SCTP I-DATA support

Change-Id: I459942b9e3287d500dda517568252d4cb56d3216
Reviewed-on: https://code.wireshark.org/review/10802
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Petri-Dish: Michael Tüxen <tuexen@wireshark.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Tüxen <tuexen@wireshark.org>

10 files changed, 281 insertions, 89 deletions

diff --git a/epan/dissectors/packet-sctp.c b/epan/dissectors/packet-sctp.c
index 0a500b2be9..21720a7183 100644
--- a/epan/dissectors/packet-sctp.c
+++ b/epan/dissectors/packet-sctp.c
@@ -118,6 +118,9 @@ static int hf_data_chunk_tsn = -1;
 static int hf_data_chunk_stream_id = -1;
 static int hf_data_chunk_stream_seq_number = -1;
 static int hf_data_chunk_payload_proto_id = -1;
+static int hf_idata_chunk_reserved = -1;
+static int hf_idata_chunk_mid = -1;
+static int hf_idata_chunk_fsn = -1;
 
 static int hf_data_chunk_e_bit = -1;
 static int hf_data_chunk_b_bit = -1;
@@ -323,6 +326,7 @@ static dissector_handle_t data_handle;
 #define SCTP_SHUTDOWN_COMPLETE_CHUNK_ID 14
 #define SCTP_AUTH_CHUNK_ID              15
 #define SCTP_NR_SACK_CHUNK_ID           16
+#define SCTP_I_DATA_CHUNK_ID          0x40
 #define SCTP_ASCONF_ACK_CHUNK_ID      0x80
 #define SCTP_PKTDROP_CHUNK_ID         0x81
 #define SCTP_RE_CONFIG_CHUNK_ID       0x82
@@ -349,6 +353,7 @@ static const value_string chunk_type_values[] = {
   { SCTP_SHUTDOWN_COMPLETE_CHUNK_ID, "SHUTDOWN_COMPLETE" },
   { SCTP_AUTH_CHUNK_ID,              "AUTH" },
   { SCTP_NR_SACK_CHUNK_ID,           "NR-SACK" },
+  { SCTP_I_DATA_CHUNK_ID,            "I-DATA" },
   { SCTP_ASCONF_ACK_CHUNK_ID,        "ASCONF_ACK" },
   { SCTP_PKTDROP_CHUNK_ID,           "PKTDROP" },
   { SCTP_RE_CONFIG_CHUNK_ID,         "RE_CONFIG" },
@@ -753,7 +758,10 @@ sctp_both_prompt(packet_info *pinfo, gchar *result)
 static void
 sctp_ppi_prompt1(packet_info *pinfo _U_, gchar* result)
 {
-    guint32 ppid = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 0));
+    guint32 ppid;
+    void *tmp = p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 0);
+
+    ppid = GPOINTER_TO_UINT(tmp);
 
     if (ppid == LAST_PPID) {
         g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "PPID (none)");
@@ -765,7 +773,10 @@ sctp_ppi_prompt1(packet_info *pinfo _U_, gchar* result)
 static void
 sctp_ppi_prompt2(packet_info *pinfo _U_, gchar* result)
 {
-    guint32 ppid = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 1));
+    guint32 ppid;
+    void *tmp = p_get_proto_data(pinfo->pool, pinfo, proto_sctp, 1);
+
+    ppid = GPOINTER_TO_UINT(tmp);
 
     if (ppid == LAST_PPID) {
         g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "PPID (none)");
@@ -933,7 +944,7 @@ static void dissect_error_cause(tvbuff_t *, packet_info *, proto_tree *);
 
 static void dissect_error_causes(tvbuff_t *, packet_info *, proto_tree *);
 
-static gboolean dissect_data_chunk(tvbuff_t*, guint16, packet_info*, proto_tree*, proto_tree*, proto_item*, proto_item*, sctp_half_assoc_t*);
+static gboolean dissect_data_chunk(tvbuff_t*, guint16, packet_info*, proto_tree*, proto_tree*, proto_item*, proto_item*, sctp_half_assoc_t*, gboolean);
 
 static void dissect_sctp_packet(tvbuff_t *, packet_info *, proto_tree *, gboolean);
 
@@ -2533,21 +2544,41 @@ dissect_payload(tvbuff_t *payload_tvb, packet_info *pinfo, proto_tree *tree, gui
 #define DATA_CHUNK_STREAM_ID_LENGTH   2
 #define DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH 2
 #define DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH 4
+#define I_DATA_CHUNK_RESERVED_LENGTH 2
+#define I_DATA_CHUNK_MID_LENGTH 4
+#define I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH 4
+#define I_DATA_CHUNK_FSN_LENGTH 4
 
 #define DATA_CHUNK_TSN_OFFSET         (CHUNK_VALUE_OFFSET + 0)
 #define DATA_CHUNK_STREAM_ID_OFFSET   (DATA_CHUNK_TSN_OFFSET + DATA_CHUNK_TSN_LENGTH)
 #define DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET (DATA_CHUNK_STREAM_ID_OFFSET + \
-                                             DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH)
+                                             DATA_CHUNK_STREAM_ID_LENGTH)
 #define DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET (DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET + \
                                                DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH)
 #define DATA_CHUNK_PAYLOAD_OFFSET     (DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET + \
                                        DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
+#define I_DATA_CHUNK_RESERVED_OFFSET  (DATA_CHUNK_STREAM_ID_OFFSET + \
+                                       DATA_CHUNK_STREAM_ID_LENGTH)
+#define I_DATA_CHUNK_MID_OFFSET       (I_DATA_CHUNK_RESERVED_OFFSET + \
+                                       I_DATA_CHUNK_RESERVED_LENGTH)
+#define I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET (I_DATA_CHUNK_MID_OFFSET + \
+                                                 I_DATA_CHUNK_MID_LENGTH)
+#define I_DATA_CHUNK_FSN_OFFSET       (I_DATA_CHUNK_MID_OFFSET + \
+                                       I_DATA_CHUNK_MID_LENGTH)
+#define I_DATA_CHUNK_PAYLOAD_OFFSET   (I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET + \
+                                       I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
 
 #define DATA_CHUNK_HEADER_LENGTH      (CHUNK_HEADER_LENGTH + \
                                        DATA_CHUNK_TSN_LENGTH + \
                                        DATA_CHUNK_STREAM_ID_LENGTH + \
                                        DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH + \
                                        DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
+#define I_DATA_CHUNK_HEADER_LENGTH    (CHUNK_HEADER_LENGTH + \
+                                       DATA_CHUNK_TSN_LENGTH + \
+                                       DATA_CHUNK_STREAM_ID_LENGTH + \
+                                       I_DATA_CHUNK_RESERVED_LENGTH + \
+                                       I_DATA_CHUNK_MID_LENGTH +\
+                                       I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
 
 #define SCTP_DATA_CHUNK_E_BIT 0x01
 #define SCTP_DATA_CHUNK_B_BIT 0x02
@@ -2563,7 +2594,8 @@ typedef struct _frag_key {
   guint16 dport;
   guint32 verification_tag;
   guint16 stream_id;
-  guint16 stream_seq_num;
+  guint32 stream_seq_num;
+  guint8 u_bit;
 } frag_key;
 
 
@@ -2577,7 +2609,8 @@ frag_equal(gconstpointer k1, gconstpointer k2)
            (key1->dport == key2->dport) &&
            (key1->verification_tag == key2->verification_tag) &&
            (key1->stream_id == key2->stream_id) &&
-           (key1->stream_seq_num == key2->stream_seq_num)
+           (key1->stream_seq_num == key2->stream_seq_num) &&
+           (key1->u_bit == key2->u_bit)
            ? TRUE : FALSE);
 }
 
@@ -2588,7 +2621,7 @@ frag_hash(gconstpointer k)
   const frag_key *key = (const frag_key *) k;
 
   return key->sport ^ key->dport ^ key->verification_tag ^
-         key->stream_id ^ key->stream_seq_num;
+         key->stream_id ^ key->stream_seq_num ^ key->u_bit;
 }
 
 
@@ -2643,7 +2676,7 @@ sctp_cleanup(void)
 
 
 static sctp_frag_msg*
-find_message(guint16 stream_id, guint16 stream_seq_num)
+find_message(guint16 stream_id, guint32 stream_seq_num, guint8 u_bit)
 {
   frag_key key;
 
@@ -2652,18 +2685,19 @@ find_message(guint16 stream_id, guint16 stream_seq_num)
   key.verification_tag = sctp_info.verification_tag;
   key.stream_id = stream_id;
   key.stream_seq_num = stream_seq_num;
+  key.u_bit = u_bit;
 
   return (sctp_frag_msg *)g_hash_table_lookup(frag_table, &key);
 }
 
 
 static sctp_fragment*
-find_fragment(guint32 tsn, guint16 stream_id, guint16 stream_seq_num)
+find_fragment(guint32 tsn, guint16 stream_id, guint32 stream_seq_num, guint8 u_bit)
 {
   sctp_frag_msg *msg;
   sctp_fragment *next_fragment;
 
-  msg = find_message(stream_id, stream_seq_num);
+  msg = find_message(stream_id, stream_seq_num, u_bit);
 
   if (msg) {
     next_fragment = msg->fragments;
@@ -2680,7 +2714,8 @@ find_fragment(guint32 tsn, guint16 stream_id, guint16 stream_seq_num)
 
 static sctp_fragment *
 add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
-             guint16 stream_id, guint16 stream_seq_num, guint8 b_bit, guint8 e_bit)
+             guint16 stream_id, guint32 stream_seq_num, guint8 b_bit, guint8 e_bit,
+             guint8 u_bit, guint32 ppi, gboolean is_idata)
 {
   sctp_frag_msg *msg;
   sctp_fragment *fragment, *last_fragment;
@@ -2692,7 +2727,7 @@ add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
     return NULL;
 
   /* lookup message. if not found, create it */
-  msg = find_message(stream_id, stream_seq_num);
+  msg = find_message(stream_id, stream_seq_num, u_bit);
 
   if (!msg) {
     msg = (sctp_frag_msg *)g_malloc (sizeof (sctp_frag_msg));
@@ -2701,6 +2736,13 @@ add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
     msg->fragments = NULL;
     msg->messages = NULL;
     msg->next = NULL;
+    if (is_idata)
+      if (b_bit)
+        msg->ppi = ppi;
+      else
+        msg->ppi = 0;
+    else
+      msg->ppi = ppi;
 
     key = (frag_key *)g_malloc(sizeof (frag_key));
     key->sport = sctp_info.sport;
@@ -2708,12 +2750,16 @@ add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
     key->verification_tag = sctp_info.verification_tag;
     key->stream_id = stream_id;
     key->stream_seq_num = stream_seq_num;
+    key->u_bit = u_bit;
 
     g_hash_table_insert(frag_table, key, msg);
+  } else {
+      if (b_bit)
+        msg->ppi = ppi;
   }
 
   /* lookup segment. if not found, create it */
-  fragment = find_fragment(tsn, stream_id, stream_seq_num);
+  fragment = find_fragment(tsn, stream_id, stream_seq_num, u_bit);
 
   if (fragment) {
     /* this fragment is already known.
@@ -2746,6 +2792,7 @@ add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
   fragment->frame_num = pinfo->fd->num;
   fragment->tsn = tsn;
   fragment->len = tvb_captured_length(tvb);
+  fragment->ppi = msg->ppi;
   fragment->next = NULL;
   fragment->data = (unsigned char *)g_malloc (fragment->len);
   tvb_memcpy(tvb, fragment->data, 0, fragment->len);
@@ -2826,7 +2873,7 @@ add_fragment(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 tsn,
 static tvbuff_t*
 fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
                     packet_info *pinfo, proto_tree *tree, guint16 stream_id,
-                    guint16 stream_seq_num)
+                    guint32 stream_seq_num, guint8 u_bit)
 {
   sctp_frag_msg *msg;
   sctp_complete_msg *message, *last_message;
@@ -2837,7 +2884,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
   proto_item *item;
   proto_tree *ptree;
 
-  msg = find_message(stream_id, stream_seq_num);
+  msg = find_message(stream_id, stream_seq_num, u_bit);
 
   if (!msg) {
     /* no message, we can't do anything */
@@ -2867,7 +2914,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
                              message->len, message->end - message->begin + 1);
 
       if (message->begin > message->end) {
-        for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num);
+        for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num, u_bit);
              frag_i;
              frag_i = frag_i->next) {
 
@@ -2891,7 +2938,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
           mark_frame_as_depended_upon(pinfo, frag_i->frame_num);
         }
       } else {
-        for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num);
+        for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num, u_bit);
              frag_i && frag_i->tsn <= message->end;
              frag_i = frag_i->next) {
 
@@ -3106,7 +3153,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
                          message->len, message->end - message->begin + 1);
 
   if (message->begin > message->end) {
-    for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num);
+    for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num, u_bit);
          frag_i;
          frag_i = frag_i->next) {
 
@@ -3126,7 +3173,7 @@ fragment_reassembly(tvbuff_t *tvb, sctp_fragment *fragment,
       offset += frag_i->len;
     }
   } else {
-    for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num);
+    for (frag_i = find_fragment(message->begin, stream_id, stream_seq_num, u_bit);
          frag_i && frag_i->tsn <= message->end;
          frag_i = frag_i->next) {
 
@@ -3165,7 +3212,7 @@ export_sctp_data_chunk(packet_info *pinfo, tvbuff_t *tvb, const gchar *proto_nam
 static gboolean
 dissect_fragmented_payload(tvbuff_t *payload_tvb, packet_info *pinfo, proto_tree *tree,
                            proto_tree *chunk_tree, guint32 tsn, guint32 ppi, guint16 stream_id,
-                           guint16 stream_seq_num, guint8 b_bit, guint8 e_bit)
+                           guint32 stream_seq_num, guint8 b_bit, guint8 e_bit, guint8 u_bit, gboolean is_idata)
 {
   sctp_fragment *fragment;
   tvbuff_t *new_tvb = NULL;
@@ -3177,11 +3224,11 @@ dissect_fragmented_payload(tvbuff_t *payload_tvb, packet_info *pinfo, proto_tree
   if (tvb_reported_length(payload_tvb) > tvb_captured_length(payload_tvb))
     return TRUE;
 
-  /* add fragement to list of known fragments. returns NULL if segment is a duplicate */
-  fragment = add_fragment(payload_tvb, pinfo, chunk_tree, tsn, stream_id, stream_seq_num, b_bit, e_bit);
+  /* add fragment to list of known fragments. returns NULL if segment is a duplicate */
+  fragment = add_fragment(payload_tvb, pinfo, chunk_tree, tsn, stream_id, stream_seq_num, b_bit, e_bit, u_bit, ppi, is_idata);
 
   if (fragment)
-    new_tvb = fragment_reassembly(payload_tvb, fragment, pinfo, chunk_tree, stream_id, stream_seq_num);
+    new_tvb = fragment_reassembly(payload_tvb, fragment, pinfo, chunk_tree, stream_id, stream_seq_num, u_bit);
 
   /* pass reassembled data to next dissector, if possible */
   if (new_tvb){
@@ -3189,11 +3236,13 @@ dissect_fragmented_payload(tvbuff_t *payload_tvb, packet_info *pinfo, proto_tree
     guint proto_id;
     const gchar *proto_name;
     gboolean retval;
+    void *tmp;
 
     cur = wmem_list_tail(pinfo->layers);
     retval = dissect_payload(new_tvb, pinfo, tree, ppi);
     cur = wmem_list_frame_next(cur);
-    proto_id = GPOINTER_TO_UINT(wmem_list_frame_data(cur));
+    tmp = wmem_list_frame_data(cur);
+    proto_id = GPOINTER_TO_UINT(tmp);
     proto_name = proto_get_protocol_filter_name(proto_id);
     if(strcmp(proto_name, "data") != 0){
       if (have_tap_listener(exported_pdu_tap)){
@@ -3235,29 +3284,40 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
                    proto_tree *chunk_tree,
                    proto_item *chunk_item,
                    proto_item *flags_item,
-                   sctp_half_assoc_t *ha)
+                   sctp_half_assoc_t *ha,
+                   gboolean is_idata)
 {
   guint number_of_ppid;
-  guint32 payload_proto_id;
+  volatile guint32 payload_proto_id;
   tvbuff_t *payload_tvb;
   proto_tree *flags_tree;
   guint8 e_bit, b_bit, u_bit;
-  guint16 stream_id, stream_seq_num = 0;
-  guint32 tsn, ppid;
+  guint16 stream_id;
+  guint32 tsn, ppid, stream_seq_num = 0;
   proto_item *tsn_item = NULL;
   gboolean call_subdissector = FALSE;
   gboolean is_retransmission;
+  guint16 header_length;
+  guint16 payload_offset;
 
-  if (chunk_length <= DATA_CHUNK_HEADER_LENGTH) {
-    proto_item_append_text(chunk_item, ", bogus chunk length %u < %u)", chunk_length, DATA_CHUNK_HEADER_LENGTH);
-    return TRUE;
+  if (is_idata) {
+    if (chunk_length < I_DATA_CHUNK_HEADER_LENGTH) {
+      proto_item_append_text(chunk_item, ", bogus chunk length %u < %u)", chunk_length, I_DATA_CHUNK_HEADER_LENGTH);
+      return TRUE;
+    }
+    payload_proto_id  = tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET);
+  } else {
+    if (chunk_length < DATA_CHUNK_HEADER_LENGTH) {
+      proto_item_append_text(chunk_item, ", bogus chunk length %u < %u)", chunk_length, DATA_CHUNK_HEADER_LENGTH);
+      return TRUE;
+    }
+    payload_proto_id  = tvb_get_ntohl(chunk_tvb, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET);
   }
 
-  payload_proto_id  = tvb_get_ntohl(chunk_tvb, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET);
-
   /* insert the PPID in the pinfo structure if it is not already there and there is still room */
   for(number_of_ppid = 0; number_of_ppid < MAX_NUMBER_OF_PPIDS; number_of_ppid++) {
-    ppid = GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sctp, number_of_ppid));
+    void *tmp = p_get_proto_data(pinfo->pool, pinfo, proto_sctp, number_of_ppid);
+    ppid = GPOINTER_TO_UINT(tmp);
     if ((ppid == LAST_PPID) || (ppid == payload_proto_id))
       break;
   }
@@ -3267,12 +3327,13 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
   e_bit = tvb_get_guint8(chunk_tvb, CHUNK_FLAGS_OFFSET) & SCTP_DATA_CHUNK_E_BIT;
   b_bit = tvb_get_guint8(chunk_tvb, CHUNK_FLAGS_OFFSET) & SCTP_DATA_CHUNK_B_BIT;
   u_bit = tvb_get_guint8(chunk_tvb, CHUNK_FLAGS_OFFSET) & SCTP_DATA_CHUNK_U_BIT;
-  stream_id = tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET);
-  stream_seq_num = tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET);
   tsn = tvb_get_ntohl(chunk_tvb, DATA_CHUNK_TSN_OFFSET);
 
   if (chunk_tree) {
-    proto_item_set_len(chunk_item, DATA_CHUNK_HEADER_LENGTH);
+    if (is_idata)
+      proto_item_set_len(chunk_item, I_DATA_CHUNK_HEADER_LENGTH);
+    else
+      proto_item_set_len(chunk_item, DATA_CHUNK_HEADER_LENGTH);
     flags_tree  = proto_item_add_subtree(flags_item, ett_sctp_data_chunk_flags);
     proto_tree_add_item(flags_tree, hf_data_chunk_e_bit,             chunk_tvb, CHUNK_FLAGS_OFFSET,                    CHUNK_FLAGS_LENGTH,                    ENC_BIG_ENDIAN);
     proto_tree_add_item(flags_tree, hf_data_chunk_b_bit,             chunk_tvb, CHUNK_FLAGS_OFFSET,                    CHUNK_FLAGS_LENGTH,                    ENC_BIG_ENDIAN);
@@ -3280,9 +3341,17 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
     proto_tree_add_item(flags_tree, hf_data_chunk_i_bit,             chunk_tvb, CHUNK_FLAGS_OFFSET,                    CHUNK_FLAGS_LENGTH,                    ENC_BIG_ENDIAN);
     tsn_item = proto_tree_add_item(chunk_tree, hf_data_chunk_tsn,    chunk_tvb, DATA_CHUNK_TSN_OFFSET,                 DATA_CHUNK_TSN_LENGTH,                 ENC_BIG_ENDIAN);
     proto_tree_add_item(chunk_tree, hf_data_chunk_stream_id,         chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET,           DATA_CHUNK_STREAM_ID_LENGTH,           ENC_BIG_ENDIAN);
-    proto_tree_add_item(chunk_tree, hf_data_chunk_stream_seq_number, chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET,   DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH,   ENC_BIG_ENDIAN);
-    proto_tree_add_item(chunk_tree, hf_data_chunk_payload_proto_id,  chunk_tvb, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH, ENC_BIG_ENDIAN);
-
+    if (is_idata) {
+      proto_tree_add_item(chunk_tree, hf_idata_chunk_reserved, chunk_tvb, I_DATA_CHUNK_RESERVED_OFFSET, I_DATA_CHUNK_RESERVED_LENGTH, ENC_BIG_ENDIAN);
+      proto_tree_add_item(chunk_tree, hf_idata_chunk_mid, chunk_tvb, I_DATA_CHUNK_MID_OFFSET, I_DATA_CHUNK_MID_LENGTH, ENC_BIG_ENDIAN);
+      if (b_bit)
+        proto_tree_add_item(chunk_tree, hf_data_chunk_payload_proto_id,  chunk_tvb, I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET, I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH, ENC_BIG_ENDIAN);
+      else
+        proto_tree_add_item(chunk_tree, hf_idata_chunk_fsn, chunk_tvb, I_DATA_CHUNK_FSN_OFFSET, I_DATA_CHUNK_FSN_LENGTH, ENC_BIG_ENDIAN);
+    } else {
+      proto_tree_add_item(chunk_tree, hf_data_chunk_stream_seq_number, chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET,   DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH,   ENC_BIG_ENDIAN);
+      proto_tree_add_item(chunk_tree, hf_data_chunk_payload_proto_id,  chunk_tvb, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET, DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH, ENC_BIG_ENDIAN);
+    }
     proto_item_append_text(chunk_item, "(%s, ", (u_bit) ? "unordered" : "ordered");
     if (b_bit) {
       if (e_bit)
@@ -3296,19 +3365,41 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
         proto_item_append_text(chunk_item, "middle");
     }
 
-    proto_item_append_text(chunk_item, " segment, TSN: %u, SID: %u, SSN: %u, PPID: %u, payload length: %u byte%s)",
-                           tvb_get_ntohl(chunk_tvb, DATA_CHUNK_TSN_OFFSET),
-                           tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET),
-                           tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET),
-                           payload_proto_id,
-                           chunk_length - DATA_CHUNK_HEADER_LENGTH, plurality(chunk_length - DATA_CHUNK_HEADER_LENGTH, "", "s"));
+    if (is_idata) {
+      if (b_bit)
+        proto_item_append_text(chunk_item, " segment, TSN: %u, SID: %u, MID: %u, payload length: %u byte%s)",
+                               tvb_get_ntohl(chunk_tvb, DATA_CHUNK_TSN_OFFSET),
+                               tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET),
+                               tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_MID_OFFSET),
+                               chunk_length - I_DATA_CHUNK_HEADER_LENGTH, plurality(chunk_length - I_DATA_CHUNK_HEADER_LENGTH, "", "s"));
+      else
+        proto_item_append_text(chunk_item, " segment, TSN: %u, SID: %u, MID: %u, FSN: %u, payload length: %u byte%s)",
+                               tvb_get_ntohl(chunk_tvb, DATA_CHUNK_TSN_OFFSET),
+                               tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET),
+                               tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_MID_OFFSET),
+                               tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_FSN_OFFSET),
+                               chunk_length - I_DATA_CHUNK_HEADER_LENGTH, plurality(chunk_length - I_DATA_CHUNK_HEADER_LENGTH, "", "s"));
+    } else
+      proto_item_append_text(chunk_item, " segment, TSN: %u, SID: %u, SSN: %u, PPID: %u, payload length: %u byte%s)",
+                             tvb_get_ntohl(chunk_tvb, DATA_CHUNK_TSN_OFFSET),
+                             tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET),
+                             tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET),
+                             payload_proto_id,
+                             chunk_length - DATA_CHUNK_HEADER_LENGTH, plurality(chunk_length - DATA_CHUNK_HEADER_LENGTH, "", "s"));
   }
 
-  is_retransmission = sctp_tsn(pinfo,  chunk_tvb, tsn_item, ha, tsn);
+  is_retransmission = sctp_tsn(pinfo, chunk_tvb, tsn_item, ha, tsn);
 
-  payload_tvb = tvb_new_subset(chunk_tvb, DATA_CHUNK_PAYLOAD_OFFSET,
-                               MIN(chunk_length - DATA_CHUNK_HEADER_LENGTH, tvb_captured_length_remaining(chunk_tvb, DATA_CHUNK_PAYLOAD_OFFSET)),
-                               MIN(chunk_length - DATA_CHUNK_HEADER_LENGTH, tvb_reported_length_remaining(chunk_tvb, DATA_CHUNK_PAYLOAD_OFFSET)));
+  if (is_idata) {
+    header_length = I_DATA_CHUNK_HEADER_LENGTH;
+    payload_offset = I_DATA_CHUNK_PAYLOAD_OFFSET;
+  } else {
+    header_length = DATA_CHUNK_HEADER_LENGTH;
+    payload_offset = DATA_CHUNK_PAYLOAD_OFFSET;
+  }
+  payload_tvb = tvb_new_subset(chunk_tvb, I_DATA_CHUNK_PAYLOAD_OFFSET,
+                                 MIN(chunk_length - header_length, tvb_captured_length_remaining(chunk_tvb, payload_offset)),
+                                 MIN(chunk_length - header_length, tvb_reported_length_remaining(chunk_tvb, payload_offset)));
 
   /* Is this a fragment? */
   if (b_bit && e_bit) {
@@ -3343,13 +3434,15 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
       wmem_list_frame_t *cur;
       guint proto_id;
       const gchar *proto_name;
+      void *tmp;
 
       cur = wmem_list_tail(pinfo->layers);
       retval = dissect_payload(payload_tvb, pinfo, tree, payload_proto_id);
       cur = wmem_list_frame_next(cur);
-      proto_id = GPOINTER_TO_UINT(wmem_list_frame_data(cur));
+      tmp = wmem_list_frame_data(cur);
+      proto_id = GPOINTER_TO_UINT(tmp);
       proto_name = proto_get_protocol_filter_name(proto_id);
-      if(strcmp(proto_name, "data") != 0){
+      if (strcmp(proto_name, "data") != 0){
         if (have_tap_listener(exported_pdu_tap)){
           export_sctp_data_chunk(pinfo,payload_tvb, proto_name);
         }
@@ -3378,12 +3471,25 @@ dissect_data_chunk(tvbuff_t *chunk_tvb,
     /* The logic above should ensure this... */
     DISSECTOR_ASSERT(use_reassembly);
 
-    /* if unordered set stream_seq_num to 0 for easier handling */
-    if (u_bit)
-      stream_seq_num = 0;
-
+    stream_id = tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_ID_OFFSET);
+    if (is_idata) {
+      /* The stream_seq_num variable is used to hold the MID, the tsn variable holds the FSN*/
+      stream_seq_num = tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_MID_OFFSET);
+      if (b_bit) {
+        tsn = 0;
+      } else {
+        tsn = tvb_get_ntohl(chunk_tvb, I_DATA_CHUNK_FSN_OFFSET);
+        payload_proto_id = 0;
+      }
+    } else {
+      /* if unordered set stream_seq_num to 0 for easier handling */
+      if (u_bit)
+        stream_seq_num = 0;
+      else
+        stream_seq_num = tvb_get_ntohs(chunk_tvb, DATA_CHUNK_STREAM_SEQ_NUMBER_OFFSET);
+    }
     /* start reassembly */
-    return dissect_fragmented_payload(payload_tvb, pinfo, tree, chunk_tree, tsn, payload_proto_id, stream_id, stream_seq_num, b_bit, e_bit);
+    return dissect_fragmented_payload(payload_tvb, pinfo, tree, chunk_tree, tsn, payload_proto_id, stream_id, stream_seq_num, b_bit, e_bit, u_bit, is_idata);
   }
 
 }
@@ -4246,7 +4352,10 @@ dissect_sctp_chunk(tvbuff_t *chunk_tvb,
   /* now dissect the chunk value */
   switch(type) {
   case SCTP_DATA_CHUNK_ID:
-    result = dissect_data_chunk(chunk_tvb, length, pinfo, tree, chunk_tree, chunk_item, flags_item, ha);
+    result = dissect_data_chunk(chunk_tvb, length, pinfo, tree, chunk_tree, chunk_item, flags_item, ha, FALSE);
+    break;
+  case SCTP_I_DATA_CHUNK_ID:
+    result = dissect_data_chunk(chunk_tvb, length, pinfo, tree, chunk_tree, chunk_item, flags_item, ha, TRUE);
     break;
   case SCTP_INIT_CHUNK_ID:
     dissect_init_chunk(chunk_tvb, length, pinfo, chunk_tree, chunk_item);
@@ -4655,10 +4764,13 @@ proto_register_sctp(void)
 #if 0
     { &hf_cumulative_tsn_ack,                       { "Cumulative TSN Ack",                             "sctp.cumulative_tsn_ack",                              FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
 #endif
-    { &hf_data_chunk_tsn,                           { "TSN",                                            "sctp.data_tsn",                                        FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
-    { &hf_data_chunk_stream_id,                     { "Stream Identifier",                              "sctp.data_sid",                                        FT_UINT16,  BASE_HEX,  NULL,                                           0x0,                                NULL, HFILL } },
+    { &hf_data_chunk_tsn,                           { "Transmission sequence number",                   "sctp.data_tsn",                                        FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
+    { &hf_data_chunk_stream_id,                     { "Stream identifier",                              "sctp.data_sid",                                        FT_UINT16,  BASE_HEX,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_data_chunk_stream_seq_number,             { "Stream sequence number",                         "sctp.data_ssn",                                        FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_data_chunk_payload_proto_id,              { "Payload protocol identifier",                    "sctp.data_payload_proto_id",                           FT_UINT32,  BASE_DEC,  VALS(sctp_payload_proto_id_values),             0x0,                                NULL, HFILL } },
+    { &hf_idata_chunk_reserved,                     { "Reserved",                                       "sctp.data_reserved",                                   FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
+    { &hf_idata_chunk_mid,                          { "Message identifier",                             "sctp.data_mid",                                        FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
+    { &hf_idata_chunk_fsn,                          { "Fragment sequence number",                       "sctp.data_fsn",                                        FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_data_chunk_e_bit,                         { "E-Bit",                                          "sctp.data_e_bit",                                      FT_BOOLEAN, 8,         TFS(&sctp_data_chunk_e_bit_value),              SCTP_DATA_CHUNK_E_BIT,              NULL, HFILL } },
     { &hf_data_chunk_b_bit,                         { "B-Bit",                                          "sctp.data_b_bit",                                      FT_BOOLEAN, 8,         TFS(&sctp_data_chunk_b_bit_value),              SCTP_DATA_CHUNK_B_BIT,              NULL, HFILL } },
     { &hf_data_chunk_u_bit,                         { "U-Bit",                                          "sctp.data_u_bit",                                      FT_BOOLEAN, 8,         TFS(&sctp_data_chunk_u_bit_value),              SCTP_DATA_CHUNK_U_BIT,              NULL, HFILL } },
diff --git a/epan/dissectors/packet-sctp.h b/epan/dissectors/packet-sctp.h
index 237145b8e0..8b2022e075 100644
--- a/epan/dissectors/packet-sctp.h
+++ b/epan/dissectors/packet-sctp.h
@@ -51,6 +51,7 @@ typedef struct _sctp_fragment {
   guint32 frame_num;
   guint32 tsn;
   guint32 len;
+  guint32 ppi;
   unsigned char *data;
   struct _sctp_fragment *next;
 } sctp_fragment;
@@ -74,6 +75,7 @@ typedef struct _sctp_frag_msg {
   sctp_frag_be* ends;
   sctp_fragment* fragments;
   sctp_complete_msg* messages;
+  guint32 ppi;
   struct _sctp_frag_msg* next;
 } sctp_frag_msg;
 
diff --git a/ui/gtk/sctp_chunk_stat.c b/ui/gtk/sctp_chunk_stat.c
index e4266e0df2..8b85c90ed1 100644
--- a/ui/gtk/sctp_chunk_stat.c
+++ b/ui/gtk/sctp_chunk_stat.c
@@ -207,11 +207,12 @@ sctpstat_draw(void *phs)
 		12, tmp->chunk_count[SCTP_ABORT_CHUNK_ID],
 		13, tmp->chunk_count[SCTP_ERROR_CHUNK_ID],
 		14, tmp->chunk_count[SCTP_NR_SACK_CHUNK_ID],
-		15, tmp->chunk_count[SCTP_ASCONF_ACK_CHUNK_ID],
-		16, tmp->chunk_count[SCTP_PKTDROP_CHUNK_ID],
-		17, tmp->chunk_count[SCTP_FORWARD_TSN_CHUNK_ID],
-		18, tmp->chunk_count[SCTP_ASCONF_CHUNK_ID],
-		19, tmp->chunk_count[OTHER_CHUNKS_INDEX],
+		15, tmp->chunk_count[SCTP_I_DATA_CHUNK_ID],
+		16, tmp->chunk_count[SCTP_ASCONF_ACK_CHUNK_ID],
+		17, tmp->chunk_count[SCTP_PKTDROP_CHUNK_ID],
+		18, tmp->chunk_count[SCTP_FORWARD_TSN_CHUNK_ID],
+		19, tmp->chunk_count[SCTP_ASCONF_CHUNK_ID],
+		20, tmp->chunk_count[OTHER_CHUNKS_INDEX],
 		-1
 		);
 		wmem_free(NULL, src_addr);
@@ -250,6 +251,7 @@ static const stat_column titles[]={
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "ABORT" },
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "ERROR" },
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "NR-SACK" },
+	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "I-DATA" },
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "ASCONF-ACK" },
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "PKTDROP" },
 	{G_TYPE_UINT, TAP_ALIGN_RIGHT,  "FORWARD-TSN" },
diff --git a/ui/gtk/sctp_chunk_stat_dlg.c b/ui/gtk/sctp_chunk_stat_dlg.c
index 7308ee01bf..9cdbad045b 100644
--- a/ui/gtk/sctp_chunk_stat_dlg.c
+++ b/ui/gtk/sctp_chunk_stat_dlg.c
@@ -56,6 +56,7 @@ enum chunk_types {
     SHUT_COMPLETE = 14,
     AUTH          = 15,
     NR_SACK       = 16,
+    I_DATA        = 0x40,
     ASCONF_ACK    = 0x80,
     PKTDROP       = 0x81,
     FORWARD_TSN   = 0xC0,
@@ -81,6 +82,7 @@ enum
     SHUT_COMPLETE_COLUMN,
     AUTH_COLUMN,
     NR_SACK_COLUMN,
+    I_DATA_COLUMN,
     ASCONF_ACK_COLUMN,
     PKTDROP_COLUMN,
     FORWARD_TSN_COLUMN,
@@ -122,6 +124,7 @@ GtkWidget* create_list(void)
                                     G_TYPE_INT,    /* SHUT_COMPLETE               */
                                     G_TYPE_INT,    /* AUTH                        */
                                     G_TYPE_INT,    /* NR_SACK                     */
+                                    G_TYPE_INT,    /* I_DATA                      */
                                     G_TYPE_INT,    /* ASCONF_ACK                  */
                                     G_TYPE_INT,    /* PKTDROP                     */
                                     G_TYPE_INT,    /* FORWARD_TSN                 */
@@ -351,6 +354,17 @@ GtkWidget* create_list(void)
 
     /* 19:th column... */
     renderer = gtk_cell_renderer_text_new ();
+    column = gtk_tree_view_column_new_with_attributes ("I-DATA", renderer,
+                "text", I_DATA_COLUMN,
+                NULL);
+    gtk_tree_view_column_set_sort_column_id(column, I_DATA_COLUMN);
+    gtk_tree_view_column_set_resizable(column, TRUE);
+    gtk_tree_view_column_set_sizing(column, GTK_TREE_VIEW_COLUMN_FIXED);
+    gtk_tree_view_column_set_min_width(column, 100);
+    gtk_tree_view_append_column (list_view, column);
+
+    /* 20:th column... */
+    renderer = gtk_cell_renderer_text_new ();
     column = gtk_tree_view_column_new_with_attributes ("ASCONF-ACK", renderer,
                 "text", ASCONF_ACK_COLUMN,
                 NULL);
@@ -360,7 +374,7 @@ GtkWidget* create_list(void)
     gtk_tree_view_column_set_min_width(column, 120);
     gtk_tree_view_append_column (list_view, column);
 
-    /* 20:th column... */
+    /* 21:th column... */
     renderer = gtk_cell_renderer_text_new ();
     column = gtk_tree_view_column_new_with_attributes ("PKTDROP", renderer,
                 "text", PKTDROP_COLUMN,
@@ -371,7 +385,7 @@ GtkWidget* create_list(void)
     gtk_tree_view_column_set_min_width(column, 100);
     gtk_tree_view_append_column (list_view, column);
 
-    /* 21:st column... */
+    /* 22:st column... */
     renderer = gtk_cell_renderer_text_new ();
     column = gtk_tree_view_column_new_with_attributes ("FORWARD-TSN", renderer,
                 "text", FORWARD_TSN_COLUMN,
@@ -382,7 +396,7 @@ GtkWidget* create_list(void)
     gtk_tree_view_column_set_min_width(column, 140);
     gtk_tree_view_append_column (list_view, column);
 
-    /* 22:nd column... */
+    /* 23:nd column... */
     renderer = gtk_cell_renderer_text_new ();
     column = gtk_tree_view_column_new_with_attributes ("ASCONF", renderer,
                 "text", ASCONF_COLUMN,
@@ -393,7 +407,7 @@ GtkWidget* create_list(void)
     gtk_tree_view_column_set_min_width(column, 90);
     gtk_tree_view_append_column (list_view, column);
 
-    /* 23:rd column... */
+    /* 24:rd column... */
     renderer = gtk_cell_renderer_text_new ();
     column = gtk_tree_view_column_new_with_attributes ("Others", renderer,
                 "text", OTHERS_COLUMN,
@@ -440,6 +454,7 @@ chunk_name(int type)
         CASE(SHUT_COMPLETE);
         CASE(AUTH);
         CASE(NR_SACK);
+        CASE(I_DATA);
         CASE(ASCONF_ACK);
         CASE(PKTDROP);
         CASE(FORWARD_TSN);
@@ -494,7 +509,7 @@ add_to_clist(sctp_addr_chunk* sac)
     }
 
     gtk_list_store_insert_with_values( list_store , &iter, G_MAXINT,
-         IP_ADDR_COLUMN,         field[0],
+         IP_ADDR_COLUMN,         field,
          DATA_COLUMN,            sac->addr_count[SCTP_DATA_CHUNK_ID],
          INIT_COLUMN,            sac->addr_count[SCTP_INIT_CHUNK_ID],
          INIT_ACK_COLUMN,        sac->addr_count[SCTP_INIT_ACK_CHUNK_ID],
@@ -512,6 +527,7 @@ add_to_clist(sctp_addr_chunk* sac)
          SHUT_COMPLETE_COLUMN,   sac->addr_count[SCTP_SHUTDOWN_COMPLETE_CHUNK_ID],
          AUTH_COLUMN,            sac->addr_count[SCTP_AUTH_CHUNK_ID],
          NR_SACK_COLUMN,         sac->addr_count[SCTP_NR_SACK_CHUNK_ID],
+         I_DATA_COLUMN,          sac->addr_count[SCTP_I_DATA_CHUNK_ID],
          ASCONF_ACK_COLUMN,      sac->addr_count[SCTP_ASCONF_ACK_CHUNK_ID],
          PKTDROP_COLUMN,         sac->addr_count[SCTP_PKTDROP_CHUNK_ID],
          FORWARD_TSN_COLUMN,     sac->addr_count[SCTP_FORWARD_TSN_CHUNK_ID],
diff --git a/ui/gtk/sctp_graph_dlg.c b/ui/gtk/sctp_graph_dlg.c
index f702a68491..0811c3671c 100644
--- a/ui/gtk/sctp_graph_dlg.c
+++ b/ui/gtk/sctp_graph_dlg.c
@@ -569,7 +569,7 @@ draw_tsn_graph(struct sctp_udata *u_data)
 		while (tlist)
 		{
 			type = ((struct chunk_header *)tlist->data)->type;
-			if (type == SCTP_DATA_CHUNK_ID || type == SCTP_FORWARD_TSN_CHUNK_ID)
+			if (type == SCTP_DATA_CHUNK_ID || type == SCTP_I_DATA_CHUNK_ID || type == SCTP_FORWARD_TSN_CHUNK_ID)
 				tsnumber = g_ntohl(((struct data_chunk_header *)tlist->data)->tsn);
 			if (tsnumber >= min_tsn && tsnumber <= max_tsn && tsn->secs >= min_secs)
 			{
@@ -589,7 +589,7 @@ draw_tsn_graph(struct sctp_udata *u_data)
 #else
 					cr = gdk_cairo_create (u_data->io->pixmap);
 #endif
-					if (type == SCTP_DATA_CHUNK_ID)
+					if ((type == SCTP_DATA_CHUNK_ID) || (type == SCTP_I_DATA_CHUNK_ID))
 						gdk_cairo_set_source_rgba (cr, &black_color);
 					else
 						gdk_cairo_set_source_rgba (cr, &pink_color);
diff --git a/ui/qt/sctp_graph_arwnd_dialog.cpp b/ui/qt/sctp_graph_arwnd_dialog.cpp
index abaeb5832a..a36e5bdfbd 100644
--- a/ui/qt/sctp_graph_arwnd_dialog.cpp
+++ b/ui/qt/sctp_graph_arwnd_dialog.cpp
@@ -76,10 +76,10 @@ void SCTPGraphArwndDialog::drawArwndGraph()
 
     if (direction == 1) {
         listSACK = g_list_last(selected_assoc->sack1);
-        startArwnd = selected_assoc->arwnd1;
+        startArwnd = selected_assoc->arwnd2;
     } else {
         listSACK = g_list_last(selected_assoc->sack2);
-        startArwnd = selected_assoc->arwnd2;
+        startArwnd = selected_assoc->arwnd1;
     }
     while (listSACK) {
         tsn = (tsn_t*) (listSACK->data);
diff --git a/ui/qt/sctp_graph_byte_dialog.cpp b/ui/qt/sctp_graph_byte_dialog.cpp
index 2d24ba73d2..4af5a847e2 100644
--- a/ui/qt/sctp_graph_byte_dialog.cpp
+++ b/ui/qt/sctp_graph_byte_dialog.cpp
@@ -90,8 +90,12 @@ void SCTPGraphByteDialog::drawBytesGraph()
         while (tlist)
         {
             type = ((struct chunk_header *)tlist->data)->type;
-            if (type == SCTP_DATA_CHUNK_ID) {
+            if (type == SCTP_DATA_CHUNK_ID || type == SCTP_I_DATA_CHUNK_ID) {
                 length = g_ntohs(((struct data_chunk_header *)tlist->data)->length);
+                if (type == SCTP_DATA_CHUNK_ID)
+                    length -= DATA_CHUNK_HEADER_LENGTH;
+                else
+                    length -= I_DATA_CHUNK_HEADER_LENGTH;
                 sumBytes += length;
                 yb.append(sumBytes);
                 xb.append(tsn->secs + tsn->usecs/1000000.0);
diff --git a/ui/qt/sctp_graph_dialog.cpp b/ui/qt/sctp_graph_dialog.cpp
index 27cc4bb0c8..d0efcf5f57 100644
--- a/ui/qt/sctp_graph_dialog.cpp
+++ b/ui/qt/sctp_graph_dialog.cpp
@@ -86,8 +86,8 @@ void SCTPGraphDialog::drawNRSACKGraph()
         list = g_list_last(selected_assoc->sack1);
         min_tsn = selected_assoc->min_tsn1;
     } else {
-        list = g_list_last(selected_assoc->sack1);
-        min_tsn = selected_assoc->min_tsn1;
+        list = g_list_last(selected_assoc->sack2);
+        min_tsn = selected_assoc->min_tsn2;
     }
     while (list) {
         sack = (tsn_t*) (list->data);
@@ -280,7 +280,7 @@ void SCTPGraphDialog::drawTSNGraph()
         while (tlist)
         {
             type = ((struct chunk_header *)tlist->data)->type;
-            if (type == SCTP_DATA_CHUNK_ID || type == SCTP_FORWARD_TSN_CHUNK_ID) {
+            if (type == SCTP_DATA_CHUNK_ID || type == SCTP_I_DATA_CHUNK_ID || type == SCTP_FORWARD_TSN_CHUNK_ID) {
                 tsnumber = g_ntohl(((struct data_chunk_header *)tlist->data)->tsn);
                 yt.append(tsnumber);
                 xt.append(tsn->secs + tsn->usecs/1000000.0);
@@ -314,6 +314,7 @@ void SCTPGraphDialog::drawTSNGraph()
 void SCTPGraphDialog::drawGraph(int which)
 {
     guint32 maxTSN, minTSN;
+    gint64 minBound;
 
     gIsSackChunkPresent = false;
     gIsNRSackChunkPresent = false;
@@ -348,7 +349,12 @@ void SCTPGraphDialog::drawGraph(int which)
     connect(ui->sctpPlot, SIGNAL(plottableClick(QCPAbstractPlottable*,QMouseEvent*)), this, SLOT(graphClicked(QCPAbstractPlottable*, QMouseEvent*)));
     // set axes ranges, so we see all data:
     QCPRange myXRange(selected_assoc->min_secs, (selected_assoc->max_secs+1));
-    QCPRange myYRange(minTSN, maxTSN);
+    if (maxTSN - minTSN < 5) {
+        minBound = 0;
+    } else {
+        minBound = minTSN;
+    }
+    QCPRange myYRange(minBound, maxTSN);
     ui->sctpPlot->xAxis->setRange(myXRange);
     ui->sctpPlot->yAxis->setRange(myYRange);
     ui->sctpPlot->replot();
diff --git a/ui/tap-sctp-analysis.c b/ui/tap-sctp-analysis.c
index 6652fe705e..6e3db28f4c 100644
--- a/ui/tap-sctp-analysis.c
+++ b/ui/tap-sctp-analysis.c
@@ -478,6 +478,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 			if (((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_INIT_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_INIT_ACK_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_DATA_CHUNK_ID) ||
+			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_I_DATA_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_SACK_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_NR_SACK_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_FORWARD_TSN_CHUNK_ID))
@@ -507,6 +508,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 				sack->secs=tsn->secs   = (guint32)pinfo->rel_ts.secs;
 				sack->usecs=tsn->usecs = (guint32)pinfo->rel_ts.nsecs/1000;
 				if (((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_DATA_CHUNK_ID) ||
+				    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_I_DATA_CHUNK_ID) ||
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_SACK_CHUNK_ID) ||
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_NR_SACK_CHUNK_ID) ||
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_FORWARD_TSN_CHUNK_ID))
@@ -583,6 +585,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 				if (((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_INIT_CHUNK_ID) &&
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_INIT_ACK_CHUNK_ID) &&
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_DATA_CHUNK_ID) &&
+				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_I_DATA_CHUNK_ID) &&
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_SACK_CHUNK_ID) &&
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_NR_SACK_CHUNK_ID) &&
 				    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_FORWARD_TSN_CHUNK_ID))
@@ -604,10 +607,15 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 					info->ep1_chunk_count[idx]++;
 					info = add_chunk_count(&tmp_info.src, info, 1, idx);
 
-					if ((tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID))
+					if ((tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) ||
+						(tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_I_DATA_CHUNK_ID))
 					{
 						datachunk = TRUE;
-						length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET)-DATA_CHUNK_HEADER_LENGTH;
+						if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) {
+							length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - DATA_CHUNK_HEADER_LENGTH;
+						} else {
+							length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - I_DATA_CHUNK_HEADER_LENGTH;
+						}
 						info->n_data_chunks++;
 						info->n_data_bytes+=length;
 						info->outstream1 = tvb_get_ntohs((sctp_info->tvb)[chunk_number], DATA_CHUNK_STREAM_ID_OFFSET)+1;
@@ -655,7 +663,11 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 						tsn_s->offset   = 0;
 						tsn_s->framenumber = framenumber;
 						if (datachunk)
-							tsn_s->length   = length-DATA_CHUNK_HEADER_LENGTH;
+							if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) {
+								tsn_s->length   = length - DATA_CHUNK_HEADER_LENGTH;
+							} else {
+								tsn_s->length   = length - I_DATA_CHUNK_HEADER_LENGTH;
+							}
 						else
 							tsn_s->length   = length;
 						if (tsn->secs < info->min_secs)
@@ -781,6 +793,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 		if (((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_INIT_CHUNK_ID) ||
 		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_INIT_ACK_CHUNK_ID) ||
 		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_DATA_CHUNK_ID) ||
+		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_I_DATA_CHUNK_ID) ||
 		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_SACK_CHUNK_ID) ||
 		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_NR_SACK_CHUNK_ID) ||
 		    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_FORWARD_TSN_CHUNK_ID))
@@ -811,6 +824,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 			sack->secs=tsn->secs = (guint32)pinfo->rel_ts.secs;
 			sack->usecs=tsn->usecs = (guint32)pinfo->rel_ts.nsecs/1000;
 			if (((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_DATA_CHUNK_ID) ||
+			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_I_DATA_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_SACK_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_NR_SACK_CHUNK_ID) ||
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) == SCTP_FORWARD_TSN_CHUNK_ID))
@@ -932,6 +946,7 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 		{
 			if (((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_INIT_ACK_CHUNK_ID) &&
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_DATA_CHUNK_ID) &&
+			    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_I_DATA_CHUNK_ID) &&
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_SACK_CHUNK_ID) &&
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_NR_SACK_CHUNK_ID) &&
 			    ((tvb_get_guint8(sctp_info->tvb[0],0)) != SCTP_FORWARD_TSN_CHUNK_ID))
@@ -956,9 +971,10 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 					info->ep2_chunk_count[idx]++;
 				info = add_chunk_count(&tmp_info.src, info,info->direction, idx);
 
-				if (((tvb_get_guint8(sctp_info->tvb[chunk_number],0)) == SCTP_DATA_CHUNK_ID))
+				if ((tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) ||
+				    (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_I_DATA_CHUNK_ID))
 					datachunk = TRUE;
-				if (((tvb_get_guint8(sctp_info->tvb[chunk_number],0)) == SCTP_FORWARD_TSN_CHUNK_ID))
+				if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_FORWARD_TSN_CHUNK_ID)
 					forwardchunk = TRUE;
 				if ((datachunk || forwardchunk) && tsn != NULL)
 				{
@@ -969,7 +985,11 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 					{
 						t_s_n = (guint8 *)g_malloc(16);
 						tvb_memcpy(sctp_info->tvb[chunk_number], (guint8 *)(t_s_n),0, 16);
-						length=tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET)-DATA_CHUNK_HEADER_LENGTH;
+						if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) {
+							length=tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET)-DATA_CHUNK_HEADER_LENGTH;
+						} else {
+							length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - I_DATA_CHUNK_HEADER_LENGTH;
+						}
 						info->n_data_chunks++;
 						info->n_data_bytes+=length;
 					}
@@ -1056,7 +1076,11 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 						{
 							if (datachunk)
 							{
-								length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET)-DATA_CHUNK_HEADER_LENGTH;
+								if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) {
+									length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - DATA_CHUNK_HEADER_LENGTH;
+								} else {
+									length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - I_DATA_CHUNK_HEADER_LENGTH;
+								}
 								info->n_data_chunks_ep2++;
 								info->n_data_bytes_ep2+=length;
 							}
@@ -1070,7 +1094,11 @@ packet(void *tapdata _U_, packet_info *pinfo, epan_dissect_t *edt _U_, const voi
 							info->max_tsn2 = tsnumber;
 							if (datachunk)
 							{
-								length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET)-DATA_CHUNK_HEADER_LENGTH;
+								if (tvb_get_guint8(sctp_info->tvb[chunk_number],0) == SCTP_DATA_CHUNK_ID) {
+									length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - DATA_CHUNK_HEADER_LENGTH;
+								} else {
+									length = tvb_get_ntohs(sctp_info->tvb[chunk_number], CHUNK_LENGTH_OFFSET) - I_DATA_CHUNK_HEADER_LENGTH;
+								}
 								info->n_data_chunks_ep2++;
 								info->n_data_bytes_ep2+=length;
 							}
diff --git a/ui/tap-sctp-analysis.h b/ui/tap-sctp-analysis.h
index b7fabd19db..18f0b86886 100644
--- a/ui/tap-sctp-analysis.h
+++ b/ui/tap-sctp-analysis.h
@@ -56,6 +56,7 @@ extern "C" {
 #define SCTP_SHUTDOWN_COMPLETE_CHUNK_ID 14
 #define SCTP_AUTH_CHUNK_ID		15
 #define SCTP_NR_SACK_CHUNK_ID		16
+#define SCTP_I_DATA_CHUNK_ID          0x40
 #define SCTP_ASCONF_ACK_CHUNK_ID      0x80
 #define SCTP_PKTDROP_CHUNK_ID	      0x81
 #define SCTP_RE_CONFIG_CHUNK_ID	      0x82
@@ -65,7 +66,7 @@ extern "C" {
 #define SCTP_IETF_EXT		      0xFF
 
 #define IS_SCTP_CHUNK_TYPE(t) \
-	(((t) <= 16) || ((t) == 0xC0) || ((t) == 0xC1) || ((t) == 0x80) || ((t) == 0x81))
+	(((t) <= 16) || ((t) == 0x40) || ((t) == 0xC0) || ((t) == 0xC1) || ((t) == 0x80) || ((t) == 0x81))
 
 #define CHUNK_TYPE_LENGTH	      1
 #define CHUNK_FLAGS_LENGTH	      1
@@ -99,11 +100,31 @@ extern "C" {
 #define DATA_CHUNK_STREAM_ID_LENGTH   2
 #define DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH 2
 #define DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH 4
+#define I_DATA_CHUNK_RESERVED_LENGTH 2
+#define I_DATA_CHUNK_MID_LENGTH 4
+#define I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH 4
+#define I_DATA_CHUNK_FSN_LENGTH 4
+#define I_DATA_CHUNK_RESERVED_OFFSET  (DATA_CHUNK_STREAM_ID_OFFSET + \
+                                       DATA_CHUNK_STREAM_ID_LENGTH)
+#define I_DATA_CHUNK_MID_OFFSET       (I_DATA_CHUNK_RESERVED_OFFSET + \
+                                       I_DATA_CHUNK_RESERVED_LENGTH)
+#define I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET (I_DATA_CHUNK_MID_OFFSET + \
+                                                 I_DATA_CHUNK_MID_LENGTH)
+#define I_DATA_CHUNK_FSN_OFFSET       (I_DATA_CHUNK_MID_OFFSET + \
+                                       I_DATA_CHUNK_MID_LENGTH)
+#define I_DATA_CHUNK_PAYLOAD_OFFSET   (I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_OFFSET + \
+                                       I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
 #define DATA_CHUNK_HEADER_LENGTH      (CHUNK_HEADER_LENGTH + \
 				       DATA_CHUNK_TSN_LENGTH + \
 				       DATA_CHUNK_STREAM_ID_LENGTH + \
 				       DATA_CHUNK_STREAM_SEQ_NUMBER_LENGTH + \
 				       DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
+#define I_DATA_CHUNK_HEADER_LENGTH    (CHUNK_HEADER_LENGTH + \
+                                       DATA_CHUNK_TSN_LENGTH + \
+                                       DATA_CHUNK_STREAM_ID_LENGTH + \
+                                       I_DATA_CHUNK_RESERVED_LENGTH + \
+                                       I_DATA_CHUNK_MID_LENGTH +\
+                                       I_DATA_CHUNK_PAYLOAD_PROTOCOL_ID_LENGTH)
 #define MAX_ADDRESS_LEN		       47
 
 #define SCTP_ABORT_CHUNK_T_BIT	      0x01
@@ -159,7 +180,8 @@ static const value_string chunk_type_values[] = {
 	{ SCTP_CWR_CHUNK_ID,		   "CWR" },
 	{ SCTP_SHUTDOWN_COMPLETE_CHUNK_ID, "SHUTDOWN_COMPLETE" },
 	{ SCTP_AUTH_CHUNK_ID,		   "AUTH" },
-	{ SCTP_NR_SACK_CHUNK_ID,	   "NR-SACK" },
+	{ SCTP_NR_SACK_CHUNK_ID,	   "NR_SACK" },
+	{ SCTP_I_DATA_CHUNK_ID,            "I_DATA" },
 	{ SCTP_ASCONF_ACK_CHUNK_ID,	   "ASCONF_ACK" },
 	{ SCTP_PKTDROP_CHUNK_ID,	   "PKTDROP" },
 	{ SCTP_RE_CONFIG_CHUNK_ID,	   "RE_CONFIG" },