handbook

The

DCME Handbook

By Joseph Swanson

The DCME Handbook
© 1999 by Joseph Swanson.

The preface and foreword are © 1999 by Luís Sousa Cardoso and ECI Telecom respectively.
Registered trademarks and logos mentioned in the DCME Handbook are the property of their owners. The opinions expressed in the DCME Handbook are those of the authors and not necessarily those of PDMI Ltd.

Table of Contents

Preface               by Luís Sousa Cardoso, Chairman of the QSDG

Foreword           by ECI Telecom

Introduction     by Joseph O. Swanson

Part 1 Recommendations

1. Objective / Background

2. Scope of the Handbook

3. Recommended Settings

      3.1 ECI Telecom

      3.2 Alcatel

      3.3 Mitsubishi

4. Record Keeping

Part 2 A Guide For Coordination

1. General

2. Role of the Coordinator

3. Implementation Procedure

Part 3 Appendices

Appendix A1 DCME Configurations Settings Form

Appendix A2 DCME History Form

Appendix A3 DCME Summary Table

Appendix B1 ECI DCME Contact Information

Appendix B2 MCI Operations Contact Information

Appendix C Special Testing Setup Procedure

Appendix D DCME Guideline

Appendix E Technical Note

Appendix E1 ECI Telecom DTX-240E/F

      A. Configuration Change

      B. Fax Demodulation, V.17

      C. Message Interleaving

      D. Signaling

About the author

Preface

By Luís Sousa Cardoso

International telecommunications traffic is growing every year, making it necessary for carriers to continuously expand capacity. Among the growth factors it is necessary to take into account the use of facsimile terminals. The DCME equipment is the fastest and the most cost-effective way to ease congestion. While DCME has been implemented on international routes it is now being applied in a number of domestic networks. But the use of this equipment should be carefully applied, adhering to strict criteria in order to avoid line quality degradation.

Joe Swanson - one of the Quality of Service Development Group’s most active members - and his team have prepared The DCME Handbook as a useful guide for all technical people involved in the use of this type of equipment. The result is magnificent.

The DCME Handbook should be kept nearby as a road map on how to set up DCME. It is a very useful tool to be studied, understood, and followed.

As chairman of the QSDG, it is an honor for me to have in the group people like Joe and his team with the fantastic skill to produce such a work. I also believe that ECI should be proud to sponsor the book and of the support they have given to the QSDG. I hope that all readers of this book will consider The DCME Handbook an indispensable tool.

Luís Sousa Cardoso
QSDG CHAIRMAN

Foreword

ECI Telecom, an acknowledged innovator in the telecommunications industry, is continuously upgrad-ing its Digital Circuit Multiplication Equipment (DCME) products in order to keep pace with new services offered by international and global carriers and rapid advances in technology. Today, more than 70 percent of the international toll quality voice traffic around the world is provided through ECI Telecom’s DTX-240 and DTX-360 systems.

The DCME Handbook has been prepared by Joe Swanson and his team at MCI Worldcom to help the DCME user to optimize network performance and improve the quality of traffic carried via DCME. We hope that DCME users will find it useful.

ECI Telecom strongly believes in co-operaton on international standards and is proud to sponsor the publication of The DCME Handbook. As a member of the ITU, ECI is active in Study Group 15 of the ITU-T, and through its US associate company, ECTel, it attends the Quality of Service Development Group (QSDG) meeting every year. ECI took the lead in the DCME arena in 1986, after winning a tender to provide DCME for TAT-8, the first transatlantic fiber optic cable, which came into service in 1988.

Support for standards development comes naturally for a company such as ECI. For example, ECI features toll quality as an integral feature of its DCME products. Toll quality refers to how a customer hears a telephone call. It is a subjective concept and can’t be easily tested. But no major carrier would ever accept equipment that is not toll quality to carry telephone traffic over public networks. Defining esoteric concepts such as toll quality is one reason why ECI is firmly supportive of Quality of Service issues through the ITU.

ECI Telecom’s most recent innovation to the DTX-240 family is the new host processor, the Main CPU Enhanced, or MCPU/E for short. This new card replaces the present MCPU/N card. The new MCPU/E will, of course, be compatible with the existing systems, although the biggest gains will be realized when systems on both ends of the network line will be fitted with MCPU/Es.

Of special interest to network service providers is the new extended far-end configuration report, which is supported by the new MCPU/E card and which provides a comprehensive far-end configura-tion report. This report allows the operator to optimize terminal performance by automatically comparing near-end terminal configuration with that of the far-end terminal. In addition, the extended far-end configuration report triggers an automatic deferred alarm in the case of traffic affecting configuration mismatch.

Facsimile takes a significant part in today’s PSTN traffic. The fax demodulation technique implemented in the DTX Product family, with its intrinsic repeater effect, is not only essential for the multiplication of digital link capacity but also for the Quality of Service of facsimile calls. The unique Waveform Analysis demodulation technique implemented in the DTX-240F, DTX-240T and DTX-360 systems, enables these products to support both standard and non-standard Group 3 Facsimile calls including V.17 transmissions at rates up to 14.4 Kbit/s.

The DTX-360 is the first DCME to provide up to 10:1 toll quality compression. Utilizing Digital Speech Interpolation (DSI), Low Delay, Code Excited Linear Prediction (LDCELP), Adaptive Differen-tial Pulse Code Modulation (ADPCM), Variable Bit Rate encoding (VBR) and Fax demodulation/ remodulation techniques, the DTX-360 delivers maximum effective compression, together with a very high level of signal quality and system reliability.

Built on a solid foundation of customer commitment and technological excellence, ECI Telecom provides leading edge digital telecommunications and data transmission systems which increase network capacity, flexibility and profitability.

By including ECI Telecom equipment in their networks, equipment that has been optimally configured, network device providers can offer their customers significantly improved telecommunications performance and thereby increase the Quality of Service at a substantially lower cost.

Introduction

My objective in producing the DCME Handbook is to create a meaningful and widely accepted document for the implementation and management of DCME–Digital Circuit Multiplication Equipment. I hope it will be used by carriers worldwide to ensure the highest possible telephone service quality using DCME technology. It is my fervent wish that this work will find its way into every operations and engineering room in which DCME equipment is employed.

The mission of this work at its inception was to identify a process and configuration that would work well in all the various network configurations. The finding and recommendations put for th in the DCME Handbook are based on empirical test data which was collected on live network traffic –not in a lab–through many months of effort. This test data and details of our effort are available form the ITU-T in document QSDG 14/97-23.

This work is not intended to be taken as the be-all and end-all of DCME management but rather as a process that has proven to work in all networks where it has been implemented. Indeed, there may be a better and more perfect means for managing DCME but the results that we at MCI Worldcom have achieved using these guidelines will probably remove all incentive to search further. That is, at least with respect to the DCME technologies, covered in this text.

For example, my colleague Bertrand Thomas of France Telecom has correctly pointed out that one of my recommended settings seems to be in conflict with ITU-T Recommendation G.113, regarding quantization distortion units (QDU) and deserves further study. However, the performance realized on our mutual route is such that there is little incentive to study this issue further at least at the operations level.

Finally, I wish to thank my many colleagues around the world for their assistance and cooperation. Without their support and willingness to share their knowledge and experience this work would not have been possible.

My thanks to Luís Sousa Cardoso, chairman of QSDG and the department head for the quality of service and network security group at Marconi Por tugal; Robert Pearson manager, international traffic operations at Optus; Philip Mann, group leader international network efficiency at Optus; Ernie Cable, capacity planning manager for BT; Terry Smith, correspondent business executive for North America for BT’s international carrier sales department; Derek Burnside, manager, customer support for ECtel; Simon Cox, senior advisor, global design with BT Systems Engineering; Haim Guata, director product marketing, DCME for ECI Telecom; George Turoczy, director international, MCI WorldCom; Chandra Pandy, manager engineering, MCI WorldCom; Paul Bouillon, manager MCI WorldCom; Denis Scarfagnia, manager of international customer services for Telecom Italia; Kazunori Matsuo director, network service center at KDD in Tokyo; Bonnie Gray, general manager European operations for Primus Telecommunications; and Jerry Courtemanche, senior manager for European switches for Primus Telecommunications. I would like to offer a special thanks to ECI Telecom for all their support in providing data and funding the publication of the DCME Handbook. Lastly I want to recognize my staff assistant Mr. Nobuhiko Koyama. His assistance and dedication to the task of collating and managing information were largely responsible for my being able to produce this work.

Joseph Swanson
MCI Worldcom
February, 1999

Part One

Recommendations

1. Objective / Background

This Handbook provides recommendations and guidelines for configuring and optioning DCME for optimal performance. Optimization of DCME presents a large opportunity to improve quality, which in turn leads to increased revenues. The objective of this Handbook is to provide technicians and managers with practical guidance for the purpose of optimizing DCME performance.

As presented in the QSDG meeting in Manama, Bahrain in April 1997, some international carriers in the past had experienced problems in the performance of facsimile traffic. Subsequent investigations found that many of the problems were related to the mismatches in the configurations of the near-and far-end DCME units. The main points of that presentation are restated below:

1. The current technology and available hardware are capable of supporting voice and non-voice services with a very high level of quality if properly configured.

2. Optimization of DCME presents a very large opportunity to improve quality and revenue. 3. The single largest contributing factor to the problems experienced is the absence of a globally accepted and followed guideline for the installation, configuration and management of DCME. 4. At a minimum the following can significantly improve DCME performance:
Obtain the latest revision of firmware.
Matching Options Setting. Generally speaking it is more important that each end be optioned the same rather than having one optioned for optimum performance and the other not.
Communicate with your correspondent. Unilateral and unco-ordinated action is responsible for the offsystem mismatches.

As a result of discussions on both bilateral and multilateral bases and, after lengthy consultation with the vendors, an agreement for configuration and optioning the units was reached. The recommended settings in this Handbook are based on this agreement.

2. Scope of the Handbook

The effort to develop this Handbook has resulted in three parts. Part 1 contains the recommended settings for three of the DCME types most commonly used by carriers today. The tables in Section 3, Recommended Settings, provide technicians with specific optimal settings for different types of DCMEs. These are the option settings that are recommended at the time of system commissioning. Also, these are the references for reviewing existing systems. Part 2 presents a guide for co-ordinating the optimization of existing DCMEs. It illustrates a step-by-step procedure for the DCME optimization from the co-ordinator’s viewpoint.

Part 3 is appendices, which include forms for recording DCME settings and changes, DCME Guide-lines and technical notes, where supplementary information useful in understanding DCME options is attached.

Finally, it is not the intention of this Handbook to illustrate step-by-step installation, operation and maintenance procedures for any specific DCME terminal. For details of these types of procedures, refer to respective manufacturer’s manuals.

3. Recommended Settings

3.1 ECI Telecom

Table 3.1 Recommended Settings for ECI DTX-240E/F

On standard 2 Mbit/s bearer

No.

Item

Recommended Settings

K

DTX-240E

DTX-240F

1

OPS S/W Version

6.7 or later

6.7 or later

1

2

MCPU S/W Version

MUF0007X.35 or later 4

MUF0007X.35 or later 4

1

3

FDEM Cards Type

N/A

FDEM/N

3

4

VBD Configuration

Large

Large

3

5

Dynamic Limit

55

55

3

6

Silence Elimination

Enable

Enable

2

7

DLC Upon Bit-Rate

3.7 bits

3.7 bits

1

8

DLC Hangset ON

5 sec

5 sec

1

9

DLC Hangset OFF

10 sec

10 sec

1

10

DLC Upon VBD Calls

45 VBD calls

45 VBD calls

1

11

DLC Upon Freezout ON

0.1%

0.05%

1

12

DLC Upon Freezout OFF

0.05%

0.1%

1

13

Time-Slots in Config

Match*

Match

2

14

Nibbles in Config

Match

Match

2

15

VBR

Enable

Enable

1

16

Time Slot 0

Transparent

Transparent

2

17

DOM

Disable

Disable

1

18

Noise (adaptive)

a) Measure: Enable b) Inject : Disable

c) Measure: Enable d) Inject : Disable

3

19

CCPU

e) Disable if not equipped f) Enable if equipped

g) Disable if not equipped h) Enable if equipped

1

20

Alarm Extension

"Per bit stream" if CCPU (Q.50) is disabled at least at one end "Per time slot" if CCPU(Q.50) is enabled at both ends

"Per bit stream" if CCPU (Q.50) is disabled at least at one end "Per time slot" if CCPU(Q.50) is enabled at both ends

2

21

CAS Signalling (SCPU)

Disable

Disable

2

22

Speech Detector

2^nd threshold

2^nd threshold

1

23

Fax Compression

N/A

Enable

2

FEC

N/A

Enable for satellite routes, Disable for cable routes

2

V.17

N/A

Enable

2

24

Message Interleaving

Enable

Enable

2

25

Multi-Frame On Bearer

Disable

Disable

2

26

Bit Stream In Config

27

Bearer Monitor

Disable

Disable

28

Bearer Starting TS

01

01

2

29

Bearer Number Of TS

31

31

2

30

Clocks Config

1

Operating Parameters

The recommended option settings for DTX-240E and DTX-240F for use on standard 2 Mbit/s bearer are shown in Table 3.1. For a system where terminals at both ends are of the same type, option settings on each terminal should be set according to the recommended settings for that type. If one end is of DTX-240E type (no fax demodulation capability) and the other end is of DTX-240F type, both terminals should be configured following the settings under DTX-240E. For items with N/A on the DTX-240E column, the item should be disabled on the DTX-240F terminal.

2
Dependency scale. K=1: each end may be set independently; K=2: both ends must have the same setting; K=3: each end may be set independently but the result is affected by both options selected.

3
Both ends must be equipped with /N type cards in order to enable V.17 option. If at least one end is equipped with old FDEM cards, V.17 option must be disabled at both ends.

4
The terminal must be equipped with MCPU/N, FMOD/N and FDEM/N cards. Otherwise, V.17 option must be disabled at both ends.

5, 6
Terminal must be equipped with MSGR/N and MSGT/N cards in order to enable message interleaving.

Variations to standard for IDR Carriers 1Mb/s and 512Kb/s

1Mb/s
DYNAMIC LIMIT                :    26, T-mode or Non-Transparent B0
VBD CONFIGURATION           :    SMALL, Bearer number of B = 16
NIBBLES IN CONFIGURATION    :    31 1 Check for B16 out of configurataion on modem.

512kbs
DYNAMIC LIMIT                :    10
VBD CONFIGURATION           :    SMALL
NIBBLES IN CONFIGURATION    :    15 2 Bearer Number of B = 8 (May be different as long as switches agree. For example, T-1 to E-1 trunk).
1 Assuming no data link or IPPL circuit on the bearer for each DL or 64K IPL circuits a value of two should be subtracted if DL is DACSed on bearer side.
2 assuming no data link or IPL circuit on the bearer for each DL or 64K IPL circuits, a value of 2 should be subtracted.

Table 3.2 Recommended Settings for ECI DTX-360

No.

Item

Recommended Settings

K²

LD-CELP

ADPCM

1

OPS S/W Version

Pulsar 5.2.1¹

3

2

DCME mode

Enhanced (LD-CELP)

IESS-501 (ADPCM)

2

3

Operational mode

Point-to-Point

Point-to-Point

2

4

Bearer Pool

Match

Match

2

5

Bearer Channel Assign

Match

Match

2

6

Trunk Channel Assign

Match

Match

2

7

Clocks

1

8

Signaling: CAS

Match

Match

2

9

Signaling: CCS

Match

Match

2

10

Signaling: Q.50

1

11

Fax Demod/Remod

On

On

2

12

FEC³

Enable for satellite routes

Disable for cable routes

2

13

Fax Backward via VBD

Off

Off

2

14

Alarm extension

Per bitstream if Q.50 is disabled at least at one end.

Per time slot if Q.50 is enabled at both ends

2

15

Speech detector

Adaptive

Adaptive

1

16

Data activity threshold

-35 dBm

-35 dBm

1

17

Noise injection

Matched

Matched

1

18

DLC

Average bits per sample Data bearer occupancy

1^st stage averaging period (msec)

Voice/VBD deactivation (sec)

1.87 (High)/1.92 (low)

90 (High)/70 (Low)

128

10

3.7 (High)/3.9 (Low)

90 (High)/70 (Low)

128

10

1

1

1

1

19

VBD hangover

1^st hangover (sec)

2^nd hangover (msec)

10

100

10

100

1

1

1
Prior to SW upgrade, consult with ECI Telecom and verify whether the SW upgrade requires any HW modifications.
2
Dependency scale: K-1: each end may be set independently; K-2: both ends must have the same setting; K-3: each end may be set independently but the result is affected by both options selected.
3
For a fiberoptic link - Off For a satellite link - On

Notes
1. Before obtaining the configuration, be sure to perform “GET CONFIGURATION” from the Operator Station OPS to ensure that you will receive updated information.

2. After configuration changes are made, it is recommended that the terminal be reset by pressing the reset button located on the RT shelf. A caution is advised since this operation will interrupt traffic for a brief period of time. Also, “GET CONFIGURATION” should be executed to make sure that the new configuration is saved in the hard disk. For more details, refer to “CONFIGURATION CHANGE” in Appendix E Technical Note.

3. For explanation of some of the key options, see Appendix E Technical Note.

Gain

In practice, standard links (29/30 timeslot bearers) are designed with a nominal gain of 4.0.

The factors determining the gain setting for links with smaller capacity (limited timeslot applications) are: bearer pool size and fax compression enabled/disabled. The prime parameter remains the bits/ sample and this parameter remains set at 3.7.

The table below shows maximum settings for each fax compression status.

Alcatel 3G DCMS CONFIGURATION (Proposal)

	Terminal Config
Oper Stat	Yes
Trunks	2048_kb/s
Bearer	2048_kb/s
Bundle 1	Yes
Bundle 2	No
Bundle 3	No
Bundle 4	No
Sync Mode	Trunk
Anal Data	9.6 OPT_B
PCM 0-7	BUNDL-1 or NON_EXI as required
	Bundle 1 Config
Mapping	No
DLC	Yes
STM	No
OVLD Chan	3&2 Bits
	Bundle 1 DLC
Activation	3.7-bit/Sample
Threshold	5-Sec
Deactivation	3.9-bit/Sample
Threshold	10-Sec
	Config PCM 0-7 (as required)
Exits	Yes
Echo	Ext-E-Can (PTT may option as required)
Encod Mod	Variable
Signaling	(option as required)
ABCD bits	(option as required)
	Config Bearer
TS 0-31	Bdle 1
	Signalling Channel Assignement
Bundle 1	Signaling Unit=1 Signaling Channel=16

3.3 Mitsubishi

MITSUBISHI DX-3000

------------------

This represents 4:1 system gain without a clear channel. Both trunk and bearer interfaces are at E1 (2.048 Mbps) level.

Mode Map

No.	Item	Recommended Setting
1	Trunk interface mode	( 0:1.5M 1:2M ): 1
2	Bearer interface mode	( 0:1.5M 1:2M ): 1
3	Multiclique	( 0:Unuse 1:Use ): 0
4	BC boundary	( 2 - 30 ) :
		For Clique-1 and Clique-2
5	Number of AC	( 1 or 2 ) : See Note
6	Number of IC	( 1 - 216 ) : 120
7	DSI operation	( 0:Unuse 1:Use ): 1
8	DSI mode	( 0:32K 1:64K ): 0
9	Number of BCs for DSI	( 1 - 61 ) : See Note
10	Overload channel	( 0:Unuse 1:Use ): 1
11	32K DNI	( 0:Unuse 1:Use ): 0
12	Number of BCs for 32K DNI	( 1 - 61 ) :
13	64K DNI	( 0:Unuse 1:Use ): 0
14	Number of BCs for 64K DNI	( 1 - 30 ) :

Note

If "Number of AC" is 1, "Number of BCs for DSI" should be set to 61.

If "Number of AC" is 2, "Number of BCs for DSI" should be set to 60.

DLC threshold

No.	Item	Recommended Setting
15	Time base [sec.]	( .5 / 1 / 2 / 4 / 10 / 30 ) : 10
16	DLC detection	(0:Encoding sample 1:Freezeout ) : 0
17	Remote terminal's DLC	( 0:Unuse 1:Use ) : 1
18	DLC threshold	( occurrence ) : 3.7 Encoding sample ( recovery ) : 3.9 Encoding sample

MITSUBISHI FC-3000

------------------

When used in conjunction with a DX-3000, Fax compression is provided. All

the DX-3000 setting are to be used unless specified below:

Forward Error Correction: ON

4. Record Keeping

One of the largest contributing factors for poor performance is inadequate record keeping. Having updated records of DCME settings at hand saves time in getting configuration from near-end and far-end terminals. Use of DCME Configuration Settings Form in Appendix A1 to maintain a hardcopy of updated near-end and far-end settings is helpful. It is recommended that this form be kept near each terminal where technicians can see it easily. The form should be updated whenever there is a change in option settings so that it will always reflect current settings.

Where the DTX-240E/F/T terminals are supported by the MCPU/E it is possible for the near end user to observe the far end configuration on their local station. Note: the majority of units deployed do not have this capability but can be upgraded for a cost.

The DCME History Form in Appendix A2 is used to keep track of changes made to each terminal in the past. Sometimes it helps to review the history of the terminal before making any changes. For example, if the fax demodulation option is disabled in a system with DTX-240F type terminals, there should be a reason. The reason should be described in the History Form. The form should be kept together with the above Settings Form.

Part Two

A Guide For Coordination

1. General

In Part 1, recommended settings for three brands of the commonly used DCMEs are outlined. Part 1 describes what option settings of each DCME should be, but not how to implement the optimization.

To successfully realize the optimization of DCME requires an organizational initiative, commitment of all par ties concerned and orderly co-ordination amongst different organizations. A co-ordinator who initiates and promotes the optimization activity plays a key role for the smooth implementation. This document presents step-by-step guidance for the optimization of existing DCME. The co-ordinator for the purpose of this document resides in MCI Worldcom and interacts with some specific organi-zational units within MCI Worldcom as well as with the correspondent carrier. Also, the types of DCME focused here are ECI Telecom’s DTX-240E and DTX-240F. However, it is hoped that this document will serve as a practical reference for implementing the optimization of any type of DCME for any carrier.

2. Role of the Co-ordinator

The principal organizations involved in the implementation of DCME optimization are the two network operators that own the DCME terminals at both ends. There are sub-organizations within each entity, such as site maintenance and operations, planning, and quality assurance. Figure 1 illus-trates an example of parties involved with the implementation of DCME optimization and their relations among each other. In Figure 1, the network operator in which the co-ordinator resides is designated as MCI Worldcom for convenience. MCI Worldcom may be substituted by the reader’s organization when applying the process to his/her own implementation.

Organizations Involved with Implementation

The co-ordinator plays a crucial role in the implementation. As illustrated in Figure 1, the co-ordinator is positioned at the center of the parties involved and has direct contact with all the parties. The implementation is initiated and makes progress by action of the co-ordinator, who co-ordinates among the parties through all steps of the implementation. Of the four major stages of implementa-tion – initiation, preparation, execution and confirmation – the co-ordinator plays a key role in facilitating all stages of the process.

3. Implementation Procedure

The entire implementation process can be broken into four major stages: initiation, preparation, execution and confirmation. In the initiation stage, DCMEs subject to optimization are determined, and the carrier contact person, or the counterpart, is identified. During the preparation stage, all the information necessary for optimization is gathered and arrangement for execution is made. In the execution stage, changes in option settings are made. Finally, absence of abnormality and improved performance are verified during the confirmation stage.

The flowchart in Figure 2 shows the specific steps for the implementation from the co-ordinator’s viewpoint. Since these steps are developed based on MCI Worldcom’s experience, some of the descriptions are specific to MCI Worldcom’s organizations. It is hoped that these steps will serve as a reference and that the readers will use their discretion for their own application. Detailed explana-tion of each step follows next.

Implementation Steps for DCME Optimization from co-ordinator’s viewpoint

1. Identify the carrier to work with
Decide on a carrier to perform optimization with.

2. Identify all the mutual DCMEs
Find out how many mutual DCMEs exist and which near-end and far-end sites are involved. Refer to Network Design Order (NDO) to get this info. Record DCME designation, bearer designation, DCME type, H/W version, type of facility (cable or satellite) and near-end and far-end site names for each system. See Appendix A3 for an example of the table.

3. Identify carrier’s counterpart
With some carriers and depending on the timing, this process might take a few weeks. You can proceed to step 5 without waiting to complete this step. Once your counterpart has been identified, exchange each other’s phone and fax numbers and email addresses.

4. Confirm mutual target with counterpart
Explain to your counterpart the objective of your contact with some background information. Get consensus from your counterpart to work towards the mutual target. Below is an example of the message for initial contact:

As per our telephone conversation, I am sending this note to explain the purpose of my contact. The purpose of my contact is to get started with reconfiguring the option setting of the existing DCMS that we have between Telecom Italia and MCI Worldcom. The background for this activity is described below.

As presented in the QSDG meeting in Manama, Bahrain in April, 1997, MCI Worldcom in the past had experienced problems in the performance of facsimile traffic. The investigation found that many of the problems were related to the mismatches in the configurations of the near- and far-end DCME units. MCI Worldcom indicated that optimization of the DCME presents a very large opportunity to improve service quality. As a result of discussions on a multilateral basis among MCI Worldcom, British Telecom, Optus Communications and Telecom Italia, an agreement for configuration and optioning the units has been reached. Details are described in document QSDG 13/97/23 “IMPROV-ING SERVICE QUALITY THROUGH THE OPTIMIZATION OF CIRCUIT MULTIPLICATION EQUIPMENT,” presented at the QSDG meeting in April, 1997.

Having given the background, MCI Worldcom now wishes to initiate implementation of DCMS optimization with Telecom Italia. I will be the MCI Worldcom’s contact to co-ordinate this activity. I will first need to identify my counterpart, who will be co-ordinating the optimization activities among your organization. Further details can be discussed after my counterpart has been identified. If you have any questions, please feel free to contact me.

5. Get current settings from near-end terminals
For ECI’s DTX-240 D/E/F/T type terminals, obtain the current settings for each near-end DCME and fill in the corresponding items in the “DCME Configuration Settings Form“, as shown in Appendix A1. If you can get the setting information electronically using a remote terminal, do so. If not, the best way to obtain the settings is to ask the person in charge of DCME to send you the “Far-end Configu-ration Report” and the “Complete Configuration Report” for each terminal. The “Far-end Configura-tion Report” is one page and cannot be sent electronically, so use fax. The “Complete Configuration Report” is about 10 pages long and is easier to get it as an attachment to email. See Appendix B2 for MCI Worldcom operations contact information.

6. Recommended settings
In DCME Configuration Settings Form (Appendix A1), be sure to enter appropriate settings from Section 3. Recommended Settings in the column labeled “Recommended Setting” depending on DCME type. Refer to Table 3.1 for recommended settings for ECI DTX-240. The only difference between DTX-240E and DTX-240F is that fax compression is not available for DTX-240E type. Also, pay particular attention to FEC in item 24. Recommended FEC setting is ‘enable’ for satellite route and ‘disable’ for cable route. Be sure to write the correct FEC setting in the Guideline depending on the facility type.

7. Get current settings from far-end terminals
Obtain the far-end settings from your counterpart by asking them to fill out the “Carrier A Terminal” column of the DCME Configuration Settings Form. Ask your counterpart to return the completed form as soon as the setting info has been filled out. The Form can be sent electronically by email or by fax. With some carriers, you may have to contact different persons in charge of DCME for different sites, rather than the single contact point.

8. Critical discrepancy?
After obtaining settings on near-end and far-end terminals, compare each item with corresponding recommended setting. If an item has different settings between near- and far-end and the item is marked “C” under the “Note” column, it means that there is a critical discrepancy which is likely to cause transmission failure. If such an item is found, the setting should be matched immediately and should be subsequently reviewed.

9. Identify items to change for each DCME
Mark all items that differ from the settings in the Guideline. Make a summary table of items that need to be changed for each system. An example is shown below. The following option items need special attention. Confirm with sites involved if the terminals are equipped with required cards.

Item To Enable Requirement V.17 FDEM/N cards Message interleaving MSGR/N, MSGT/N cards Finally, pay attention to the MCPU firmware version. If the carrier’s terminals are equipped with an old version firmware, have them upgraded promptly. ECI contact is listed in Appendix B1.

10. Arrange measurements (optional)
It is a good idea to measure the performance of the DCME throughout the optimization process so that you can note the performance differences, if any, between before and after optimization. MCI Worldcom has a means to make test calls via a specific DCME and to take measurements. The detailed process is described in Appendix C.

11. Propose a time schedule
After all items to change have been identified, you should discuss with your counterpart the time schedule to make the changes. As a rule of thumb, you should allow two weeks from the time you send out a specific proposal to your counterpart to the date of carrying out changes. Actual time required to carry out changes varies depending on the number of items to change, but when plan-ning a time schedule, you should allow half an hour to an hour per system. Also, if the system needs to be down for some time to do the changes, busy hours should be avoided as much as possible. Each site has different staffing hours. Before submitting a formal proposal, call the manager or a person in charge in each site and ask if the time you are planning is convenient for them.

12. Send request to appropriate authority
After receiving informal consent to the proposed time schedule from each site, send a request message to the group in charge of authorizing making changes to DCME settings. The request message should include:

1) Proposed time schedule with DCME designation, gateway and far-end site, and bearer designation
2) Items to change.
An example of the message is shown below. We have a proposed DCMS reconfiguration schedule with Bagnolet, France Telecom as shown below. Would you please issue orders and confirm the schedule with our sites concerned. 1. DCME XBW, bearer BAGNOLET-POT 30N240 - Tuesday 25th November @ 10.00GMT
2. DCME XCJ, bearer BAGNOLET-DMH 30N210 - Tuesday 25th November @ 15.00GMT

The DCME type at carrier side is 240F. Below is a summary of the items that need to be changed. All of their terminals are equipped with /N type message cards.

13. Schedule confirmed?
After the formal change order has been sent to the sites, get confirmation from each site by email. If you do not receive an email response, initiate a phone call to obtain verbal confirmation.

14. Get name/phone of person in charge for each site
Ask each site manager who will be in charge to execute the change. Get the name and contact phone number of the person in charge so that the carrier can make contact at the scheduled time. Also, get the carrier’s contact information from your counterpart so that you can relay it to the person in charge in your organization.

15. Mutually decide who is going to initiate the call
Discuss with your counterpart or the carrier’s site person in charge and decide who is going to make the initial call. Convey this arrangement to persons in charge at both ends.

16. Send near-end contact info to counterpart
Send near-end contact person’s information to your counterpart.

17. Send far-end contact info and settings info to near-end person in charge
Send carrier contact person’s info, together with the time schedule, the summary table generated in step 9 and the current settings info obtained in steps 5 and 7, to the person in charge at the near-end site.

18. Execute
Configuration change is executed according to schedule.

19. Get confirmation from each site about changes
After the change has been executed, obtain a confirmation message from each person in charge. If you don’t receive the message within 24 hours after execution, call them for confirmation.

20. Assess measurement data (optional)
If you set up measurement of the test calls in step 10, continue the measurement at least for one week after optimization. Plot the data. Assess the measured data in relation to the optimization activity.

21. Any problem?
If you observe any problem in the measured data or by other means, contact the respective site, identify the cause and rectify the problem. Share the issue with your counterpart.

22. Report assessment result to counterpart (optional)
Share the assessment result in step 20 with your counterpart.

23. Report optimization completion to all parties concerned
Report completion of the optimization activity to all parties concerned, including your counterpart as well as the appropriate authority.

24. Organize documentation for referral
Organize all documentation, including contact information, route information, update settings informa-tion and measured data, for later referral.

Part Three

Appendices

Appendix A1 DCME Configurations Settings Form

Appendix A1 DCME Configuration Settings Form

Country A:	Carrier A:	GW:	DCME:
Country B:	Carrier B:	GW:	DCME:
Facility:	Bearer:	Gain:	Date Filled Out:	By: John Doe

No.	Item	Note*	Carrier A Terminal	Carrier B Terminal	Recommended Setting
1	DCME Type				DTX-240F
2	OPS S/W Version
3	MCPU S/W Version				MUF0007X.34 or later
4	FDEM Cards In		FDEM: FDEM/N:	FDEM: FDEM/N:	FDEM: FDEM/N:
5	VBD Configuration		Large / Small	Large / Small	Large
6	Dynamic Limit				55
7	Silence Elimination	C	Enable / Disable	Enable / Disable	Enable
8	DLC Upon Bit-Rate				3.7
9	DLC Hangset ON				5 sec
10	DLC Hangset OFF				10 sec
11	DLC Upon VBD Calls				45 VBD calls
12	DLC Upon Freezout ON
13	DLC Upon Freezout OFF
14	Time-Slots in Config
15	Nibbles in Config
16	VBR		Enable / Disable	Enable / Disable	Enable
17	Time Slot 0	C			Transparent
18	DOM		Enable / Disable	Enable / Disable	Disable
19	Noise (adaptive)		Measure: Enable / Disable Inject: Enable / Disable	Measure: Enable / Disable Inject: Enable / Disable	Measure: Enable Inject: Disable
20	CCPU		Enable / Disable	Enable / Disable	Disable if not equipped
21	Alarm Extension	C	Per Bit Stream / Per Time Slot	Per Bit Stream / Per Time Slot	Per Bit Stream
22	SIG (SCPU)	C	Enable / Disable	Enable / Disable	Disable
23	Speech Detector				Second threshold
24	Fax Compression	C C	Enable / Disable with/w.o. FEC, with/w.o. V.17	Enable / Disable with/w.o. FEC, with/w.o. V.17	Enable with/w.o. FEC, with V.17
25	Message Interleaving	C	Enable / Disable MSGR(T) / MSGR(T)/N	Enable / Disable MSGR(T) / MSGR(T)/N	Enable MSGR/N, MSGT/N
26	Multi-Frame On Bearer	C	Enable / Disable	Enable / Disable	Disable
27	Bit Stream In Config
28	Bearer Monitor	C	Enable / Disable	Enable / Disable
29	Bearer Starting TS
30	Bearer Number Of TS
31	Clocks Config

Appendix A1

DCME Configurations Settings Form (example)

* C – Critical item. Both ends must have the same option selected, or transmission is likely to end up in faults.

Appendix A1 DCME Configuration Settings Form (Example)

Country A: Italy	Carrier A: Telecom Italia	GW: MILANO	DCME: MI EC46
Country B: USA	Carrier B: MCI	GW: POB	DCME: XAC, Terminal 3
Facility: CBL TAT-11	Bearer: POB-MIL30N001	Gain: 4:1	Date Filled Out: Oct. 10, 1997	By: John Doe

No.	Item	Note*	Carrier A Terminal	Carrier B Terminal	Recommended Setting
1	DCME Type			DTX-240F	DTX-240F
2	OPS S/W Version			6.2
3	MCPU S/W Version			MUF0007X.40	MUF0007X.34 or later
4	FDEM Cards In		FDEM: FDEM/N:	FDEM: FDEM/N: 01	FDEM: FDEM/N:
5	VBD Configuration		Large / Small	Large	Large
6	Dynamic Limit			55	55
7	Silence Elimination	C	Enable / Disable	Enable	Enable
8	DLC Upon Bit-Rate			3.7	3.7
9	DLC Hangset ON			05	5 sec
10	DLC Hangset OFF			20	10 sec
11	DLC Upon VBD Calls			45	45 VBD calls
12	DLC Upon Freezout ON			0.50
13	DLC Upon Freezout OFF			0.00
14	Time-Slots in Config			120
15	Nibbles in Config			62
16	VBR		Enable / Disable	Enable	Enable
17	Time Slot 0	C		Transparent	Transparent
18	DOM		Enable / Disable	Disable	Disable
19	Noise (adaptive)		Measure: Enable / Disable Inject: Enable / Disable	Measure: Enable Inject: Disable	Measure: Enable Inject: Disable
20	CCPU		Enable / Disable	Enable	Disable if not equipped
21	Alarm Extension	C	Per Bit Stream / Per Time Slot	Per Bit Stream	Per Bit Stream
22	SIG (SCPU)	C	Enable / Disable	Disable	Disable
23	Speech Detector			Second threshold	Second threshold
24	Fax Compression	C C	Enable / Disable with/w.o. FEC, with/w.o. V.17	Enable without FEC, with V.17	Enable without FEC, with V.17
25	Message Interleaving	C	Enable / Disable MSGR(T) / MSGR(T)/N	Disable MSGR(T) / MSGR(T)/N	Enable MSGR/N, MSGT/N
26	Multi-Frame On Bearer	C	Enable / Disable	Disable	Disable
27	Bit Stream In Config			00-03, bearer
28	Bearer Monitor	C	Enable / Disable	Disable
29	Bearer Starting TS			1
30	Bearer Number Of TS			31
31	Clocks Config			Str0

Appendix A2

Appendix A2 DCME History Form

Site

DCME

Date	Item	Description of change	Reason	Initias

Appendix A3

DCME Summary Table

No.	Bearer		Facility	MCI Type	MCI DCME	MCPU S/W ver	Trunk Group
1	REIMS-SAJ	30N230	CBL	DTX-240F	XBF	7X.40	458
2	REIMS-POT	30N220	CBL	DTX-240F	XCQ	7X.40	516, 517
3	REIMS-POT	30N230	CBL	DTX-240F	XDH	7X.40	456, 703
4	REIMS-POT	30N240	CBL	DTX-240F	XCP	7X.40	1384, 1385, 1386
5	Bagnolet-POT	30N240	CBL	DTX-240F	XBW	7X.40	415, 473
6	Bagnolet-DMH	30N210	CBL	DTX-240F	XCJ	7X.40	418
7	Pastourelle-SAJ	30N210	CBL	DTX-240F	XBH	7X.40	1270
8	Pastourelle-POT	30N210	CBL	DTX-240F	XDQ	7X.40	706, 1312
9	Pastourelle-POT	30N230	CBL	DTX-240F	XCJ	7X.40	528, 704
10	Pastourelle-POT	30N250	CBL	DTX-240F	XCJ	7X.40	468, 469

No.	PTT Type	MCPU S/W ver	Fax Demod.	V.17	Reconfigured	Remarks
1	DTX-240F	7X.40	On	On	10/29/97
2	DTX-240F	7X.40	On	On	10/29/97
3	DTX-240F	7X.40	On	On	10/29/97
4	DTX-240F	7X.40	On	On	10/29/97
5	DTX-240F	7X.40	On	On	11/25/97	Measured from 11/17-
6	DTX-240F	7X.40	On	On	11/25/97
7	DTX-240F	7X.40	On	On	11/25/97
8	DTX-240F	7X.40	On	On	11/26/97
9	DTX-240F	7X.40	On	On	11/26/97
10	DTX-240F	7X.40	On	On	11/26/97

Appendix B1

ECI DCME Contact Information

Firmware Upgrade

Firmware Upgrade & Technical Support (Israel)
Technical Assistance Center
ECI Telecom Ltd.
30 Hasivim Street
Petah Tikva 49130
Israel
Tel +972-3-92666618 / 9287075
Fax +972-3-9241386
E-mail DCME_TAC@ecitele.com

Technical Support (US)

Gary F Chevier
ECI Telecom, Ltd.
TX
Tel +1-817-329-2060
MCI Worldcom Mail: Gary F Chevier

Technical Support (Israel)

Haim Guata
Director, product marketing, DCME
ECI Telecom Ltd.
Petah Tikva 49133
Israel
Tel +972-3-9266628
Fax +972-3-9244205
E-mail Haim@smtplink.ecitele.com

Appendix B2

MCI Worldcom Operations Contact
Information

Dominguez Hills

Kim Markiewicz, Manager
Phone: +1-310-894-4046
E-mail: Kim.Markiewicz@mci.com

San Antonio Junction

Herbert Muniz, Manager
Phone: +1-210-554-3280
E-Mail: Herbert.Muniz@mci.com

Pottstown

Garry Stauffer, Manager
Phone: +1-610-970-6070
E-mail: Garry.Stauffer@mci.com

West Orange (Crystal Lake)

Robert Pruett, Manager
Phone: +1-201-669-6950
E-mail: Robert.Pruett@mci.com

Pompano Beach

Luis Abad, Manager Phone: +1-954-283-3575
E-mail: Luis.Abad@mci.com

Appendix C

Special Testing Set up Procedure

Test Configuration

1. Decide on the DCME to test

Only one DCME per country can be tested at a time. If there are several DCMEs between MCI Worldcom and the carrier, choose one. One way to decide on the DCME to test is to choose one that has the most items with different settings between both ends.

2. Get the route numbers

In the NDO find all the route numbers (trunk group numbers) that are accommodated in the DCME that you have picked in the previous step. Note the gateway name and the route numbers.
3. Request INMC to set up a special testing route

To set up a special route with the following information: 1) destination country 2) origination number

3) destination number with pseudo country code 4) gateway 5) route numbers.

4. Request IPMS to set up a special test

Request test administrator to run the special test with 12 calls per day.

5. Confirm set up

After the special route has been set up, test it by dialing the number from your telephone and make sure that you hear the ring back tone. If you do not get the ring back tone, report the symptom to INMC.

Appendix D

DCME Configuration Guidelines

To ensure uniformity, it is important that both ends on a route have the same number of FDEM/N cards. Recommendation is 3 FDEM/N cards.

Note	ECI DTX-240F DCMS	Configuration Guidelines
2	Bearer Type	(2 Mbp/s, TS-O Transport)
2	Sig Option	(Disabled)
2	Alarm Extention	(per Bit Stream) if Q.50 is not turned on either side
2	Alarm Extension	(per time slot) if Q.50is turned on both side
1	Adaptive Noise	(Measure Enabled/Inject Disabled)
	Alarms	(Minor on DLC, Auto alarm reset)
	System Side	(Bearer 2M ; Trunk 2M)
1	VBR Option	(Enabled)
	BIT Option	(Running)
	Terminal Options	(PC OPS)
1	CCPU Option	(Disabled) if not equipped
1	CCPU Option	(Enabled) if equipped
1	DOM Option	(Disabled)
1	SPD Threshold	(2nd Threshold)
2	Silence Elimination Option	(Enabled)
2	Fax Compression Status	(Enabled)See Caution 9600 Hardware: V.17 Disabled 14.4K Hardware: V.17 Enabled
2	Message Interleaving Option	(Enabled)
2	Forward Error Correction	(Enabled for Satellite Routes Disabled for submarine cable routes)
	Fax Handlig Capability	60 (Two cards equipped only)
2	Multi-Frame on Bearer	Disabled

Please make sure that if Bearer has to pass through Satellite FEC has to be enabled.

VBD Config	LARGE__CONF
VBD CC Dysnamic Limit	55
VBD CC Max Sim. VBD Serv.	57 (per hour)
DLC Activity Threshold	99
DLC Release Threshold	94
Minimum Bit Rate	3.7 bits
DLC On Hangset	05 seconds
DLC Off Hangset	10 seconds
DLC Upon Data Threshold	LA45 VDB calls

Note:

1 means each side is independent of others.
2 means both sides must have the same option selected.
3 means each side can select independently but result is affected by both options selected. Caution:
* The DTX-240F must be equipped with FTSI?N and FcPa w/ v.iz s/w, FMOD/N FTSI/N and FDEM/N revision cards in order to enable the V.17 (14.4K fax) feature. Please check with far end if they have this configuration.
* V.17-FDEM/N: Please check with far end if they have V.17 Capability. If yes please Enable V.17.
* If far end does not have V.17 Capability, disable V.17.

ECI DTX-240F DCMS
	Bearer Type	(2 Mbp/s, TS-O Transport)
	Sig Option	(Disabled)
2	Alarm Extention	(per Bit Stream) if Q.50 is not turned on either side
2	Alarm Extension	(per time slot) if Q.50is turned on both side
	Adaptive Noise	(Measure Enabled/Inject Disabled)
	Alarms	(Minor on DLC, Auto alarm reset)
	System Side	(Bearer 2M ; Trunk 2M)
	VBR Option	(Enabled)
	BIT Option	(Running)
	Terminal Options	(PC OPS)
1	CCPU Option	(Disabled) if not equipped
1	CCPU Option	(Enabled) if equipped
	DOM Option	(Disabled)
	SPD Threshold	(2nd Threshold)
	Silence Elimination Option	(Disabled)
	Fax Compression Status	(Disabled)
	Message Interleaving Option	(Enabled)
2	Multi-Frame on Bearer	Disabled

VBD Config	LARGE__CONF
VBD CC Dysnamic Limit	55
VBD CC Max Sim. VBD Serv.	57 (per hour)
DLC Activity Threshold	99
DLC Release Threshold	94
Minimum Bit Rate	3.7 bits
DLC On Hangset	05 seconds
DLC Off Hangset	10 seconds
DLC Upon Data Threshold	LA45 VDB calls

MITSUBISHI DX-3000

------------------

This represents 4:1 system gain without a clear channel. Both trunk and bearer interfaces are at E1 (2.048 Mbps) level.

I. Mode Map

Item	Recommended Setting
Trunk interface mode	( 0:1.5M 1:2M ): 1
Bearer interface mode	( 0:1.5M 1:2M ): 1
Multiclique	( 0:Unuse 1:Use ): 0
BC boundary	( 2 - 30 ) :
For Clique-1 Clique-2
Number of AC	( 1 or 2 ) : See Note
Number of IC	( 1 - 216 ) : 120
DSI operation	( 0:Unuse 1:Use ): 1
DSI mode	( 0:32K 1:64K ): 0
Number of BCs for DSI	( 1 - 61 ) : See Note
Overload channel	( 0:Unuse 1:Use ): 1
32K DNI	( 0:Unuse 1:Use ): 0
Number of BCs for 32K DNI	( 1 - 61 ) :
64K DNI	( 0:Unuse 1:Use ): 0
Number of BCs for 64K DNI	( 1 - 30 ) :

Note

If "Number of AC" is 1, "Number of BCs for DSI" should be set to 61.

If "Number of AC" is 2, "Number of BCs for DSI" should be set to 60.

II. DLC threshold

Set DLC threshold:

Time base [sec.]	( .5 / 1 / 2 / 4 / 10 / 30 ) : 10
DLC detection	(0:Encoding sample 1:Freezeout ) : 0
Remote terminal's DLC	( 0:Unuse 1:Use ) : 1
DLC threshold	( occurrence ) : 3.7 Encoding sample ( recovery ) : 3.9 Encoding sample

MITSUBISHI FC-3000

------------------

When used in conjunction with a DX-3000, Fax compression is provided. All

the DX-3000 setting are to be used unless specified below:

Forward Error Correction: ON

Appendix E

Technical Note

Appendix E1 ECI Telecom DTX-240E/F

A. Configuration Change
Subject: Making Configuration Changes Source: ECI Telecom

Although data are saved in the HDD with every option setting change done from OPS, it is recom-mended to reset the terminal after changes have been made. There are “soft reset” and “hard reset” which essentially have the same effect. The “soft reset” is done by pressing the reset button located by the power switch at the left-hand corner of the RT shelf in each terminal. The “hard reset” is performed by turning off and on the power switch. In either case, traffic is interrupted briefly (about three seconds).

Also, execute “GET CONFIGURATION” after configuration change is made. “GET CONFIGURA-TION” loads data from the terminal to the HDD in the PC. “START” command will load the configu-ration data stored in the HDD to the terminal and will reconfigure the terminal. “GET CONFIGU-RATION” does not interrupt traffic, while “START” does interrupt traffic.
For major configuration changes, the traffic should first be switched over to the redundant terminal. However, this switch-over operation is also accompanied by traffic interruption for about five seconds.

Subject: Getting Configuration Reports Source: ECI Telecom

Configuration reports, such as brief config. and complete config. pulls out configuration data stored in the HDD. Therefore, it is recommended to first perform “GET CONFIGURATION” to ensure the current configuration is loaded onto the HDD.

B. Fax Demodulation, V.17
Subject: Fax Demodulation Source: ECI Telecom

DTX-240D and E models do not perform fax demodulation; fax calls are transmitted via ADPCM. The maximum gain for fax calls is 2:1. DTX-240F model does perform fax demodulation (with fax compression enabled) and maximum gain is over 6:1 for 240f.

Subject: V.17 Source: ECI Telecom

In DTX-240F model, if an FDEM (regular) card is installed, the maximum transmission rate is 9.6 kbp/s. If FDEM/N cards are installed and V.17 is enabled at both ends, the maximum transmission rate is 14.4 kbp/s. If only one side is equipped with an FDEM/N card, it must be configured as FDEM (regular), and V.17 for both sides must be disabled. Settings for V.17 and fax compression are independent of each other. To see which type of FDEM cards are installed, type in the following commands:

-Main Menu- -Terminal Conversation- -Configuration- -Others- -Fax- -List-

Subject: FDEM, FDEM/N Cards Identification Source: ECI Telecom

Question: I understand that the Config. Far Report will provide the location of FDEM cards in the form of “01——.” Is there any way to identify whether they are FDEM(regular) or FDEM/N (high rate) cards from the Config. Far Report or the Complete Config. Report? Or by typing any other commands from a terminal? Suppose a DTX-240F contained a combination of regular and high rate cards, is there any way to identify how many of each card type are installed?

Answer: Reference OPS Users Guide pg. 5-76, 77 “Fax Demodulator Configuration” This section describes the FDEM’s and FDEM/N’s configuration information. It displays the type of card and in which location it is. For your quick reference, here are the OPS menu commands that you would type to display to Fax Demod Card Configuration:

-Main Menu- -Terminal Conversation- -Configuration- -Others- -Fax- -List-

Subject: Fax Transmission Speed Source: ECI Telecom

Question: Each DCME at both ends has fax demod. enabled without V.17 option. Test fax calls made via this DCMS show that about 75% of all calls go at 9.6 but 25% go at 14.4. Why do some calls go at 14.4?

Answer: When the DCME with V.17 disabled receives a G.3 fax call which tries to establish a speed of 14.4, it tells the fax terminals to train down to 9.6. This is counted as an “unclassified event” in the Worst Period Report. On the second time, if the fax terminals still tries to send at 14.4, the call is handled by VBD.

The above can be confirmed by first looking at the Fax Report from the OPS. Command (F1), (T)erminal conversation, (R)eport, (S)elect report, (F)ax. Zero should be shown under 14400 Baud since no calls at 14.4 were processed by the fax demod. Second, look at the Worst Period Report. You should see some VBD activities as well as “unclass events” under fax statistics.

C. Message Interleaving

Subject: Message Interleaving Source: ECI Telecom Question: I hear that when changing the message interleaving setting from disable to enable or vice versa, some sort of hardware wiring change is needed. Am I correct? Are there any other items which need special attention, ie hardware modification, when changing their setting? Which items for which models are they?

Answer: No hardware-wiring change is needed. This is an “OPS “ user selected software option. There is one thing that might be worth checking. The older DTX-240 models (early 1990’s) came equipped with Messaging Cards that did not support the message interleaving feature. The Messaging Cards should be of the newer type. Please see example:

Older Cards: These cards only support the “non-interleaved message format.” The option must be set to disable. The front slice on these cards are labeled:

MSGT (message transmitter) MSGR (message receiver)

New Cards: These cards support either “interleaved or non-interleaved message format.” The option is set according to what is required.

Each end of the link must be set the same for the terminals to communicate. For interleaved - enable the option, for non-interleaved - disable the option. The front slice on these cards are labeled:

MSGT/N (message transmitter) MSGR/N (message receiver)

These cards are located in the RT (receive-transmit) shelf of the DTX-240 Terminals.

D. Signaling

Subject: CCPU Source: MCI Worldcom If CCPU is enabled, Q.50 is turned on. If CCPU is disabled, Q. 50 is turned off. Subject: R1 Signaling (SCPU) Source: MCI Worldcom

If SCPU is enabled, R1 signalling (or R2, etc.) is used and dial pulse options and TS-16 bits definitions become pertinent. If SCPU is disabled, R1 signaling is not used, in which case dial pulse options and TS-16 bits definitions are irrelevant.

Subject: Dial Pulse Options Source: ECI Telecom

Question: In the complete configuration output, I see dial pulse options. Could you please explain what these options are used for?

Answer: The DTX-240’s can be configured to support various types of switch-to-switch signaling protocols. The types supported are:

(1)Sigl. #5, 6, 7,
(2)CCITT R1 and R2 Digital,
(3)Dial Pulse Signaling, and
(4)Signaling via clear channels.

The “complete configuration report” displays the parameters of the dial pulse settings. This informa-tion is only relavent if the switch-to-switch signaling protocol being used is “Dial Pulse Signaling”. Dial Pulse Signaling is a signaling protocol that I haven’t seen too often in international applications, however if the application is one that requires the protocol to be supported certain parameters must be defined for it to work properly with the DTX-240 equipment. These parameters are signaling attributes in setting up a call end to end.

As you can see from the “complete configuration report” they are:

MFR (multiframe) Debounce Time(c)
RMFR (remote multiframe) Debounce Time
Dial Pulse Polarity
Dial Pulse Mode
Make Break Select
Blocking Signal

The DTX Terminals must be equipped with the TSIG and RSIG Cards (commonly known as the Transition Signaling Kit) before this signaling protocol can be supported. For information on how to set-up Dial Pulse Signaling, please refer to the OPS User Manual, Chapt. 5, page 5-64.

Subject: DLC Source: MCI Worldcom

Question: I see in one MCI Worldcom terminal that both CCPU and SCPU are disabled. How does this DCME send DLC info to the switch?

Answer: MCI Worldcom uses the relay contact interface called TASI for signaling between DCME and switch. This interface does not appear in option settings.

About the author

Joseph Swanson has over thirty years of experience in the management and design of lar ge scale telecommunications networks. His professional career includes eighteen years with New Y ork T elephone and the past fifteen years with MCI W orldcom, where he is senior manager of the Performance Planning and Analysis or ganisation. Joe received his Bachelor of Science Degree in T elecommunications and Management from the State University of New Y ork and has served on the Electrical T echnology Advisory Committee of the Duchess County Community College, State University of New Y ork. He also holds licenses from the Federal Communications Commission and is a long time participant in the ITU-T Quality of Service Development Group (QSDG), the Network Management Development Group (NMDG), and the Forum for International Irregular Access (FIINA).

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ECI DTX-240F DCMS

Configuration Guidelines

ECI DTX-240F DCMS