diff --git a/src/algo_dup2.c b/src/algo_dup2.c
index 647a978..7750df0 100644
--- a/src/algo_dup2.c
+++ b/src/algo_dup2.c
@@ -20,50 +20,51 @@ int algo_dup2_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo
   char url[256];
   struct evt_core_fdinfo *to_fdinfo = NULL;
   struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
-  union abstract_packet *ap = (union abstract_packet*) &bp->ip, *ap_prev = NULL;
+  union abstract_packet *ap = (union abstract_packet*) &bp->ip;
   struct dup2_ctx* dup2c = app_ctx->misc;
-  uint16_t id = 0;
+  int32_t id = -1, port = -1;
 
-  switch (ap->fmt.headers.cmd) {
-  case CMD_UDP_METADATA_THUNDER:
-    id = ap->fmt.content.udp_metadata_thunder.id;
-    mv_buffer_rtof(&app_ctx->br, fdinfo);
-
-    // Check that received identifier has not been delivered
-    if (ring_ge(dup2c->recv_id, id)) {
-      mv_buffer_atof(&app_ctx->br, fdinfo);
-      return 0;
+  do {
+    switch (ap->fmt.headers.cmd) {
+    case CMD_UDP_METADATA_THUNDER:
+      id = ap->fmt.content.udp_metadata_thunder.id;
+      break;
+    case CMD_UDP_ENCAPSULATED:
+      port = ap->fmt.content.udp_encapsulated.port;
+      break;
+    default:
+      break;
     }
+  } while ((ap = ap_next(ap)) != NULL);
 
-    // Update delivered identifier
-    dup2c->recv_id = id;
-
-    // 1. Find destination
-    ap_prev = (union abstract_packet*) get_app_buffer(&app_ctx->br, fdinfo)->ip;
-    sprintf(url, "udp:write:127.0.0.1:%d", ap_prev->fmt.content.udp_encapsulated.port);
-    to_fdinfo = evt_core_get_from_url (ctx, url);
-    if (to_fdinfo == NULL) {
-      fprintf(stderr, "No fd for URL %s in tcp-read. Dropping packet :( \n", url);
-      mv_buffer_atof (&app_ctx->br, fdinfo);
-      return 1;
-    }
-
-    // 2. Move buffer
-    mv_buffer_atow (&app_ctx->br, fdinfo, to_fdinfo);
-    main_on_udp_write(ctx, to_fdinfo);
-
-    break;
-
-  case CMD_UDP_ENCAPSULATED:
-    mv_buffer_rtoa(&app_ctx->br, fdinfo, fdinfo);
-    break;
-
-  default:
-    fprintf(stderr, "Unknown packet type\n");
-    break;
+  if (port == -1 || id == -1) {
+    fprintf(stderr, "Missing data...");
+    exit(EXIT_FAILURE);
   }
 
-  return 1;
+  // Check that received identifier has not been delivered
+  if (ring_ge(dup2c->recv_id, id)) {
+    mv_buffer_atof(&app_ctx->br, fdinfo);
+    return 0;
+  }
+
+  // Update delivered identifier
+  dup2c->recv_id = id;
+
+  // 1. Find destination
+  sprintf(url, "udp:write:127.0.0.1:%d", port);
+  to_fdinfo = evt_core_get_from_url (ctx, url);
+  if (to_fdinfo == NULL) {
+    fprintf(stderr, "No fd for URL %s in tcp-read. Dropping packet :( \n", url);
+    mv_buffer_atof (&app_ctx->br, fdinfo);
+    return 1;
+  }
+
+  // 2. Move buffer
+  mv_buffer_atow (&app_ctx->br, fdinfo, to_fdinfo);
+  main_on_udp_write(ctx, to_fdinfo);
+
+  return 0;
 }
 
 int algo_dup2_on_datagram(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
@@ -71,9 +72,15 @@ int algo_dup2_on_datagram(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdin
   struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
 
   struct dup2_ctx* dup2c = app_ctx->misc;
-  bp->ip.ap.fmt.content.clear.id = dup2c->emit_id;
-  dup2c->emit_id = dup2c->emit_id + 1;
+  union abstract_packet metadata = {
+    .fmt.headers.cmd = CMD_UDP_METADATA_THUNDER,
+    .fmt.headers.size = sizeof(metadata.fmt.headers) + sizeof(metadata.fmt.content.udp_metadata_thunder),
+    .fmt.headers.flags = 0,
+    .fmt.content.udp_metadata_thunder.id = dup2c->emit_id
+  };
+  buffer_append_ap (bp, &metadata);
 
+  dup2c->emit_id = dup2c->emit_id + 1;
   struct evt_core_cat* cat = evt_core_get_from_cat (ctx, "tcp-write");
 
   for (int i = 0; i < app_ctx->ap.links; i++) {
diff --git a/src/algo_utils.c b/src/algo_utils.c
index be059b0..c17b60a 100644
--- a/src/algo_utils.c
+++ b/src/algo_utils.c
@@ -14,6 +14,11 @@ void naive_free_simple(void* v) {
   g_queue_free (g);
 }
 
+void __push_to_free(struct buffer_resources *app_ctx, struct buffer_packet* bp) {
+  memset(bp, 0, sizeof(struct buffer_packet));
+  g_queue_push_tail (app_ctx->free_buffer, bp);
+}
+
 void debug_buffer(struct buffer_resources *app_ctx, struct evt_core_fdinfo *fdinfo) {
   fprintf(stderr, "No more free buffer for fd=%d.\n", fdinfo->fd);
   int waiting_count = 0;
@@ -34,8 +39,7 @@ void init_buffer_management(struct buffer_resources* ctx) {
   ctx->used_buffer = g_hash_table_new(g_int_hash, g_int_equal);
   ctx->write_waiting = g_hash_table_new_full (g_int_hash, g_int_equal, NULL, naive_free_simple);
   for (int i = 0; i < sizeof(ctx->bps) / sizeof(ctx->bps[0]); i++) {
-    memset(&(ctx->bps[i]), 0, sizeof(struct buffer_packet));
-    g_queue_push_tail(ctx->free_buffer, &(ctx->bps[i]));
+    __push_to_free (ctx, &(ctx->bps[i]));
   }
 }
 
@@ -73,11 +77,6 @@ struct buffer_packet* get_read_buffer(struct buffer_resources *app_ctx, struct e
   return bp;
 }
 
-void __push_to_free(struct buffer_resources *app_ctx, struct buffer_packet* bp) {
-  memset(bp, 0, sizeof(struct buffer_packet));
-  g_queue_push_tail (app_ctx->free_buffer, bp);
-}
-
 guint write_queue_len(struct buffer_resources *app_ctx, struct evt_core_fdinfo *fdinfo) {
   GQueue* q;
 
@@ -104,8 +103,6 @@ struct buffer_packet* get_write_buffer(struct buffer_resources *app_ctx, struct
   // 3. Update state
   g_hash_table_insert(app_ctx->used_buffer, &(fdinfo->fd), bp);
 
-  bp->mode = BP_WRITING;
-  bp->awrite = 0;
   return bp;
 }
 
@@ -256,12 +253,3 @@ void notify_read(struct evt_core_ctx* ctx, struct buffer_resources* app_ctx) {
     }
   }
 }
-
-int append_buffer(union abstract_packet* dest, int pos, union abstract_packet* src) {
-  char* target = &(dest->raw);
-  while (pos-- > 0) {
-    target += ((union abstract_packet*) target)->fmt.headers.size;
-  }
-  memcpy(target, src, src->fmt.headers.size);
-  return 0;
-}
diff --git a/src/algo_utils.h b/src/algo_utils.h
index f2845d1..275923d 100644
--- a/src/algo_utils.h
+++ b/src/algo_utils.h
@@ -26,8 +26,6 @@ void mv_buffer_atof(struct buffer_resources* app_ctx, void* from);
 struct buffer_packet* dup_buffer_tow(struct buffer_resources* app_ctx, struct buffer_packet* bp, struct evt_core_fdinfo* to);
 guint write_queue_len(struct buffer_resources *app_ctx, struct evt_core_fdinfo *fdinfo);
 
-int append_buffer(union abstract_packet* dest, int pos, union abstract_packet* src);
-
 struct buffer_packet* get_write_buffer(struct buffer_resources *app_ctx, struct evt_core_fdinfo *fdinfo);
 struct buffer_packet* get_read_buffer(struct buffer_resources *app_ctx, struct evt_core_fdinfo *fdinfo);
 struct buffer_packet* get_app_buffer(struct buffer_resources *app_ctx, void* idx);
diff --git a/src/capdiff.c b/src/capdiff.c
index 96f73d8..143fc90 100644
--- a/src/capdiff.c
+++ b/src/capdiff.c
@@ -9,11 +9,12 @@
 #define MAX_PKTS_TO_CHECK_FOR_DROP 10
 
 uint8_t are_packets_equal(struct buffer_packet bpread[]) {
-  size_t s1 = bpread[0].ip.ap.fmt.headers.size, s2 = bpread[1].ip.ap.fmt.headers.size;
+  union abstract_packet *ap1 = (union abstract_packet*)&bpread[0].ip, *ap2 = (union abstract_packet*) bpread[1].ip;
+  size_t s1 = ap1->fmt.headers.size, s2 = ap2->fmt.headers.size;
   if (s1 != s2) return 0;
 
-  for (size_t idx = sizeof(bpread[0].ip.ap.fmt.headers) + sizeof(bpread[0].ip.ap.fmt.content.clear) - sizeof(char); idx < s1; idx++) {
-    char e1 = (&bpread[0].ip.ap.raw)[idx], e2 = (&bpread[1].ip.ap.raw)[idx];
+  for (size_t idx = &ap1->fmt.content.udp_encapsulated.payload - (char*)ap1; idx < s1; idx++) {
+    char e1 = (&ap1->raw)[idx], e2 = (&ap2->raw)[idx];
     if (e1 != e2) return 0;
   }
 
@@ -41,7 +42,10 @@ void destroy_pkt_stats(gpointer data) {
 }
 
 void update_stats(struct buffer_packet *bp, GHashTable* stat_elem) {
-  gint port = bp->ip.ap.fmt.content.clear.port;
+  union abstract_packet *ap = (union abstract_packet*)&bp->ip;
+  if (ap->fmt.headers.cmd != CMD_UDP_ENCAPSULATED) return;
+
+  gint port = ap->fmt.content.udp_encapsulated.port;
   struct pkt_stats *ps = g_hash_table_lookup(stat_elem, &port);
   if (ps == NULL) {
     ps = malloc(sizeof(struct pkt_stats));
@@ -57,7 +61,7 @@ void update_stats(struct buffer_packet *bp, GHashTable* stat_elem) {
   }
   ps->last = bp->seen;
   ps->count++;
-  ps->cumulated_size += bp->ip.ap.fmt.headers.size;
+  ps->cumulated_size += ap->fmt.headers.size;
 }
 
 void unroll_packets(struct cap_file cf[], struct buffer_packet bpread[], GHashTable* stats[], struct pkt_reconstruct *pr, int m, int i) {
diff --git a/src/capreplay.c b/src/capreplay.c
index d84873f..dbf5537 100644
--- a/src/capreplay.c
+++ b/src/capreplay.c
@@ -11,7 +11,9 @@ void get_ports(struct cap_file *cf) {
   size_t entry_count = cap_count_bp (cf);
   for (int c = 0; c < entry_count; c++) {
     cap_next_bp (cf, &bp);
-    int a = bp.ip.ap.fmt.content.clear.port;
+    union abstract_packet* ap = (union abstract_packet*) &bp.ip;
+    if (ap->fmt.headers.cmd != CMD_UDP_ENCAPSULATED) continue;
+    int a = ap->fmt.content.udp_encapsulated.port;
   }
   cap_begin(cf);
 }
diff --git a/src/packet.c b/src/packet.c
index f49d6a2..95dcd18 100644
--- a/src/packet.c
+++ b/src/packet.c
@@ -1,15 +1,33 @@
 #include "packet.h"
 
-size_t get_full_size(struct buffer_packet* bp) {
-  union abstract_packet* ap = (union abstract_packet*) &bp->ip;
-  for (int i = 0; i < bp->ap_count; i++) {
-    ap = (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
-  }
-  return &ap->raw - &bp->ip[0];
+union abstract_packet* ap_next(union abstract_packet* ap) {
+  if (ap->fmt.headers.flags & FLAG_READ_NEXT)
+    return (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
+
+  return NULL;
 }
 
-void append_data(struct buffer_packet* bp, char* data, size_t size) {
+union abstract_packet* buffer_last_ptr(struct buffer_packet* bp) {
+  union abstract_packet* ap = (union abstract_packet*) &bp->ip, *apn = NULL;
+  while ((apn = ap_next(ap)) != NULL) ap = apn;
 
+  return ap;
+}
+
+union abstract_packet* buffer_free_ptr(struct buffer_packet* bp) {
+  union abstract_packet* ap = buffer_last_ptr (bp);
+  ap = (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
+
+  return ap;
+}
+
+size_t get_full_size(struct buffer_packet* bp) {
+  return &(buffer_free_ptr (bp))->raw - &bp->ip[0];
+}
+
+void buffer_append_ap(struct buffer_packet* bp, union abstract_packet* ap) {
+  buffer_last_ptr(bp)->fmt.headers.flags |= FLAG_READ_NEXT;
+  memcpy(buffer_last_ptr(bp), ap, ap->fmt.headers.size);
 }
 
 enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
@@ -34,9 +52,11 @@ enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fdinfo, struct buffer
     bp->aread += nread;
   }
 
+  bp->ap_count++;
+  if (bp->ap_count != get_full_size (bp)) return FDS_AGAIN;
+
   bp->mode = BP_WRITING;
   bp->awrite = 0;
-  bp->ap_count = 1;
 
   return FDS_READY;
 }
@@ -62,30 +82,34 @@ enum FD_STATE write_packet_to_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_
 
 enum FD_STATE write_packet_to_udp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp, struct udp_target* udp_t) {
   ssize_t nwrite;
-  union abstract_packet* ap = (union abstract_packet*) &bp->ip;
-
-  size_t bytes_to_send;
-  assert(bp->ip.ap.fmt.headers.cmd == CMD_CLEAR);
-  size_t pkt_header_size = sizeof(ap->fmt.headers);
-  struct sockaddr* addr = NULL;
-  socklen_t addrlen = 0;
-  if (udp_t->set) {
-    addr = (struct sockaddr*) &udp_t->addr;
-    addrlen = sizeof(struct sockaddr_in);
-  }
-
+  union abstract_packet* ap = (union abstract_packet*) (&bp->ip + bp->awrite);
+  union abstract_packet* end = buffer_free_ptr (bp);
   if (bp->mode != BP_WRITING) return FDS_ERR;
 
-  bytes_to_send = ap->fmt.headers.size - pkt_header_size;
-  nwrite = sendto(fdinfo->fd,
+  while (ap != end) {
+    if (ap->fmt.headers.cmd != CMD_UDP_ENCAPSULATED) continue;
+
+    size_t bytes_to_send;
+    size_t pkt_header_size = sizeof(ap->fmt.headers);
+    struct sockaddr* addr = NULL;
+    socklen_t addrlen = 0;
+    if (udp_t->set) {
+      addr = (struct sockaddr*) &udp_t->addr;
+      addrlen = sizeof(struct sockaddr_in);
+    }
+
+    bytes_to_send = ap->fmt.headers.size - pkt_header_size;
+    nwrite = sendto(fdinfo->fd,
                   &(ap->fmt.content.udp_encapsulated),
                   bytes_to_send,
                   0,
                   addr,
                   addrlen);
 
-  if (nwrite == -1 && errno == EAGAIN) return FDS_AGAIN;
-  if (nwrite != bytes_to_send) return FDS_ERR;
+    if (nwrite == -1 && errno == EAGAIN) return FDS_AGAIN;
+    if (nwrite != bytes_to_send) return FDS_ERR;
+    bp->awrite += nwrite;
+  }
 
   bp->mode = BP_READING;
   bp->aread = 0;
diff --git a/src/packet.h b/src/packet.h
index 30cb1d7..5377cd4 100644
--- a/src/packet.h
+++ b/src/packet.h
@@ -37,12 +37,17 @@ enum PKT_CMD {
   CMD_UDP_METADATA_THUNDER,
 };
 
+enum PKT_FLAGS {
+  FLAG_READ_NEXT = 1 << 0,
+};
+
 union abstract_packet {
   char raw;
   struct {
     struct {
       uint16_t size;
-      enum PKT_CMD cmd;
+      uint8_t cmd;
+      uint8_t flags;
     } headers;
 
     union {
@@ -56,7 +61,6 @@ union abstract_packet {
       struct {
         uint16_t id;
         uint16_t deltat;
-
       } udp_metadata_thunder;
       struct {
         uint16_t port;
@@ -84,6 +88,11 @@ struct udp_target {
 
 size_t get_full_size(struct buffer_packet* bp);
 
+void buffer_append_ap(struct buffer_packet* bp, union abstract_packet* ap);
+union abstract_packet* buffer_free_ptr(struct buffer_packet* bp);
+union abstract_packet* buffer_last_ptr(struct buffer_packet* bp);
+union abstract_packet* ap_next(union abstract_packet* ap);
+
 enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fd, struct buffer_packet* bp);
 enum FD_STATE write_packet_to_tcp(struct evt_core_fdinfo* fd, struct buffer_packet* bp);
 enum FD_STATE write_packet_to_udp(struct evt_core_fdinfo* fd, struct buffer_packet* bp, struct udp_target* udp_t);