return IPMI_CC_INVALID_FIELD_REQUEST;
     }
-
     *data_len = 0;
 
     try
@@ -1168,9 +1096,6 @@
         log<level::ERR>(e.what());
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
-    responseData->groupID = dcmi::groupExtId;
-    *data_len = sizeof(dcmi::SetConfParamsResponse);
-
     return IPMI_CC_OK;
 }
 
@@ -1186,11 +1111,9 @@
 
     responseData->data[0] = 0x00;
 
-    if (requestData->groupID != dcmi::groupExtId ||
-        *data_len != sizeof(dcmi::GetConfParamsRequest))
+    if (*data_len != sizeof(dcmi::GetConfParamsRequest))
     {
-        log<level::ERR>("Invalid Group ID or Invalid Requested Packet size",
-                        entry("GROUP_ID=%d", requestData->groupID),
+        log<level::ERR>("Invalid Requested Packet size",
                         entry("PACKET SIZE=%d", *data_len));
         return IPMI_CC_INVALID_FIELD_REQUEST;
     }
@@ -1240,7 +1163,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
     responseData->major = DCMI_SPEC_MAJOR_VERSION;
     responseData->minor = DCMI_SPEC_MINOR_VERSION;
     responseData->paramRevision = DCMI_CONFIG_PARAMETER_REVISION;
@@ -1260,17 +1182,9 @@
     }
 
     ipmi_ret_t rc = IPMI_CC_OK;
-    auto requestData =
-        reinterpret_cast<const dcmi::GetPowerReadingRequest*>(request);
     auto responseData =
         reinterpret_cast<dcmi::GetPowerReadingResponse*>(response);
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        *data_len = 0;
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     sdbusplus::bus::bus bus{ipmid_get_sd_bus_connection()};
     int64_t power = 0;
     try
@@ -1284,7 +1198,6 @@
                         entry("PROPERTY=%s", SENSOR_VALUE_PROP));
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
-    responseData->groupID = dcmi::groupExtId;
 
     // TODO: openbmc/openbmc#2819
     // Minimum, Maximum, Average power, TimeFrame, TimeStamp,
@@ -1425,13 +1338,6 @@
         return IPMI_CC_INVALID_FIELD_REQUEST;
     }
 
-    if (requestData->groupID != dcmi::groupExtId)
-    {
-        log<level::ERR>("Invalid Group ID",
-                        entry("GROUP_ID=%d", requestData->groupID));
-        return IPMI_CC_INVALID_FIELD_REQUEST;
-    }
-
     if (requestData->sensorType != dcmi::temperatureSensorType)
     {
         log<level::ERR>("Invalid sensor type",
@@ -1473,7 +1379,6 @@
         return IPMI_CC_UNSPECIFIED_ERROR;
     }
 
-    responseData->groupID = dcmi::groupExtId;
     size_t payloadSize = sensors.size() * sizeof(dcmi::sensor_info::Response);
     if (!sensors.empty())
     {
diff --git a/dcmihandler.hpp b/dcmihandler.hpp
index a188c25..4f35bc6 100644
--- a/dcmihandler.hpp
+++ b/dcmihandler.hpp
@@ -129,9 +129,8 @@
  */
 struct GetAssetTagRequest
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t offset;  //!< Offset to read.
-    uint8_t bytes;   //!< Number of bytes to read.
+    uint8_t offset; //!< Offset to read.
+    uint8_t bytes;  //!< Number of bytes to read.
 } __attribute__((packed));
 
 /** @struct GetAssetTagResponse
@@ -140,7 +139,6 @@
  */
 struct GetAssetTagResponse
 {
-    uint8_t groupID;   //!< Group extension identification.
     uint8_t tagLength; //!< Total asset tag length.
 } __attribute__((packed));
 
@@ -150,9 +148,8 @@
  */
 struct SetAssetTagRequest
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t offset;  //!< Offset to write.
-    uint8_t bytes;   //!< Number of bytes to write.
+    uint8_t offset; //!< Offset to write.
+    uint8_t bytes;  //!< Number of bytes to write.
 } __attribute__((packed));
 
 /** @struct SetAssetTagResponse
@@ -161,7 +158,6 @@
  */
 struct SetAssetTagResponse
 {
-    uint8_t groupID;   //!< Group extension identification.
     uint8_t tagLength; //!< Total asset tag length.
 } __attribute__((packed));
 
@@ -211,23 +207,12 @@
  */
 bool getPcapEnabled(sdbusplus::bus::bus& bus);
 
-/** @struct GetPowerLimitRequest
- *
- *  DCMI payload for Get Power Limit command request.
- */
-struct GetPowerLimitRequest
-{
-    uint8_t groupID;   //!< Group extension identification.
-    uint16_t reserved; //!< Reserved
-} __attribute__((packed));
-
 /** @struct GetPowerLimitResponse
  *
  *  DCMI payload for Get Power Limit command response.
  */
 struct GetPowerLimitResponse
 {
-    uint8_t groupID;         //!< Group extension identification.
     uint16_t reserved;       //!< Reserved.
     uint8_t exceptionAction; //!< Exception action.
     uint16_t powerLimit;     //!< Power limit requested in watts.
@@ -249,7 +234,6 @@
  */
 struct SetPowerLimitRequest
 {
-    uint8_t groupID;         //!< Group extension identification.
     uint16_t reserved;       //!< Reserved
     uint8_t reserved1;       //!< Reserved
     uint8_t exceptionAction; //!< Exception action.
@@ -259,15 +243,6 @@
     uint16_t samplingPeriod; //!< Statistics sampling period in seconds.
 } __attribute__((packed));
 
-/** @struct SetPowerLimitResponse
- *
- *  DCMI payload for Set Power Limit command response.
- */
-struct SetPowerLimitResponse
-{
-    uint8_t groupID; //!< Group extension identification.
-} __attribute__((packed));
-
 /** @brief Enable or disable the power capping
  *
  *  @param[in] bus - dbus connection
@@ -281,29 +256,18 @@
  */
 struct ApplyPowerLimitRequest
 {
-    uint8_t groupID;          //!< Group extension identification.
     uint8_t powerLimitAction; //!< Power limit activation
     uint16_t reserved;        //!< Reserved
 } __attribute__((packed));
 
-/** @struct ApplyPowerLimitResponse
- *
- *  DCMI payload for Acticate/Deactivate Power Limit command response.
- */
-struct ApplyPowerLimitResponse
-{
-    uint8_t groupID; //!< Group extension identification.
-} __attribute__((packed));
-
 /** @struct GetMgmntCtrlIdStrRequest
  *
  *  DCMI payload for Get Management Controller Identifier String cmd request.
  */
 struct GetMgmntCtrlIdStrRequest
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t offset;  //!< Offset to read.
-    uint8_t bytes;   //!< Number of bytes to read.
+    uint8_t offset; //!< Offset to read.
+    uint8_t bytes;  //!< Number of bytes to read.
 } __attribute__((packed));
 
 /** @struct GetMgmntCtrlIdStrResponse
@@ -312,9 +276,8 @@
  */
 struct GetMgmntCtrlIdStrResponse
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t strLen;  //!< ID string length.
-    char data[];     //!< ID string
+    uint8_t strLen; //!< ID string length.
+    char data[];    //!< ID string
 } __attribute__((packed));
 
 /** @struct SetMgmntCtrlIdStrRequest
@@ -323,10 +286,9 @@
  */
 struct SetMgmntCtrlIdStrRequest
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t offset;  //!< Offset to write.
-    uint8_t bytes;   //!< Number of bytes to read.
-    char data[];     //!< ID string
+    uint8_t offset; //!< Offset to write.
+    uint8_t bytes;  //!< Number of bytes to read.
+    char data[];    //!< ID string
 } __attribute__((packed));
 
 /** @struct GetMgmntCtrlIdStrResponse
@@ -335,8 +297,7 @@
  */
 struct SetMgmntCtrlIdStrResponse
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t offset;  //!< Last Offset Written.
+    uint8_t offset; //!< Last Offset Written.
 } __attribute__((packed));
 
 /** @enum DCMICapParameters
@@ -357,8 +318,7 @@
  */
 struct GetDCMICapRequest
 {
-    uint8_t groupID; //!< Group extension identification.
-    uint8_t param;   //!< Capability parameter selector.
+    uint8_t param; //!< Capability parameter selector.
 } __attribute__((packed));
 
 /** @struct GetDCMICapRequest
@@ -367,7 +327,6 @@
  */
 struct GetDCMICapResponse
 {
-    uint8_t groupID;       //!< Group extension identification.
     uint8_t major;         //!< DCMI Specification Conformance - major ver
     uint8_t minor;         //!< DCMI Specification Conformance - minor ver
     uint8_t paramRevision; //!< Parameter Revision = 02h
@@ -406,7 +365,6 @@
  */
 struct GetTempReadingsRequest
 {
-    uint8_t groupID;        //!< Group extension identification.
     uint8_t sensorType;     //!< Type of the sensor
     uint8_t entityId;       //!< Entity ID
     uint8_t entityInstance; //!< Entity Instance (0 means all instances)
@@ -419,7 +377,6 @@
  */
 struct GetTempReadingsResponseHdr
 {
-    uint8_t groupID;      //!< Group extension identification.
     uint8_t numInstances; //!< No. of instances for requested id
     uint8_t numDataSets;  //!< No. of sets of temperature data
 } __attribute__((packed));
@@ -526,7 +483,6 @@
  */
 struct GetPowerReadingRequest
 {
-    uint8_t groupID;       //!< Group extension identification.
     uint8_t mode;          //!< Mode
     uint8_t modeAttribute; //!< Mode Attributes
 } __attribute__((packed));
@@ -538,7 +494,6 @@
  */
 struct GetPowerReadingResponse
 {
-    uint8_t groupID;           //!< Group extension identification.
     uint16_t currentPower;     //!< Current power in watts
     uint16_t minimumPower;     //!< Minimum power over sampling duration
                                //!< in watts
@@ -558,7 +513,6 @@
  */
 struct GetSensorInfoRequest
 {
-    uint8_t groupID;        //!< Group extension identification.
     uint8_t sensorType;     //!< Type of the sensor
     uint8_t entityId;       //!< Entity ID
     uint8_t entityInstance; //!< Entity Instance (0 means all instances)
@@ -571,7 +525,6 @@
  */
 struct GetSensorInfoResponseHdr
 {
-    uint8_t groupID;      //!< Group extension identification.
     uint8_t numInstances; //!< No. of instances for requested id
     uint8_t numRecords;   //!< No. of record ids in the response
 } __attribute__((packed));
@@ -594,23 +547,12 @@
  */
 struct SetConfParamsRequest
 {
-    uint8_t groupID;     //!< Group extension identification.
     uint8_t paramSelect; //!< Parameter selector.
     uint8_t setSelect;   //!< Set Selector (use 00h for parameters that only
                          //!< have one set).
     uint8_t data[];      //!< Configuration parameter data.
 } __attribute__((packed));
 
-/** @struct SetConfParamsResponse
- *
- *  DCMI Set DCMI Configuration Parameters Command response.
- *  Refer DCMI specification Version 1.1 Section 6.1.2
- */
-struct SetConfParamsResponse
-{
-    uint8_t groupID; //!< Group extension identification.
-} __attribute__((packed));
-
 /** @struct GetConfParamsRequest
  *
  *  DCMI Get DCMI Configuration Parameters Command.
@@ -618,7 +560,6 @@
  */
 struct GetConfParamsRequest
 {
-    uint8_t groupID;     //!< Group extension identification.
     uint8_t paramSelect; //!< Parameter selector.
     uint8_t setSelect;   //!< Set Selector. Selects a given set of parameters
                          //!< under a given Parameter selector value. 00h if
@@ -632,7 +573,6 @@
  */
 struct GetConfParamsResponse
 {
-    uint8_t groupID;       //!< Group extension identification.
     uint8_t major;         //!< DCMI Spec Conformance - major ver = 01h.
     uint8_t minor;         //!< DCMI Spec Conformance - minor ver = 05h.
     uint8_t paramRevision; //!< Parameter Revision = 01h.
diff --git a/include/ipmid/handler.hpp b/include/ipmid/handler.hpp
index c84bffd..53b0bb8 100644
--- a/include/ipmid/handler.hpp
+++ b/include/ipmid/handler.hpp
@@ -310,17 +310,18 @@
         executeCallback(message::Request::ptr request) override
     {
         message::Response::ptr response = request->makeResponse();
-        size_t len = request->payload.size();
         // allocate a big response buffer here
         response->payload.resize(
             getChannelMaxTransferSize(request->ctx->channel));
 
+        size_t len = request->payload.size() - request->payload.rawIndex;
         Cc ccRet{ccSuccess};
         try
         {
-            ccRet = handler_(request->ctx->netFn, request->ctx->cmd,
-                             request->payload.data(), response->payload.data(),
-                             &len, handlerCtx);
+            ccRet =
+                handler_(request->ctx->netFn, request->ctx->cmd,
+                         request->payload.data() + request->payload.rawIndex,
+                         response->payload.data(), &len, handlerCtx);
         }
         catch (const std::exception& e)
         {
@@ -399,16 +400,18 @@
         executeCallback(message::Request::ptr request) override
     {
         message::Response::ptr response = request->makeResponse();
-        size_t len = request->payload.size();
         // allocate a big response buffer here
         response->payload.resize(
             getChannelMaxTransferSize(request->ctx->channel));
 
+        size_t len = request->payload.size() - request->payload.rawIndex;
         Cc ccRet{ccSuccess};
         try
         {
-            ccRet = handler_(request->ctx->cmd, request->payload.data(),
-                             response->payload.data(), &len);
+            ccRet =
+                handler_(request->ctx->cmd,
+                         request->payload.data() + request->payload.rawIndex,
+                         response->payload.data(), &len);
         }
         catch (const std::exception& e)
         {