GSM Gateway Installation

21 Sep.,2023

 

Mike's PBX Cookbook

GSM Gateway Installation

Index:

Introduction:

More and more sites are installing GSM gateways for cell phone access. The gateway allows calls to cell phones to be charged the >on net price, which in most cases, is significantly less than calling the same cell phone from the PBX's normal city trunks. There are two ways to accomplish this, one analog and one digital. The analog solution is less expensive to purchase and install, but is prone to disconnect problems. The digital solution is more expensive and harder to program, but offers reliable disconnect and routing advance options.

When planning to install a gateway, it is always best to keep the antenna cable as short as possible. It is also a good idea to keep as much room as possible between the gateway antenna and other antennas. If two antennas are mounted to close to each other, and in this case, satellite dishes count as antennas, they can interfere and lower the signal strength to both even though they are operating on different frequencies. Since telephone switches tend to live in basements and antennas like high places, you could end up with a very long cable run between the two. In this case, an option would be to use a fiber run with a fiber modem on each end like a FiberPlex FOI-4048.

Analog Gateway:

The analog option is the simplest to install since it integrates through a normal loop start trunk. Except for the route number and designation, you can copy the existing analog backup trunk route and trunk programming. Just make sure that SUPN (NO) when you build the trunk in LD 14. There is no disconnect or answer supervision returned to the Meridian from these devices. From here, go to Switch Programming part 2 (BARS/NARS) for the next step.

Digital Gateway:

The preferred GSM gateway of choice is the 2N BlueStar in most cases. Larger and smaller units are available from the same manufacturer, but they all program the same. The devices use a EURO-ISDN interface. To add this to a small switch, you will need the following:

  • NTBK50    E1 PRI card
  • NTAK20    Clock controller if this is the first digital trunk in the cabinet.
  • NTBK51    Downloadable D-Channel (DDCH) daughterboard
  • NTBK05DA    120 ohm Twisted pair hang-off cable.
  • Assorted adaptors and connectors.

It is always best to go through your vendor and request a system expansion just to ensure that you get all of the parts required and that your system is at an acceptable software release level. Also, if you have a large system (61C or 81C) you will have interface cards other than the ones listed above.

Switch programming Part 1 :

1. Set thresholds if this is to be the first PRI2 span in the system.

Otherwise, just display to verify the proper values are present. Since the default values work, this should not be a problem. This is an example from a 61C. If you get an error, it does not exist and you have to build it. Note, there is no clock reference set since there is no digital link to the telephone company. The GSM will be the slave.

>LD 73
REQ: NEW
TYPE: DDB
PREF <CR>
SREF <CR>
TRSH 0
REQ: END

>LD 73
REQ: PRT
TYPE: DDB
CC DATA NOT 1.5MB

TRSH 00
RALM 3
BIPC 2
LFAC 3
BIPV 3 2
SRTK 5 30
SRNT 15 3
LFAL 17 511
SRIM 1
SRMM 2
REQ: END
>

2. Add a PRI2 loop to the switch.

LD 17
REQ: CHG
TYPE: CEQU
DDCS <CR>          enter past everything until you reach:
TDS <CR>
CONF <CR>
DTDT <CR>
DLOP <CR>
PRI2 LL            LL= loop number, or slot number in small systems
 <CR>              to the end
REQ: END
>

3. Add a D-Channel controller.

LD 17
REQ: CHG
TYPE: ADAN
ADAN NEW DCH X where X= the DCH number. In a small system,            make it the same as the cardslot number.

CTYP MSDL

[DNUM 6    or  same as the DIP switch selected number in large systems
CDNO 3]        same as slot number in small systems. Only one of these two
               prompts will show on a switch depending on size.
PORT 1         0 - 3, will always be '1' on 11C/Succession Media Gateway
DES GSM_GATEWAY
USR PRI
DCHL LL        Loop number programmed in step 2
OTBF 32
PARM RS422 DTE
DRAT 64KC
CLOK EXT
IFC EURO
CNTY NET       Country code NET= ETSI network side protocol
PINX_CUST 0
ISDN_MCNT 300
CLID OPT1
PROG NCHG
CO_TYPE STD
SIDE NET       The gateway is always USR, Meridian is always NET
CNEG 1
RLS ID
RCAP COLP
MBGA NO        default value
OVLR NO        default value
OVLS NO        default value
T310 120       default value
INC_T306 120
OUT_T306 120
T200 3         default value
T203 10        default value
N200 3         default value
N201 260       default value
K 7            default value
ADAN <CR>

REQ END
>

4. Activate ISDN for the customer if not already there

LD 15
REQ: CHG
TYPE: NET_DATA
CUST 0 
OPT
AC2
FNP
ISDN YES
<CR>     to the end
REQ END
>

5. Build the trunk route.

>LD 16
REQ NEW
TYPE RDB
CUST 0
DMOD 
ROUT 3
DES GSM_GATEWAY
TKTP TIE
ESN NO
CNVT NO
SAT NO
RCLS EXT
VTRK NO
DTRK YES
BRIP NO
DGTP PRI2
ISDN YES 
MODE PRA
IFC EURO
CNTY NET
SBN NO
PNI 00000
CTYP UKWN
INAC NO
CPFXS YES
SDID NO
DAPC NO
INTC NO
DSEL VOD
PTYP DTT
AUTO NO
DNIS NO
DCDR NO
IANI 
ICOG IAO
SRCH LIN
TRMB NO
STEP 
ACOD 78
CLEN 
TCPP NO
TARG 01
BILN NO
SGRP 
OABS 
INST 
ANTK 
SIGO STD
ICIS YES
OGIS YES
PTUT 0
CNTL 
DRNG NO
CDR YES
INC NO
LAST NO
QREC NO
OAL YES
AIA NO
OAN YES
OPD NO
NDP EXC 0
NATL YES
SSL 
CFWR NO
IDOP NO
VRAT NO
MUS NO
PANS YES
FRL 
OHQ NO
OHQT 0
CBQ NO
AUTH NO
TTBL 0
ATAN NO
PLEV 2
OPR NO
ALRM NO
PECL NO
DCTI 00 
TIDY 
CCBA 
ARDN 

MEM AVAIL: (U/P): 2578619 USED UP: 368742 83678 TOT: 3031039 
DISK RECS AVAIL: 255 
RAN RTE AVAIL: 500 USED: 0 TOT: 500
REQ END
>

6. Add the trunks.

Note: one can build the same number of trunks as SIM cards in the gateway rather than relying on the congestion reason to be returned by the gateway since there are several things that have to be right for that to happen correctly.

>LD 14

REQ NEW 8      8 SIM cards fitted, so build 8 trunks with a single command.
TYPE TIE
TN 3 1
DES GSM
PDCA 1
PCML A
CUST 0
NCOS 0
RTMB 3 1
B-CHANNEL SIGNALING 
INC 
MNDN 
TGAR 1
AST NO
CLS CTD DTN WTA LPR APN THFD XREP BARD P10 VNL
TKID 

NEW TRK TN 003 01 RT 3 MB 1 
NEW TRK TN 003 02 RT 3 MB 2 

The above repeats for each trunk the system builds. In this example, there would be seven more.

REQ END
>

Hardware link installation:

The hardware link can be over several types of media and use a variety of facilities. The most viable options are in the table below.

MediaConsiderations Two 75 ohm coaxial cables Copper solution least susceptible to electrical noise, but expense to run. Two pair of category 5 twisted pare station cable.Readily available, but also most susceptible to electrical interference. Fine forshort runs away from noise sources. Two individually shielded or screened pairs of category 3 twisted pair cable.120 ohm preferred option. This is only marginally better than cat 5 cable for noiseprotection. Optical fiberLeast susceptible to noise but requires media converters on each end. This may be a good choice for long runs between buildings or sites.

The sample below is based upon using a fiber link with FiberPlex model FOI-4048 media converters at each end since it is the most complex and, therefore, the most likely to be a source of confusion to someone who has not done one before. The switch breaks out on a 9-pin D-connector. A 9-pin to RJ45 adaptor is used to go to cat 5 cable, and then an RJ45 to 15-pin D-connector adaptor (provided with the FOI-4048) is used to interface the FOI-4048. The Bluestar uses the same FOI-4048 to RJ45 arrangement, but the other end of the cat 5 straight RJ45 to RJ45 patch cable plugs directly into the Gateway.

The arrangements in the table connect unused pins to empty socket positions. This ensures that nothing can short out in service. It is recommended that the user just slide the adaptor pins into the connector without the body or hood, or in the case of the 9-pin adaptor, the female wire ends into the pins of the connector on the NTBK05DA cable to prototype the connections. When everything works, finish assembling the connectors and attach the hoods. This will allow for maximum flexibility without having to risk damaging a misplaced pin in the attempt to move it.

Three green LEDs on the FOI-4048 indicate that transmit and receive leads are correct. Since E1, like T1, is an AC protocol, T/R reversals are not an issue. IfLINE RX does not illuminate, transmit and receive fibers are transposed someplace along the way. If LINE RX is dark, then just swap 1 & 9 with 3 & 11 at the DA-15 to RJ-48 adaptor.

Adaptor Wiring DA-15 PINCOLORUSERJ-48 PIN 9BIN1 1OIN2 5BkGND3 11ROUT4 3GOUT5 13YGND6 15Br 7 7W 8 DB-9 FROM SWITCH 1W 8 2GIN5 3RIN4 4BrIN7 5YGND6 6BOUT1 7OOUT2 9BkGND3

Note: the span has to be activated on both ends before the FOI-4048 indicators can be used for troubleshooting.

Connect the E1 from the Meridian to PRI 1 on the gateway face. Connect a computer to the RS-232 port and load the program from the provided CD following the instructions in the BlueStar manual.

Before connecting power to the BlueStar, ensure one of the two conditions below are being met:

  1. The Gateway is in its final position and has all antenna connections in place to allmodules and the main antenna is connected to the antenna splitter.
  2. The Gateway has all 8 of its GSM module boards unplugged and the 3 common control boardsare in place as received from the manufacturer.

Even thou the GSM boards are hot switchable, this ensures that the transmitters in the GSM boards are not transmitting into an open circuit. The prototype system used option 2 to verify pin connections in the telephone room before moving it to the final location in another building. This eliminated any cabling problems from confusing the issue.

This is also the time to install SIM cards. Each GSM adaptor card has two modules. Each module can carry one call at a time and can use up to 4 SIM cards. SIM 1 is closes to the edge connector. The first module (GSM1) uses the SIM cards along the left edge of the card and GSM2 uses the SIM cards along the right. Cards count right to left as you look at the front of the gateway. The SIM holders slide forward, then tip up to accept the SIM. Reverse the procedure to lock the SIM in place.

NOTE: PIN must be disabled on all SIM cards or all SIM cards must have the same PIN.

GSM Gateway Programming Part 1:

The sample setup shown in the BlueStar manual on page 67, section 10.5.3.1 works with the above switch programming; the factory default as received will not. The important items are in the top row. ISDN PRI port type: must be TE. Synchronization: must be Slave. These are the only two fields that must be changed to get the span to come up upon activating the Meridian end.

Switch programming Part 2:

1. Activate and load the DDCH controller. This example uses DCH 3

>LD 96
.ENL MSDL 3 FDL This forces the download
......................................................
[multiple lines of dots from the system]
......................................................
OK
.DIS AUTO 3
.DIS DCH 3      Prepares for a clean start.
.****

>LD 60
.ENLL 3         Start the span. 

If the gateway is connected and powered, it will come up and you will have 3 green LEDs on each FOI-4048 and both the layer 1 and layer 2 green LEDs on the gateway. The Gateway layer 3 LED only lights when a call is in progress.

.STAT 3
PRI 2 LOOP 3 - ENBL
REF CLK:DSBL
SERVICE RESTORE: YES
ALARM STATUS: ACCEPTABLE
CH 01 - IDLE TIE VOD *    CH 02 - IDLE TIE VOD *
CH 03 - IDLE TIE VOD *    CH 04 - IDLE TIE VOD *
CH 05 - IDLE TIE VOD *    CH 06 - IDLE TIE VOD *
CH 07 - IDLE TIE VOD *    CH 08 - IDLE TIE VOD 
CH 09 - UNEQ              CH 10 - UNEQ
CH 11 - UNEQ              CH 12 - UNEQ
CH 13 - UNEQ              CH 14 - UNEQ
CH 15 - UNEQ              CH 16 - UNEQ
CH 17 - UNEQ              CH 18 - UNEQ
CH 19 - UNEQ              CH 20 - UNEQ
CH 21 - UNEQ              CH 22 - UNEQ
CH 23 - UNEQ              CH 24 - UNEQ
CH 25 - UNEQ              CH 26 - UNEQ
CH 27 - UNEQ              CH 28 - UNEQ
CH 29 - UNEQ              CH 30 - UNEQ
CH 31 - DCH 3 
.****

>LD 96
.ENL AUTO 3
OK
.****

Since we only added 8 trunks for the 8 SIM cards installed, we get the above status display as expected. To test the span, USR must include MTC to use the following:

>LD 96
.ENL MSGI 3
.ENL MSGO 3

DCH 3 UIPE_OMSG CC_SETUP_REQ REF 00000003 CH 3 8 TOD 11:30:58 CK A3FAA57D 
PROGRESS: CALL IS NOT END TO END ISDN 
PROGRESS: INTERWORKING WITH PRIVATE WORK
CALLING #:2107202003 NUM PLAN: E164 TON: NATL 
CALLED #:6984603661 NUM PLAN: E164 TON: UNKNOWN 

DCH 3 UIPE_IMSG CC_REJECT_IND REF 00000003 CH 3 8 TOD 11:31:00 CK A3FAAE70 
CAUSE: #27 - DESTINATION IS OUT OF SERVICE 

.DIS MSGO 3
.****

>

The above is in a reduced typeface so the line shows as it does on the service terminal. Since the SIM cards were not installed at the time of the above test, it is as expected for an in service ISDN line to the Gateway with no working modules available. From this point, it is all just call processing.

2. Change the BARS routing to select the route list containing the GSM gateway trunks.

The prototype was brought up with a little trick that allowed testing without interfering with normal call processing. An unused cell provider code was selected and a special digit manipulation table was built that deleted the first 3 digits and inserted the first the digits of the provider of the SIM chips to be tested. People who dialed the normal number went out the local trunks as normal. This allows unlimited time for testing without user inconvenience. In this case, 691 will be dialed to test 698 numbers.

a. First, display the working SPN:

>LD 90

REQ PRT

CUST 0
FEAT NET
TRAN AC1
TYPE SPN

SPN 6

SPN 6
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

REQ OUT
CUST 0
FEAT NET
TRAN AC1
TYPE SPN

SPN 6             Must be removed first or it will cause a conflict

SPN

REQ NEW
CUST 0
FEAT NET
TRAN AC1
TYPE SPN

SPN 694            Most used carrier, so first back in
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 690
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 691
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 692
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 693
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 695
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 696
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 697
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 698
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 699
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 60
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 61
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 62
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 63
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 64
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 65
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 66
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 67
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN 68
FLEN 0
RLI 4
SDRR NONE
ITIE NONE

SPN

REQ END
>

b. Next build the new route for GSM calls. For our example we will use route list 12 and DMI 10 for our test access.

>LD 86
REQ NEW
CUST 0
FEAT DGT
DMI 10
DEL 3
ISPN
INST 698
CTYP NCHG

REQ NEW
CUST 0
FEAT RLB
RLI 12
ENTR 0
LTER
ROUT 3             Our span to the GSM
TOD 0
TOD 1
TOD 2
TOD 3
TOD 4
TOD 5
TOD 6
TOD 7
TOD 
CNV
EXP
FRL 0
DMI 10
FCI
FSNI
BNE
SBOC RRA           Reroute all, only works on ISDN spans
IDBB
IOHQ
OHQ
CBQ
ENTR 1
LTER
ROUT 1             Local overflow trunks
TOD 0
TOD 1
TOD 2
TOD 3
TOD 4
TOD 5
TOD 6
TOD 7
TOD 
CNV
EXP YES
FRL 0
DMI 2
FCI
FSNI
BNE
SBOC
IDBB
IOHQ
OHQ
CBQ
ENTR 
ISET 1
NATL
MFRL 0
OVLL

REQ END
>

c. Change the test entry to point to the new GSM route list

>LD 90
REQ CHG
CUST 0
FEAT NET
TRAN AC1
TYPE SPN

SPN 691
FLEN
ITOH
RLI 12
SDRR
ITIE

SPN

REQ END
>

GSM Gateway Programming Part 2:

1.    Basic Settings:
Set the correct number of digits to be dialed for a cell phone call. If the dialing plan is not uniform, the minimum and maximum number of digits will be different. Warning, the factory makes a special note that maximum number of digits must be equal or greater than the minimum. Reverse these two, and you have unspecified behavior. You may leave the remaining entries at default.

2.    Assignment to GSM groups:
Assign all of the SIM cards from a provider to one group. Each provider must have his own group. It is best to assign both SIM cards on a GSM card to the same group. This is just for ease of administration; it is not an operational requirement.

3.    GSM Outgoing groups:
Normal application of one SIM per module works fine with the defaults. Change this only if you have multiple SIMs per module and you want to distribute usage evenly.

4.    GSM Incoming Groups:
It is recommended that you reject all incoming calls, although they can be accepted and/or routed to the operator.

5.    Network List:
This is where you tell the gateway which module to use for each possible called number it will receive. When you click on the ADD button, a small window will open which will allow you to enter the numbers for that carrier.

6.    LCR:
The default covers network 1 24/7. If you have additional carriers and groups, you will need to add similar entries for Network 2/group 2, network 3/group3 etc.

Cutover:

When testing is complete, redirect live traffic to the gateway:

1. Change the route list:

>LD 86
REQ CHG
CUST 0
FEAT RLB
RLI 12
ENTR 0
LTER
ROUT    
TOD 
CNV
EXP
FRL 3              Change to the desired restriction level
DMI 0              Remove the test DMI
FCI                <CR> to the end

REQ CHG
CUST 0
FEAT NET
TRAN AC1
TYPE SPN

SPN 694            Repeat for each active provider
FLEN
ITOH
RLI 12
SDRR
ITIE

SPN 
REQ END
>

END OF PROCEDURE!

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