[Josh Bailey <joshbailey@xxxxxxxxxx>]

Spec was incorrect, length field is only 10 bits.

Thanks,

--- ../tmp/ethereal-0.10.6/epan/dissectors/packet-ipdc.c        2004-08-12 
15:41
:57.000000000 -0700
+++ epan/dissectors/packet-ipdc.c       2004-10-22 08:57:29.000000000 
-0700
@@ -72,7 +72,10 @@
 static guint
 get_ipdc_pdu_len(tvbuff_t *tvb, int offset)
 {
-        return tvb_get_ntohs(tvb,offset+2)+4;
+       /* lower 10 bits only */
+       guint raw_len = (tvb_get_ntohs(tvb,offset+2) & 0x03FF);
+
+       return raw_len + 4;
 }

 static void
@@ -98,7 +101,7 @@

        gshort nr = tvb_get_guint8(tvb,0);
        gshort ns = tvb_get_guint8(tvb,1);
-       guint16 payload_len = (guint16) get_ipdc_pdu_len(tvb,0);
+       guint payload_len = get_ipdc_pdu_len(tvb,0);

         gshort protocol_id;
         gshort trans_id_size;
@@ -140,7 +143,7 @@

        /* IPDC tags present - display message code and trans. ID */
        protocol_id = tvb_get_guint8(tvb,4);
-               trans_id_size = TRANS_ID_SIZE_IPDC;
+       trans_id_size = TRANS_ID_SIZE_IPDC; /* tvb_get_guint8(tvb,5); */
                trans_id = tvb_get_ntohl(tvb,6);
                message_code = tvb_get_ntohs(tvb,6+trans_id_size);
                offset = 6 + trans_id_size + 2; /* past message_code */

--
Josh Bailey (joshbailey@xxxxxxxxxx)