diff --git a/packet_registry.c b/packet_registry.c
index e76398b..0be4e11 100644
--- a/packet_registry.c
+++ b/packet_registry.c
@@ -33,11 +33,15 @@ void packreg_add_class(PcktRegistry * packReg, const PcktClassDesc * classDesc)
     }
 
     // append new item
-    packReg->ents[packReg->entCnt] = *classDesc;
+    PcktClassDesc * newEntry = packReg->ents + packReg->entCnt;
+    *newEntry = *classDesc;
+    newEntry->cacheSize = 0; // initialize cache
+    newEntry->cacheArea = NULL;
+
     packReg->entCnt++;
 }
 
-const PcktClassDesc * packreg_get_by_class(const PcktRegistry * packReg, uint16_t ownClass, uint16_t containerClass)  {
+PcktClassDesc * packreg_get_by_class(const PcktRegistry * packReg, uint16_t ownClass, uint16_t containerClass)  {
     uint32_t i;
     for (i = 0; i < packReg->entCnt; i++) {
         const PcktClassDesc * cdesc = packReg->ents + i;
diff --git a/packet_registry.h b/packet_registry.h
index c337587..391040b 100644
--- a/packet_registry.h
+++ b/packet_registry.h
@@ -78,6 +78,9 @@ typedef struct PcktClassDesc_ {
     PcktProcFn procFun; ///< Pckt processing function
     PcktHeaderInsertFn hdrInsFn; ///< Header insert function
     uint16_t propertySize; ///< Size of property structure
+    // -------------------
+    uint16_t cacheSize; ///< Allocated cache size
+    uint8_t * cacheArea; ///< Allocated area for packet header (used as cache area when processing headers)
 } PcktClassDesc;
 
 /**
@@ -110,7 +113,7 @@ void packreg_add_class(PcktRegistry *packReg, const PcktClassDesc *classDesc);
  * @param containerClass container packet's class (if 0, then search by container class is not considered)
  * @return pointer to descriptor on success or NULL on failure
  */
-const PcktClassDesc *packreg_get_by_class(const PcktRegistry *packReg, uint16_t ownClass, uint16_t containerClass);
+PcktClassDesc *packreg_get_by_class(const PcktRegistry *packReg, uint16_t ownClass, uint16_t containerClass);
 
 
 
diff --git a/packet_sieve.c b/packet_sieve.c
index 882d771..2cac3d1 100644
--- a/packet_sieve.c
+++ b/packet_sieve.c
@@ -39,14 +39,26 @@ void packsieve_input(PcktSieve *sieve, const RawPckt *rawPckt) {
 
     do {
         // get packet descriptor
-        const PcktClassDesc *cdesc = packreg_get_by_class(E.pcktReg, ownClass, containerClass);
+        PcktClassDesc *cdesc = packreg_get_by_class(E.pcktReg, ownClass, containerClass);
         if (cdesc == NULL) {
             break;
         }
 
         // allocate property object
         uint32_t hdrSize = ETH_PCKT_HEADER_ELEMENT_HEAD_SIZE + cdesc->propertySize;
-        PcktHeaderElement *header = (PcktHeaderElement *) dynmem_alloc(hdrSize);
+        // look for possible former allocated cache area
+        PcktHeaderElement *header = NULL;
+        if (cdesc->cacheSize <= hdrSize) { // allocate cache area
+            if (cdesc->cacheArea != NULL) {
+                dynmem_free(cdesc->cacheArea);
+            }
+            cdesc->cacheArea = (uint8_t *)dynmem_alloc(hdrSize);
+            ASSERT_NULL(cdesc->cacheArea);
+            cdesc->cacheSize = hdrSize;
+        }
+
+        header = (PcktHeaderElement *)cdesc->cacheArea;
+
         memset(header, 0, hdrSize);
         header->props.ownPacketClass = ownClass;
         header->props.propSize = cdesc->propertySize;
@@ -147,12 +159,12 @@ void packsieve_input(PcktSieve *sieve, const RawPckt *rawPckt) {
 
     // release header chain blocks
     header_release:; // empty line, solely for label placement
-    PcktHeaderElement *iter = outermostHeader;
-    while (iter != NULL) {
-        PcktHeaderElement *next = iter->next;
-        dynmem_free(iter);
-        iter = next;
-    }
+//    PcktHeaderElement *iter = outermostHeader;
+//    while (iter != NULL) {
+//        PcktHeaderElement *next = iter->next;
+//        dynmem_free(iter);
+//        iter = next;
+//    }
     if (procRet == PROC_FN_RET_REPRST) { // if a restart was requested, then run everything again!
         goto restart;
     }