path: root/epan/dissectors/packet-mtp3mg.c

/* packet-mtp3mg.c
 * Routines for Message Transfer Part Level 3 Management and Test dissection
 *
 * It is (hopefully) compliant to:
 *   ANSI T1.111.4-1996
 *   ITU-T Q.704 7/1996
 *   ITU-T Q.707 7/1996 and ANSI T1.111.7-1996 (for SLT message formats)
 *   portions of ITU-T Q.2210 7/1996 (for XCO/XCA message formats)
 *   GF 001-9001 (Chinese ITU variant)
 *   JT-Q704, JT-Q707v2, and NTT-Q704 (Japan)
 *
 *   Note that the division of the Japan SLS into the SLC and A/B bit is not
 *   done.
 *
 * Copyright 2003, Jeff Morriss <jeff.morriss.ws [AT] gmail.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * Copied from packet-mtp3.c
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/expert.h>

#include <wsutil/str_util.h>

#include "packet-mtp3.h"

void proto_register_mtp3mg(void);
void proto_reg_handoff_mtp3mg(void);

#define H0H1_LENGTH 1
#define H0_MASK     0x0f
#define H1_MASK     0xf0
#define H1_SHIFT    4

#define H0_CHM 0x01
#define H0_ECM 0x02
#define H0_FCM 0x03
#define H0_TFM 0x04
#define H0_RSM 0x05
#define H0_MIM 0x06     /* not used in Japan */
#define H0_TRM 0x07     /* not used in Japan */
#define H0_DLM 0x08     /* not used in Japan */
#define H0_UFC 0x0a     /* not used in Japan */
static const value_string h0_message_type_values[] = {
  { H0_CHM, "Changeover and changeback messages" },
  { H0_ECM, "Emergency changeover messages" },
  { H0_FCM, "Transfer-controlled and signalling route set congestion messages" },
  { H0_TFM, "Transfer prohibited-allowed-restricted messages" },
  { H0_RSM, "Signalling-route-set-test messages" },
  { H0_MIM, "Management inhibit messages" },
  { H0_TRM, "Traffic restart messages" },
  { H0_DLM, "Signalling-data-link-connection messages" },
  { H0_UFC, "User part flow control messages" },
  { 0,      NULL } };

#define TEST_H0_SLT 0x1
static const value_string test_h0_message_type_values[] = {
  { TEST_H0_SLT, "Test messages" },
  { 0,           NULL } };

#define CHM_H1_COO 0x01
#define CHM_H1_COA 0x02
#define CHM_H1_XCO 0x03
#define CHM_H1_XCA 0x04
#define CHM_H1_CBD 0x05
#define CHM_H1_CBA 0x06
static const value_string chm_h1_message_type_values[] = {
  { CHM_H1_COO, "Changeover-order signal" },
  { CHM_H1_COA, "Changeover-ack signal" },
  { CHM_H1_XCO, "Extended changeover-order signal" },
  { CHM_H1_XCA, "Extended changeover-ack signal" },
  { CHM_H1_CBD, "Changeback-declaration signal" },
  { CHM_H1_CBA, "Changeback-ack signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string chm_h1_message_type_acro_values[] = {
  { CHM_H1_COO, "COO" },
  { CHM_H1_COA, "COA" },
  { CHM_H1_XCO, "XCO" },
  { CHM_H1_XCA, "XCA" },
  { CHM_H1_CBD, "CBD" },
  { CHM_H1_CBA, "CBA" },
  { 0,          NULL } };

#define ECM_H1_ECO 0x01
#define ECM_H1_ECA 0x02
static const value_string ecm_h1_message_type_values[] = {
  { ECM_H1_ECO, "Emergency-changeover-order signal" },
  { ECM_H1_ECA, "Emergency-changeover-ack signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string ecm_h1_message_type_acro_values[] = {
  { ECM_H1_ECO, "ECO" },
  { ECM_H1_ECA, "ECA" },
  { 0,          NULL } };

#define FCM_H1_RCT 0x01
#define FCM_H1_TFC 0x02
static const value_string fcm_h1_message_type_values[] = {
  { FCM_H1_RCT, "Signalling-route-set-congestion-test signal" },
  { FCM_H1_TFC, "Transfer-controlled signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string fcm_h1_message_type_acro_values[] = {
  { FCM_H1_RCT, "RCT" },
  { FCM_H1_TFC, "TFC" },
  { 0,          NULL } };

#define TFM_H1_TFP 0x01
#define TFM_H1_TCP 0x02 /* ANSI only */
#define TFM_H1_TFR 0x03
#define TFM_H1_TCR 0x04 /* ANSI only */
#define TFM_H1_TFA 0x05
#define TFM_H1_TCA 0x06 /* ANSI only */
static const value_string tfm_h1_message_type_values[] = {
  { TFM_H1_TFP, "Transfer-prohibited signal" },
  { TFM_H1_TCP, "Transfer-cluster-prohibited signal (ANSI only)" },
  { TFM_H1_TFR, "Transfer-restricted signal" },
  { TFM_H1_TCR, "Transfer-cluster-restricted signal (ANSI only)" },
  { TFM_H1_TFA, "Transfer-allowed signal" },
  { TFM_H1_TCA, "Transfer-cluster-allowed signal (ANSI only)" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string tfm_h1_message_type_acro_values[] = {
  { TFM_H1_TFP, "TFP" },
  { TFM_H1_TCP, "TCP" },
  { TFM_H1_TFR, "TFR" },
  { TFM_H1_TCR, "TCR" },
  { TFM_H1_TFA, "TFA" },
  { TFM_H1_TCA, "TCA" },
  { 0,          NULL } };

#define RSM_H1_RST 0x01
#define RSM_H1_RSR 0x02
#define RSM_H1_RCP 0x03 /* ANSI only */
#define RSM_H1_RCR 0x04 /* ANSI only */
static const value_string rsm_h1_message_type_values[] = {
  { RSM_H1_RST, "Signalling-route-set-test prohibited signal" },
  { RSM_H1_RSR, "Signalling-route-set-test restricted signal" },
  { RSM_H1_RCP, "Signalling-route-set-test cluster-prohibited signal (ANSI only)" },
  { RSM_H1_RCR, "Signalling-route-set-test cluster-restricted signal (ANSI only)" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string rsm_h1_message_type_acro_values[] = {
  { RSM_H1_RST, "RST" },
  { RSM_H1_RSR, "RSR" },
  { RSM_H1_RCP, "RCP" },
  { RSM_H1_RCR, "RCR" },
  { 0,          NULL } };

#define MIM_H1_LIN 0x01
#define MIM_H1_LUN 0x02
#define MIM_H1_LIA 0x03
#define MIM_H1_LUA 0x04
#define MIM_H1_LID 0x05
#define MIM_H1_LFU 0x06
#define MIM_H1_LLT 0x07 /* LLI in ANSI */
#define MIM_H1_LRT 0x08 /* LRI in ANSI */
static const value_string mim_h1_message_type_values[] = {
  { MIM_H1_LIN, "Link inhibit signal" },
  { MIM_H1_LUN, "Link uninhibit signal" },
  { MIM_H1_LIA, "Link inhibit ack signal" },
  { MIM_H1_LUA, "Link uninhibit ack signal" },
  { MIM_H1_LID, "Link inhibit denied signal" },
  { MIM_H1_LFU, "Link forced uninhibit signal" },
  { MIM_H1_LLT, "Link local inhibit test signal" },
  { MIM_H1_LRT, "Link remote inhibit test signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string mim_h1_message_type_acro_values[] = {
  { MIM_H1_LIN, "LIN" },
  { MIM_H1_LUN, "LUN" },
  { MIM_H1_LIA, "LIA" },
  { MIM_H1_LUA, "LUA" },
  { MIM_H1_LID, "LID" },
  { MIM_H1_LFU, "LFU" },
  { MIM_H1_LLT, "LLT (LLI)" },
  { MIM_H1_LRT, "LRT (LRI)" },
  { 0,          NULL } };

#define TRM_H1_TRA 0x01
#define TRM_H1_TRW 0x02 /* ANSI only */
static const value_string trm_h1_message_type_values[] = {
  { TRM_H1_TRA, "Traffic-restart-allowed signal" },
  { TRM_H1_TRW, "Traffic-restart-waiting signal (ANSI only)" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string trm_h1_message_type_acro_values[] = {
  { TRM_H1_TRA, "TRA" },
  { TRM_H1_TRW, "TRW" },
  { 0,          NULL } };

#define DLM_H1_DLC 0x01
#define DLM_H1_CSS 0x02
#define DLM_H1_CNS 0x03
#define DLM_H1_CNP 0x04
static const value_string dlm_h1_message_type_values[] = {
  { DLM_H1_DLC, "Signalling-data-link-connection-order signal" },
  { DLM_H1_CSS, "Connection-successful signal" },
  { DLM_H1_CNS, "Connection-not-successful signal" },
  { DLM_H1_CNP, "Connection-not-possible signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string dlm_h1_message_type_acro_values[] = {
  { DLM_H1_DLC, "DLC" },
  { DLM_H1_CSS, "CSS" },
  { DLM_H1_CNS, "CNS" },
  { DLM_H1_CNP, "CNP" },
  { 0,          NULL } };

#define UFC_H1_UPU 0x01
static const value_string ufc_h1_message_type_values[] = {
  { UFC_H1_UPU, "User part unavailable signal" },
  { 0,          NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string ufc_h1_message_type_acro_values[] = {
  { UFC_H1_UPU, "UPU" },
  { 0,          NULL } };

static const value_string upu_cause_values[] = {
  { 0x0, "Unknown" },
  { 0x1, "Unequipped remote user" },
  { 0x2, "Inaccessible remote user" },
  { 0,   NULL } };

#define TEST_H1_SLTM 0x1
#define TEST_H1_SLTA 0x2
static const value_string test_h1_message_type_values[] = {
  { TEST_H1_SLTM, "Signalling link test message" },
  { TEST_H1_SLTA, "Signalling link test acknowledgement message" },
  { 0,            NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string test_h1_message_type_acro_values[] = {
  { TEST_H1_SLTM, "SLTM" },
  { TEST_H1_SLTA, "SLTA" },
  { 0,            NULL } };

#define JAPAN_TEST_SRT 0x23
#define JAPAN_TEST_SRA 0x84
static const value_string japan_test_message_type_values[] = {
  { JAPAN_TEST_SRT, "Signalling routing test message" },
  { JAPAN_TEST_SRA, "Signalling routing test acknowledgement message" },
  { 0,              NULL } };

/* Same as above but in acronym form (for the Info column) */
static const value_string japan_test_message_type_acro_values[] = {
  { JAPAN_TEST_SRT, "SRT" },
  { JAPAN_TEST_SRA, "SRA" },
  { 0,              NULL } };

#define ANSI_COO_LENGTH    2
#define ANSI_COO_SLC_MASK  0x000f
#define ANSI_COO_FSN_MASK  0x07f0
#define ITU_COO_LENGTH     1
#define ITU_COO_FSN_MASK   0x7f
#define ANSI_XCO_LENGTH    4
#define ANSI_XCO_SLC_MASK  0x0000000f
#define ANSI_XCO_FSN_MASK  0x0ffffff0
#define ITU_XCO_LENGTH     3
#define ANSI_CBD_LENGTH    2
#define ANSI_CBD_SLC_MASK  0x000f
#define ANSI_CBD_CBC_MASK  0x0ff0
#define ITU_CBD_LENGTH     1
#define JAPAN_CBD_CBC_MASK 0x3

#define ANSI_ECO_LENGTH   1
#define ANSI_ECO_SLC_MASK 0x0f

#define ANSI_TFC_STATUS_LENGTH       1
#define ANSI_TFC_STATUS_OFFSET       ANSI_PC_LENGTH
#define ANSI_TFC_STATUS_MASK         0x03
#define ITU_TFC_STATUS_LENGTH        ITU_PC_LENGTH
#define ITU_TFC_STATUS_MASK          0xc000
#define JAPAN_TFC_SPARE_OFFSET        0
#define JAPAN_TFC_SPARE_LENGTH        1
#define JAPAN_TFC_APC_OFFSET          JAPAN_TFC_SPARE_LENGTH
#define JAPAN_TFC_STATUS_OFFSET       (JAPAN_TFC_SPARE_LENGTH + JAPAN_PC_LENGTH)
#define JAPAN_TFC_STATUS_LENGTH       1
#define JAPAN_TFC_STATUS_MASK         0x03
#define JAPAN_TFC_STATUS_SPARE_MASK   0xfc

#define JAPAN_TFM_COUNT_OFFSET 0
#define JAPAN_TFM_COUNT_LENGTH 1

#define ANSI_MIM_LENGTH   1
#define ANSI_MIM_SLC_MASK 0x0f

#define ANSI_DLC_LENGTH    3
#define ANSI_DLC_SLC_MASK  0x00000f
#define ANSI_DLC_LINK_MASK 0x03fff0
#define ITU_DLC_LENGTH     2
#define ITU_DLC_LINK_MASK  0x0fff

#define ANSI_UPU_USER_OFFSET ANSI_PC_LENGTH
#define UPU_USER_LENGTH      1
#define UPU_USER_MASK        0x0f
#define UPU_CAUSE_MASK       0xf0
#define ITU_UPU_USER_OFFSET  ITU_PC_LENGTH

#define TEST_LENGTH         1
#define TEST_LENGTH_MASK    0xf0
#define TEST_LENGTH_SHIFT   4
#define TEST_PATTERN_OFFSET TEST_LENGTH
#define ANSI_TEST_SLC_MASK  0x0f

#define JAPAN_SPARE_LENGTH 1
#define JAPAN_H0H1_OFFSET JAPAN_SPARE_LENGTH

#define JAPAN_TEST_SPARE_OFFSET   JAPAN_SPARE_LENGTH + H0H1_LENGTH
#define JAPAN_TEST_SPARE_LENGTH   1
#define JAPAN_TEST_PATTERN_OFFSET (JAPAN_TEST_SPARE_OFFSET + JAPAN_TEST_SPARE_LENGTH)
#define JAPAN_TEST_PATTERN_LENGTH 2
#define JAPAN_TEST_PATTERN 0x7711


/* This list is slightly different from that in packet-mtp3.c */
static const value_string service_indicator_code_vals[] = {
        { 0x0,  "Spare" },
        { 0x1,  "Spare"},
        { 0x2,  "Spare" },
        { 0x3,  "SCCP" },
        { 0x4,  "TUP" },
        { 0x5,  "ISUP" },
        { 0x6,  "DUP (call and circuit related messages)" },
        { 0x7,  "DUP (facility registration and cancellation message)" },
        { 0x8,  "MTP testing user part" },
        { 0x9,  "ISUP-b" },
        { 0xa,  "ISUP-s" },
        { 0xb,  "Spare" },
        { 0xc,  "Spare" },
        { 0xd,  "Spare" },
        { 0xe,  "Spare" },
        { 0xf,  "Spare" },
        { 0,    NULL }
};

/* Initialize the protocol and registered fields */
static int proto_mtp3mg;
static int hf_mtp3mg_h0;
static int hf_mtp3mg_chm_h1;
static int hf_mtp3mg_ecm_h1;
static int hf_mtp3mg_fcm_h1;
static int hf_mtp3mg_tfm_h1;
static int hf_mtp3mg_rsm_h1;
static int hf_mtp3mg_mim_h1;
static int hf_mtp3mg_trm_h1;
static int hf_mtp3mg_dlm_h1;
static int hf_mtp3mg_ufc_h1;
static int hf_mtp3mg_coo_ansi_slc;
static int hf_mtp3mg_coo_ansi_fsn;
static int hf_mtp3mg_coo_itu_fsn;
static int hf_mtp3mg_xco_ansi_slc;
static int hf_mtp3mg_xco_ansi_fsn;
static int hf_mtp3mg_xco_itu_fsn;
static int hf_mtp3mg_cbd_ansi_slc;
static int hf_mtp3mg_cbd_ansi_cbc;
static int hf_mtp3mg_cbd_itu_cbc;
static int hf_mtp3mg_cbd_japan_cbc;
static int hf_mtp3mg_eco_ansi_slc;
static int hf_mtp3mg_ansi_apc;
static int hf_mtp3mg_apc_member;
static int hf_mtp3mg_apc_cluster;
static int hf_mtp3mg_apc_network;
static int hf_mtp3mg_tfc_ansi_status;
static int hf_mtp3mg_itu_apc;
static int hf_mtp3mg_tfc_itu_status;
static int hf_mtp3mg_chinese_apc;
static int hf_mtp3mg_tfc_japan_spare;
static int hf_mtp3mg_japan_apc;
static int hf_mtp3mg_tfc_japan_status;
static int hf_mtp3mg_tfc_japan_status_spare;
static int hf_mtp3mg_tfm_japan_count;
static int hf_mtp3mg_tfm_japan_spare;
static int hf_mtp3mg_rsm_japan_count;
static int hf_mtp3mg_rsm_japan_spare;
static int hf_mtp3mg_mim_ansi_slc;
static int hf_mtp3mg_dlc_ansi_slc;
static int hf_mtp3mg_dlc_ansi_link;
static int hf_mtp3mg_dlc_itu_link;
static int hf_mtp3mg_upu_user;
static int hf_mtp3mg_upu_cause;
static int hf_mtp3test_h0;
static int hf_mtp3mg_test_h1;
static int hf_mtp3mg_test_ansi_slc;
static int hf_mtp3mg_test_length;
static int hf_mtp3mg_japan_test;
static int hf_mtp3mg_japan_test_spare;
static int hf_mtp3mg_japan_test_pattern;
static int hf_mtp3mg_japan_spare;
static int hf_mtp3mg_test_pattern;

/* Initialize the subtree pointers */
static int ett_mtp3mg;
static int ett_mtp3mg_fcm_apc;
static int ett_mtp3mg_tfm_apc;
static int ett_mtp3mg_rsm_apc;
static int ett_mtp3mg_upu_apc;

static expert_field ei_mtp3mg_unknown_message;

static dissector_handle_t mtp3mg_handle;

static void
dissect_mtp3mg_unknown_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    uint8_t message_length;

    message_length = tvb_captured_length(tvb);
    proto_tree_add_expert_format(tree, pinfo, &ei_mtp3mg_unknown_message, tvb, 0, message_length,
                        "Unknown message (%u byte%s)", message_length,
                        plurality(message_length, "", "s"));
}

static void
dissect_mtp3mg_chm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, chm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case CHM_H1_COO:
    case CHM_H1_COA:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_coo_ansi_slc, tvb, 0,
                                ANSI_COO_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_coo_ansi_fsn, tvb, 0,
                                ANSI_COO_LENGTH, ENC_LITTLE_ENDIAN);
        } else /* ITU_STANDARD, CHINESE_ITU_STANDARD, and JAPAN_STANDARD */ {
            proto_tree_add_item(tree, hf_mtp3mg_coo_itu_fsn, tvb, 0,
                                ITU_COO_LENGTH, ENC_LITTLE_ENDIAN);
        }
        break;

    case CHM_H1_XCO:
    case CHM_H1_XCA:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_xco_ansi_slc, tvb, 0,
                                ANSI_XCO_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_xco_ansi_fsn, tvb, 0,
                                ANSI_XCO_LENGTH, ENC_LITTLE_ENDIAN);
        } else /* ITU_STANDARD, CHINESE_ITU_STANDARD, and JAPAN_STANDARD */ {
            proto_tree_add_item(tree, hf_mtp3mg_xco_itu_fsn, tvb, 0,
                                ITU_XCO_LENGTH, ENC_LITTLE_ENDIAN);
        }
        break;

    case CHM_H1_CBD:
    case CHM_H1_CBA:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_cbd_ansi_slc, tvb, 0,
                                ANSI_CBD_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_cbd_ansi_cbc, tvb, 0,
                                ANSI_CBD_LENGTH, ENC_LITTLE_ENDIAN);
        } else if (mtp3_standard == JAPAN_STANDARD) {
            proto_tree_add_item(tree, hf_mtp3mg_cbd_japan_cbc, tvb, 0,
                                ITU_CBD_LENGTH, ENC_LITTLE_ENDIAN);
        } else /* ITU_STANDARD and CHINESE_ITU_STANDARD */ {
            proto_tree_add_item(tree, hf_mtp3mg_cbd_itu_cbc, tvb, 0,
                                ITU_CBD_LENGTH, ENC_LITTLE_ENDIAN);
        }
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
  }
}

static void
dissect_mtp3mg_ecm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, ecm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case ECM_H1_ECO:
    case ECM_H1_ECA:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_eco_ansi_slc, tvb, 0,
                                ANSI_ECO_LENGTH, ENC_LITTLE_ENDIAN);
        }
        /* else: nothing to dissect */
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_fcm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    proto_item *apc_item;

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, fcm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case FCM_H1_RCT:
        /* nothing to dissect */
        break;

    case FCM_H1_TFC:
        if (mtp3_standard == ITU_STANDARD)
        {

            apc_item = proto_tree_add_item(tree, hf_mtp3mg_itu_apc, tvb, 0,
                                           ITU_PC_LENGTH, ENC_LITTLE_ENDIAN);

            if (mtp3_pc_structured()) {
                uint32_t apc;

                apc = tvb_get_letohs(tvb, 0) & ITU_PC_MASK;
                proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
            }

            /* Congestion level is a national option */
            proto_tree_add_item(tree, hf_mtp3mg_tfc_itu_status, tvb, 0,
                                ITU_TFC_STATUS_LENGTH, ENC_LITTLE_ENDIAN);



        } else if (mtp3_standard == JAPAN_STANDARD) {

            proto_tree_add_item(tree, hf_mtp3mg_tfc_japan_spare, tvb,
                                JAPAN_TFC_SPARE_OFFSET,
                                JAPAN_TFC_SPARE_LENGTH, ENC_LITTLE_ENDIAN);

            apc_item = proto_tree_add_item(tree, hf_mtp3mg_japan_apc, tvb,
                                           JAPAN_TFC_APC_OFFSET,
                                           JAPAN_PC_LENGTH, ENC_LITTLE_ENDIAN);
            if (mtp3_pc_structured()) {
                uint32_t apc;

                apc = tvb_get_letohs(tvb, JAPAN_TFC_APC_OFFSET);
                proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
            }

            proto_tree_add_item(tree, hf_mtp3mg_tfc_japan_status, tvb,
                                JAPAN_TFC_STATUS_OFFSET,
                                JAPAN_TFC_STATUS_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_tfc_japan_status_spare, tvb,
                                JAPAN_TFC_STATUS_OFFSET,
                                JAPAN_TFC_STATUS_LENGTH, ENC_LITTLE_ENDIAN);

        } else /* ANSI_STANDARD and CHINESE_ITU_STANDARD */ {

            int hf_apc_string;

            if (mtp3_standard == ANSI_STANDARD) {

                hf_apc_string = hf_mtp3mg_ansi_apc;

            } else /* CHINESE_ITU_STANDARD */ {

                hf_apc_string = hf_mtp3mg_chinese_apc;
            }

            dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_fcm_apc,
                                  hf_apc_string, hf_mtp3mg_apc_network,
                                  hf_mtp3mg_apc_cluster,
                                  hf_mtp3mg_apc_member, 0, 0);

            proto_tree_add_item(tree, hf_mtp3mg_tfc_ansi_status, tvb,
                                ANSI_TFC_STATUS_OFFSET, ANSI_TFC_STATUS_LENGTH,
                                ENC_LITTLE_ENDIAN);

        }
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_tfm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    proto_item *apc_item;

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, tfm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case TFM_H1_TFP:
    case TFM_H1_TCP:
    case TFM_H1_TFR:
    case TFM_H1_TCR:
    case TFM_H1_TFA:
    case TFM_H1_TCA:
        if (mtp3_standard == ANSI_STANDARD) {
            dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_tfm_apc,
                                  hf_mtp3mg_ansi_apc,
                                  hf_mtp3mg_apc_network,
                                  hf_mtp3mg_apc_cluster,
                                  hf_mtp3mg_apc_member, 0, 0);

        } else if (mtp3_standard == JAPAN_STANDARD) {
            uint8_t count, i;
            uint32_t offset;

            if (h1 == TFM_H1_TCP || h1 == TFM_H1_TCR || h1 == TFM_H1_TCA
                || h1 == TFM_H1_TFR)
                dissect_mtp3mg_unknown_message(tvb, pinfo, tree);

            proto_tree_add_item(tree, hf_mtp3mg_tfm_japan_count, tvb,
                                JAPAN_TFM_COUNT_OFFSET,
                                JAPAN_TFM_COUNT_LENGTH, ENC_LITTLE_ENDIAN);

            count = tvb_get_uint8(tvb, JAPAN_TFM_COUNT_OFFSET);
            offset = JAPAN_TFM_COUNT_LENGTH;
            for (i = 0; i < count; i++)
            {
                apc_item = proto_tree_add_item(tree, hf_mtp3mg_japan_apc, tvb,
                                    offset, JAPAN_PC_LENGTH, ENC_LITTLE_ENDIAN);

                if (mtp3_pc_structured()) {
                    uint32_t apc;

                    apc = tvb_get_letohs(tvb, offset);
                    proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
                }

                offset += JAPAN_PC_LENGTH;
                proto_tree_add_item(tree, hf_mtp3mg_tfm_japan_spare, tvb,
                                    offset, JAPAN_PC_LENGTH, ENC_LITTLE_ENDIAN);
                offset += JAPAN_PC_LENGTH;
            }
        } else /* ITU_STANDARD and CHINESE_ITU_STANDARD */ {

            if (h1 == TFM_H1_TCP || h1 == TFM_H1_TCR || h1 == TFM_H1_TCA)
                dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
            else if (mtp3_standard == ITU_STANDARD)
            {
                apc_item = proto_tree_add_item(tree, hf_mtp3mg_itu_apc,
                                               tvb, 0, ITU_PC_LENGTH, ENC_LITTLE_ENDIAN);

                if (mtp3_pc_structured()) {
                    uint32_t apc;

                    apc = tvb_get_letohs(tvb, 0) & ITU_PC_MASK;
                    proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
                }
            }
            else if (mtp3_standard == CHINESE_ITU_STANDARD)
                dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_tfm_apc,
                                      hf_mtp3mg_chinese_apc,
                                      hf_mtp3mg_apc_network,
                                      hf_mtp3mg_apc_cluster,
                                      hf_mtp3mg_apc_member, 0, 0);
        }
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_rsm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    proto_item *apc_item;

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, rsm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case RSM_H1_RST:
    case RSM_H1_RSR:
    case RSM_H1_RCP:
    case RSM_H1_RCR:
        if (mtp3_standard == ANSI_STANDARD) {
            dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_rsm_apc,
                                  hf_mtp3mg_ansi_apc,
                                  hf_mtp3mg_apc_network,
                                  hf_mtp3mg_apc_cluster,
                                  hf_mtp3mg_apc_member, 0, 0);

        } else if (mtp3_standard == JAPAN_STANDARD) {
            if (h1 == RSM_H1_RST) {
                uint32_t offset;
                uint8_t count, i;

                proto_tree_add_item(tree, hf_mtp3mg_rsm_japan_count, tvb,
                                    JAPAN_TFM_COUNT_OFFSET,
                                    JAPAN_TFM_COUNT_LENGTH, ENC_LITTLE_ENDIAN);

                count = tvb_get_uint8(tvb, JAPAN_TFM_COUNT_OFFSET);
                offset = JAPAN_TFM_COUNT_LENGTH;
                for (i = 0; i < count; i++) {
                    apc_item = proto_tree_add_item(tree,
                                                   hf_mtp3mg_japan_apc,
                                                   tvb, offset,
                                                   JAPAN_PC_LENGTH,
                                                   ENC_LITTLE_ENDIAN);
                    if (mtp3_pc_structured()) {
                        uint32_t apc;

                        apc = tvb_get_letohs(tvb, 0);
                        proto_item_append_text(apc_item, " (%s)",
                                               mtp3_pc_to_str(apc));
                    }
                    offset += JAPAN_PC_LENGTH;
                    proto_tree_add_item(tree, hf_mtp3mg_rsm_japan_spare, tvb,
                                        offset, JAPAN_PC_LENGTH,
                                        ENC_LITTLE_ENDIAN);
                    offset += JAPAN_PC_LENGTH;
                }
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, tree);

        } else /* ITU_STANDARD and CHINESE_ITU_STANDARD */ {

            if (h1 == RSM_H1_RST || h1 == RSM_H1_RSR) {
                if (mtp3_standard == ITU_STANDARD) {
                    apc_item = proto_tree_add_item(tree, hf_mtp3mg_itu_apc,
                                                   tvb, 0, ITU_PC_LENGTH,
                                                   ENC_LITTLE_ENDIAN);
                    if (mtp3_pc_structured()) {
                        uint32_t apc;

                        apc = tvb_get_letohs(tvb, 0) & ITU_PC_MASK;
                        proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
                    }
                }
                else /* CHINESE_ITU_STANDARD */
                    dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_rsm_apc,
                                          hf_mtp3mg_chinese_apc,
                                          hf_mtp3mg_apc_network,
                                          hf_mtp3mg_apc_cluster,
                                          hf_mtp3mg_apc_member, 0, 0);
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
        }
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_mim(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, mim_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case MIM_H1_LIN:
    case MIM_H1_LUN:
    case MIM_H1_LIA:
    case MIM_H1_LUA:
    case MIM_H1_LID:
    case MIM_H1_LFU:
    case MIM_H1_LLT:
    case MIM_H1_LRT:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_mim_ansi_slc, tvb, 0,
                                ANSI_MIM_LENGTH, ENC_LITTLE_ENDIAN);
        }
        /* else: nothing to dissect */
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_trm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, trm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case TRM_H1_TRA:
        /* nothing to dissect */
        break;
    case TRM_H1_TRW:
        if (mtp3_standard != ANSI_STANDARD)
            dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
        /* else: nothing to dissect */
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_dlm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, dlm_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case DLM_H1_DLC:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_dlc_ansi_slc, tvb, 0,
                                ANSI_DLC_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_dlc_ansi_link, tvb, 0,
                                ANSI_DLC_LENGTH, ENC_LITTLE_ENDIAN);
        } else /* ITU_STANDARD and CHINESE_ITU_STANDARD */ {
            proto_tree_add_item(tree, hf_mtp3mg_dlc_itu_link, tvb, 0,
                                ITU_DLC_LENGTH, ENC_LITTLE_ENDIAN);
        }
        break;
    case DLM_H1_CSS:
    case DLM_H1_CNS:
    case DLM_H1_CNP:
        /* nothing to dissect */
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_ufc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    proto_item *apc_item;

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, ufc_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case UFC_H1_UPU:
        if (mtp3_standard == ANSI_STANDARD
            || mtp3_standard == CHINESE_ITU_STANDARD) {
            int hf_apc;

            if (mtp3_standard == ANSI_STANDARD)
                hf_apc = hf_mtp3mg_ansi_apc;
            else /* CHINESE_ITU_STANDARD */
                hf_apc = hf_mtp3mg_chinese_apc;

            dissect_mtp3_3byte_pc(tvb, 0, tree, ett_mtp3mg_upu_apc, hf_apc,
                                  hf_mtp3mg_apc_network,
                                  hf_mtp3mg_apc_cluster,
                                  hf_mtp3mg_apc_member, 0, 0);

            proto_tree_add_item(tree, hf_mtp3mg_upu_user, tvb,
                                ANSI_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_upu_cause, tvb,
                                ANSI_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
        } else if (mtp3_standard == ITU_STANDARD) {

            apc_item = proto_tree_add_item(tree, hf_mtp3mg_itu_apc, tvb, 0,
                                           ITU_PC_LENGTH, ENC_LITTLE_ENDIAN);
            if (mtp3_pc_structured()) {
                uint32_t apc;

                apc = tvb_get_letohs(tvb, 0) & ITU_PC_MASK;
                proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
            }

            proto_tree_add_item(tree, hf_mtp3mg_upu_user, tvb,
                                ITU_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_upu_cause, tvb,
                                ITU_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
        } else { /* JAPAN_STANDARD */

            apc_item = proto_tree_add_item(tree, hf_mtp3mg_japan_apc, tvb,
                                           0, JAPAN_PC_LENGTH,
                                           ENC_LITTLE_ENDIAN);
            if (mtp3_pc_structured()) {
                uint32_t apc;

                apc = tvb_get_letohs(tvb, 0);
                proto_item_append_text(apc_item, " (%s)", mtp3_pc_to_str(apc));
            }

            proto_tree_add_item(tree, hf_mtp3mg_upu_user, tvb,
                                ITU_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_mtp3mg_upu_cause, tvb,
                                ITU_UPU_USER_OFFSET, UPU_USER_LENGTH, ENC_LITTLE_ENDIAN);
        }
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static void
dissect_mtp3mg_test(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                   uint8_t h1)
{
    uint8_t length;

    col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_str_const(h1, test_h1_message_type_acro_values, "Unknown"));

    switch (h1)
    {
    case TEST_H1_SLTM:
    case TEST_H1_SLTA:
        if (mtp3_standard == ANSI_STANDARD)
        {
            proto_tree_add_item(tree, hf_mtp3mg_test_ansi_slc, tvb, 0,
                                TEST_LENGTH, ENC_LITTLE_ENDIAN);
        }

        proto_tree_add_item(tree, hf_mtp3mg_test_length, tvb, 0, TEST_LENGTH,
                            ENC_LITTLE_ENDIAN);

        length = tvb_get_uint8(tvb, 0) >> TEST_LENGTH_SHIFT;
        proto_tree_add_item(tree, hf_mtp3mg_test_pattern, tvb, TEST_PATTERN_OFFSET, length, ENC_NA);
        break;

    default:
        dissect_mtp3mg_unknown_message(tvb, pinfo, tree);
    }
}

static int
dissect_mtp3mg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{

    uint8_t h0, h1;
    tvbuff_t *payload_tvb;

    /* Set up structures needed to add the protocol subtree and manage it */
    proto_item *mtp3mg_item;
    proto_tree *mtp3mg_tree;

    /* Make entries in Protocol column on summary display */
    switch(mtp3_standard) {
    case ITU_STANDARD:
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "MTP3MG (Int. ITU)");
        break;
    case ANSI_STANDARD:
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "MTP3MG (ANSI)");
        break;
    case CHINESE_ITU_STANDARD:
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "MTP3MG (Chin. ITU)");
        break;
    case JAPAN_STANDARD:
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "MTP3MG (Japan)");
        break;
    };

        /* create display subtree for the protocol */
        mtp3mg_item = proto_tree_add_item(tree, proto_mtp3mg, tvb, 0, -1, ENC_NA);
        mtp3mg_tree = proto_item_add_subtree(mtp3mg_item, ett_mtp3mg);

    /*
     *  Dissect the message
     */
    if(pinfo->match_uint == MTP_SI_MTN || /* ITU */
       pinfo->match_uint == MTP_SI_MTNS)  /* ANSI */
    {   /* Test messages */

        if (mtp3_standard == JAPAN_STANDARD)
        {
            uint8_t h0h1;
            uint16_t test_pattern;
            proto_item *pattern_item;

            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_japan_spare, tvb, 0,
                                JAPAN_SPARE_LENGTH, ENC_LITTLE_ENDIAN);

            h0h1 = tvb_get_uint8(tvb, JAPAN_H0H1_OFFSET);

            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_japan_test, tvb,
                                JAPAN_SPARE_LENGTH, H0H1_LENGTH, ENC_LITTLE_ENDIAN);

            col_add_fstr(pinfo->cinfo, COL_INFO, "%s ",
                         val_to_str_const(h0h1, japan_test_message_type_acro_values, "Unknown"));

            switch (h0h1)
            {
            case JAPAN_TEST_SRT:
            case JAPAN_TEST_SRA:
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_japan_test_spare,
                                    tvb, JAPAN_TEST_SPARE_OFFSET,
                                    JAPAN_TEST_SPARE_LENGTH, ENC_LITTLE_ENDIAN);

                test_pattern = tvb_get_letohs(tvb, JAPAN_TEST_PATTERN_OFFSET);
                pattern_item = proto_tree_add_item(mtp3mg_tree,
                                                   hf_mtp3mg_japan_test_pattern,
                                                   tvb,
                                                   JAPAN_TEST_PATTERN_OFFSET,
                                                   JAPAN_TEST_PATTERN_LENGTH,
                                                   ENC_LITTLE_ENDIAN);
                proto_item_append_text(pattern_item, " (%s)",
                                       test_pattern == JAPAN_TEST_PATTERN
                                       ? "correct" : "incorrect");
                break;

            default:
                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            }

        } else { /* not JAPAN */
            proto_tree_add_item(mtp3mg_tree, hf_mtp3test_h0, tvb, 0, H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            /* H1 is added below */

            h0 = tvb_get_uint8(tvb, 0) & H0_MASK;
            h1 = (tvb_get_uint8(tvb, 0) & H1_MASK) >> H1_SHIFT;

            payload_tvb = tvb_new_subset_remaining(tvb, H0H1_LENGTH);

            switch (h0)
            {
            case TEST_H0_SLT:
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_test_h1, tvb, 0,
                                    H0H1_LENGTH, ENC_LITTLE_ENDIAN);
                dissect_mtp3mg_test(payload_tvb, pinfo, mtp3mg_tree, h1);
                break;

            default:
                col_set_str(pinfo->cinfo, COL_INFO, "Unknown ");

                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            } /* switch */

        }

    } else {    /* Real management messages */


        if (mtp3_standard == JAPAN_STANDARD)
        {
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_japan_spare, tvb, 0,
                                JAPAN_SPARE_LENGTH, ENC_LITTLE_ENDIAN);

            /*  Get a tvb w/o the spare byte--it makes for less code below */
            tvb = tvb_new_subset_remaining(tvb, JAPAN_SPARE_LENGTH);
        }

        proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_h0, tvb, 0, H0H1_LENGTH,
                            ENC_LITTLE_ENDIAN);
        /* H1 is added below */

        h0 = tvb_get_uint8(tvb, 0) & H0_MASK;
        h1 = (tvb_get_uint8(tvb, 0) & H1_MASK) >> H1_SHIFT;

        payload_tvb = tvb_new_subset_remaining(tvb, H0H1_LENGTH);

        switch (h0)
        {
        case H0_CHM:
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_chm_h1, tvb, 0,
                                H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            dissect_mtp3mg_chm(payload_tvb, pinfo, mtp3mg_tree, h1);
            break;
        case H0_ECM:
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_ecm_h1, tvb, 0,
                                H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            dissect_mtp3mg_ecm(payload_tvb, pinfo, mtp3mg_tree, h1);
            break;
        case H0_FCM:
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_fcm_h1, tvb, 0,
                                H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            dissect_mtp3mg_fcm(payload_tvb, pinfo, mtp3mg_tree, h1);
            break;
        case H0_TFM:
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_tfm_h1, tvb, 0,
                                H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            dissect_mtp3mg_tfm(payload_tvb, pinfo, mtp3mg_tree, h1);
            break;
        case H0_RSM:
            proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_rsm_h1, tvb, 0,
                                H0H1_LENGTH, ENC_LITTLE_ENDIAN);
            dissect_mtp3mg_rsm(payload_tvb, pinfo, mtp3mg_tree, h1);
            break;
        case H0_MIM:
            if (mtp3_standard != JAPAN_STANDARD)
            {
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_mim_h1, tvb, 0,
                                    H0H1_LENGTH, ENC_LITTLE_ENDIAN);
                dissect_mtp3mg_mim(payload_tvb, pinfo, mtp3mg_tree, h1);
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            break;
        case H0_TRM:
            if (mtp3_standard != JAPAN_STANDARD)
            {
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_trm_h1, tvb, 0,
                                    H0H1_LENGTH, ENC_LITTLE_ENDIAN);
                dissect_mtp3mg_trm(payload_tvb, pinfo, mtp3mg_tree, h1);
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            break;
        case H0_DLM:
            if (mtp3_standard != JAPAN_STANDARD)
            {
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_dlm_h1, tvb, 0,
                                    H0H1_LENGTH, ENC_LITTLE_ENDIAN);
                dissect_mtp3mg_dlm(payload_tvb, pinfo, mtp3mg_tree, h1);
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            break;
        case H0_UFC:
            if (mtp3_standard != JAPAN_STANDARD)
            {
                proto_tree_add_item(mtp3mg_tree, hf_mtp3mg_ufc_h1, tvb, 0,
                                    H0H1_LENGTH, ENC_LITTLE_ENDIAN);
                dissect_mtp3mg_ufc(payload_tvb, pinfo, mtp3mg_tree, h1);
            } else
                dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
            break;

        default:
            col_set_str(pinfo->cinfo, COL_INFO, "Unknown ");

            dissect_mtp3mg_unknown_message(tvb, pinfo, mtp3mg_tree);
        } /* switch */
    } /* else */

    return tvb_captured_length(tvb);
}

void
proto_register_mtp3mg(void)
{

    /* Setup list of header fields  See Section 1.6.1 for details*/
    static hf_register_info hf[] = {
        { &hf_mtp3mg_h0,
            { "H0 (Message Group)", "mtp3mg.h0",
              FT_UINT8, BASE_HEX, VALS(h0_message_type_values), H0_MASK,
              "Message group identifier", HFILL }},
        { &hf_mtp3mg_chm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(chm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_ecm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(ecm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_fcm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(fcm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_tfm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(tfm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_rsm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(rsm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_mim_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(mim_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_trm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(trm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_dlm_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(dlm_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_ufc_h1,
            { "H1 (Message)", "mtp3mg.h1",
              FT_UINT8, BASE_HEX, VALS(ufc_h1_message_type_values), H1_MASK,
              "Message type", HFILL }},
        { &hf_mtp3mg_coo_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT16, BASE_DEC, NULL, ANSI_COO_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_coo_ansi_fsn,
            { "Forward Sequence Number", "mtp3mg.fsn",
              FT_UINT16, BASE_DEC, NULL, ANSI_COO_FSN_MASK,
              "Forward Sequence Number of last accepted message", HFILL }},
        { &hf_mtp3mg_coo_itu_fsn,
            { "Forward Sequence Number", "mtp3mg.fsn",
              FT_UINT8, BASE_DEC, NULL, ITU_COO_FSN_MASK,
              "Forward Sequence Number of last accepted message", HFILL }},
        { &hf_mtp3mg_xco_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT32, BASE_DEC, NULL, ANSI_XCO_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_xco_ansi_fsn,
            { "Forward Sequence Number", "mtp3mg.fsn",
              FT_UINT32, BASE_DEC, NULL, ANSI_XCO_FSN_MASK,
              "Forward Sequence Number of last accepted message", HFILL }},
        { &hf_mtp3mg_xco_itu_fsn,
            { "Forward Sequence Number", "mtp3mg.fsn",
              FT_UINT24, BASE_DEC, NULL, 0x0,
              "Forward Sequence Number of last accepted message", HFILL }},
        { &hf_mtp3mg_cbd_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT16, BASE_DEC, NULL, ANSI_CBD_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_cbd_ansi_cbc,
            { "Change Back Code", "mtp3mg.cbc",
              FT_UINT16, BASE_DEC, NULL, ANSI_CBD_CBC_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_cbd_itu_cbc,
            { "Change Back Code", "mtp3mg.cbc",
              FT_UINT8, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_cbd_japan_cbc,
            { "Change Back Code", "mtp3mg.cbc",
              FT_UINT8, BASE_DEC, NULL, JAPAN_CBD_CBC_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_eco_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT8, BASE_DEC, NULL, ANSI_ECO_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_ansi_apc,
            { "Affected Point Code", "mtp3mg.ansi_apc",
              FT_STRING, BASE_NONE, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_apc_member,
            { "Affected Point Code member", "mtp3mg.apc.member",
              FT_UINT24, BASE_DEC, NULL, ANSI_MEMBER_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_apc_cluster,
            { "Affected Point Code cluster", "mtp3mg.apc.cluster",
              FT_UINT24, BASE_DEC, NULL, ANSI_CLUSTER_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_apc_network,
            { "Affected Point Code network", "mtp3mg.apc.network",
              FT_UINT24, BASE_DEC, NULL, ANSI_NETWORK_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_tfc_ansi_status,
            { "Status", "mtp3mg.status",
              FT_UINT8, BASE_DEC, NULL, ANSI_TFC_STATUS_MASK,
              "Congestion status", HFILL }},
        { &hf_mtp3mg_itu_apc,
            { "Affected Point Code (ITU)", "mtp3mg.apc",
              FT_UINT16, BASE_DEC, NULL, ITU_PC_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_tfc_itu_status,
            { "Status", "mtp3mg.status",
              FT_UINT16, BASE_DEC, NULL, ITU_TFC_STATUS_MASK,
              "Congestion status", HFILL }},
        { &hf_mtp3mg_chinese_apc,
            { "Affected Point Code", "mtp3mg.chinese_apc",
              FT_STRING, BASE_NONE, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_tfc_japan_spare,
            { "TFC spare (Japan)", "mtp3mg.japan_spare",
              FT_UINT8, BASE_HEX, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_japan_apc,
            { "Affected Point Code", "mtp3mg.japan_apc",
              FT_UINT16, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_tfc_japan_status,
            { "Status", "mtp3mg.japan_status",
              FT_UINT8, BASE_DEC, NULL, JAPAN_TFC_STATUS_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_tfc_japan_status_spare,
            { "Spare (Japan)", "mtp3mg.japan_spare",
              FT_UINT8, BASE_HEX, NULL, JAPAN_TFC_STATUS_SPARE_MASK,
              NULL, HFILL }},
        { &hf_mtp3mg_tfm_japan_count,
            { "Count of Affected Point Codes (Japan)", "mtp3mg.japan_count",
              FT_UINT8, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_tfm_japan_spare,
            { "Spare (Japan)", "mtp3mg.japan_spare",
              FT_UINT16, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_rsm_japan_count,
            { "Count of Affected Point Codes (Japan)", "mtp3mg.japan_count",
              FT_UINT8, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_rsm_japan_spare,
            { "Spare (Japan)", "mtp3mg.japan_spare",
              FT_UINT16, BASE_DEC, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_mim_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT8, BASE_DEC, NULL, ANSI_MIM_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_dlc_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT24, BASE_DEC, NULL, ANSI_DLC_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_dlc_ansi_link,
            { "Link", "mtp3mg.link",
              FT_UINT24, BASE_DEC, NULL, ANSI_DLC_LINK_MASK,
              "CIC of BIC used to carry data", HFILL }},
        { &hf_mtp3mg_dlc_itu_link,
            { "Link", "mtp3mg.link",
              FT_UINT16, BASE_DEC, NULL, ITU_DLC_LINK_MASK,
              "CIC of BIC used to carry data", HFILL }},
        { &hf_mtp3mg_upu_user,
            { "User", "mtp3mg.user",
              FT_UINT8, BASE_HEX, VALS(service_indicator_code_vals), UPU_USER_MASK,
              "Unavailable user part", HFILL }},
        { &hf_mtp3mg_upu_cause,
            { "Cause", "mtp3mg.cause",
              FT_UINT8, BASE_HEX, VALS(upu_cause_values), UPU_CAUSE_MASK,
              "Cause of user unavailability", HFILL }},
        { &hf_mtp3test_h0,
            { "H0 (Message Group)", "mtp3mg.test.h0",
              FT_UINT8, BASE_HEX, VALS(test_h0_message_type_values), H0_MASK,
              "Message group identifier", HFILL }},
        { &hf_mtp3mg_test_h1,
            { "H1 (Message)", "mtp3mg.test.h1",
              FT_UINT8, BASE_HEX, VALS(test_h1_message_type_values), H1_MASK,
              "SLT message type", HFILL }},
        { &hf_mtp3mg_test_length,
            { "Test length", "mtp3mg.test.length",
              FT_UINT8, BASE_DEC, NULL, H1_MASK,
              "Signalling link test pattern length", HFILL }},
        { &hf_mtp3mg_japan_test,
            { "Japan test message", "mtp3mg.test",
              FT_UINT8, BASE_HEX, VALS(japan_test_message_type_values), 0x0,
              "Japan test message type", HFILL }},
        { &hf_mtp3mg_japan_test_spare,
            { "Japan test message spare", "mtp3mg.test.spare",
              FT_UINT8, BASE_HEX, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_japan_test_pattern,
            { "Japan test message pattern", "mtp3mg.test.pattern",
              FT_UINT16, BASE_HEX, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_japan_spare,
            { "Japan management spare", "mtp3mg.spare",
              FT_UINT8, BASE_HEX, NULL, 0x0,
              NULL, HFILL }},
        { &hf_mtp3mg_test_ansi_slc,
            { "Signalling Link Code", "mtp3mg.slc",
              FT_UINT8, BASE_DEC, NULL, ANSI_TEST_SLC_MASK,
              "SLC of affected link", HFILL }},
        { &hf_mtp3mg_test_pattern,
            { "Test pattern", "mtp3mg.test_pattern",
              FT_BYTES, BASE_NONE, NULL, 0x0,
              NULL, HFILL }},
  };

    /* Setup protocol subtree array */
    static int *ett[] = {
        &ett_mtp3mg,
        &ett_mtp3mg_fcm_apc,
        &ett_mtp3mg_tfm_apc,
        &ett_mtp3mg_rsm_apc,
        &ett_mtp3mg_upu_apc
    };

    static ei_register_info ei[] = {
        { &ei_mtp3mg_unknown_message, { "mtp3mg.unknown_message", PI_PROTOCOL, PI_WARN, "Unknown message", EXPFILL }},
    };

    expert_module_t* expert_mtp3mg;

    /* Register the protocol name and description */
    proto_mtp3mg = proto_register_protocol("Message Transfer Part Level 3 Management",
                                           "MTP3MG", "mtp3mg");
    mtp3mg_handle = register_dissector("mtp3mg", dissect_mtp3mg, proto_mtp3mg);

    /* Required calls to register the header fields and subtrees used */
    proto_register_field_array(proto_mtp3mg, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    expert_mtp3mg = expert_register_protocol(proto_mtp3mg);
    expert_register_field_array(expert_mtp3mg, ei, array_length(ei));

}

void
proto_reg_handoff_mtp3mg(void)
{
    dissector_add_uint("mtp3.service_indicator", MTP_SI_SNM, mtp3mg_handle);

    /*  SI 1 is unused in ANSI and SI 2 is unused in ITU, so it's okay for us
     *  to grab both (regardless of mtp3.standard setting) here.
     */
    dissector_add_uint("mtp3.service_indicator", MTP_SI_MTN, mtp3mg_handle);
    dissector_add_uint("mtp3.service_indicator", MTP_SI_MTNS, mtp3mg_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */