Today 2nd Feb 2021 I have solved the problem for my client whose ISDN phone line was down since yesterday

Subject: Today 2nd Feb 2021 I have solved the problem for my client whose ISDN phone line was down since yesterday

Good day from Singapore,

Today 2nd Feb 2021 Tuesday I have solved the problem for my client "Joe Biden LLC" (fictitious company name used) whose ISDN phone line was down since yesterday.

My client is using Singapore Singtel ISDN line with Sangoma FreePBX Phone System 60. Asterisk version is 13.14.0 and FreePBX version is 13.0.191.4.

Yesterday 1st Feb 2021 Monday about 1+ PM Singapore Time, our client notified us that their phone line is down. All their callers are receiving "All circuits are busy." message. By late afternoon, my seniors had rebooted the Sangoma PBX appliance but did not manage to solve the problem.

Today morning 2nd Feb 2021 my boss Edward Joseph Snowden (fictitious name used) remoted into the client's server. After troubleshooting for about half an hour, he thinks the problem may lie with the optical fiber line. He dispatched me onsite to the client's office.

When I was at the client's office, I saw that the Huawei OptiX PTN 905A Router has a red ALARM LED. My boss and team leader Julian Assange (fictitious name used) thinks the problem may lie with Singtel service provider. So I called Singtel business technical service hotline. A Singtel engineer reached our client's office at about 2.30 PM Singapore Time. Using the ISDN phone, he tested the circuit and found no errors. He called me successfully using his ISDN phone and I also called his ISDN phone successfully. The conclusion is that there is nothing wrong with Singtel's circuit. The red ALARM LED was there because there are unused ports, the Singtel engineer explains. If all the ports on the Huawei OptiX PTN 905A Router are used, then there would be no red ALARM LED. So even though there is a red ALARM LED, it is still normal.

Because my boss Edward Joseph Snowden was rushing to another client's site, he left me to do the troubleshooting. With a bit of good luck, I performed a Google search with all the correct key words and found the following the guide, which helped me to solve the problem very quickly.

Reference Guide: PBX Setting for Singapore Singtel ISDN

Link: http://sappology.blogspot.com/2012/12/pbx-setting-for-singapore-singtel-isdn.html

Author: Sap

I shall reproduce his blog post as follows.

[QUOTE=Blogger Sap]

I had a chance to set up a PBX server with my ex company.  It was fun and recently , the server was down. I was called up and out of goodwill , I had a go at it.

The problem was someone upgraded rpm , modules and hence messing up the DAHDI settings.

Server --> Dell

ISDN Card -- > TE110P

Service Provider -- > Singtel ISDN-30

Software used --> AsteriskNow

Asterisk Core --> asterisk-core-1.6.2.24-1_centos5

GUI -- > Freepbx

these are the DAHDI settings (Freepbx)

Framing/Coding : CCS/HDB3/CRC4

Signalling: PRI-CPE

SwitchType: EuroISDN

Sync/Clock Source: 0

Context: from-pstn

*Others that are not mention , leave it as default

For the hardcore users,

# cat /etc/dahdi/system.conf

span=1,0,0,CCS,HDB3,CRC4

bchan=1-15,17-30

dchan=16

loadzone=sg

# cat dahdi-channels.conf

; Span 1: WCT1/0 "Digium Wildcard TE110P T1/E1 Card 0" (MASTER) HDB3/CCS/CRC4

group=0,11

context=from-pstn

switchtype = euroisdn

signalling = pri_cpe

channel => 1-15,17-31

context = default

group = 63

# cat /etc/asterisk/dahdi-channels.conf

; Span 1: WCT1/0 "Digium Wildcard TE110P T1/E1 Card 0" (MASTER) HDB3/CCS/CRC4

group=0,11

context=from-pstn

switchtype = euroisdn

signalling = pri_cpe

channel => 1-15,17-31

context = default

group = 63

Restart dahdi after applying the settings

*******

pri_net & pri_cpe control who acts like the "ISDN Network" and who acts like the "ISDN Customer Equipment". When you connect to a telco provided PRI, you'll want to set to "pri_cpe" *and* set the span in dahdi.conf to take clock from the line because you are customer equipment. If you are plugging your asterisk box into a PBX or something that is not a telco provided, you'll want to be set to "pri_net" because you are pretending to be the telephone network and you want to set the span in dahdi.conf to be timing level "0" to provide clock out onto the line.

*******

Check on dahdi status

From console

# asterisk -vvvr

dahdi show channels

dahdi show status

[/QUOTE]

Using the above guide which I found upon Google search, I found out that the DAHDI settings in my client's Sangoma PBX appliance were WRONGLY set to:

Framing/Coding : CCS/HDB3

Signalling: PRI-CPE

SwitchType: National ISDN 2 ()

Sync/Clock Source: 0

Context: from-digital

Using the above guide which I found upon Google search, I CORRECTLY changed the DAHDI settings in my client's Sangoma PBX appliance to:

these are the DAHDI settings (Freepbx)

Framing/Coding : CCS/HDB3/CRC4

Signalling: PRI-CPE

SwitchType: EuroISDN

Sync/Clock Source: 0

Context: from-pstn

*Others that are not mention , leave it as default

After applying the above settings and restarting DAHDI and Asterisk, I have basically solved my client's problem and brought up their phone line. I did not even touch the configuration files as mentioned above. Everything I have done was configured through the FreePBX GUI. I was so happy to have solved my client's problem and brought up their phone line by the time I left their office.

Mr. Turritopsis Dohrnii Teo En Ming, 42 years old as of 2nd Feb 2021 Tuesday, is a TARGETED INDIVIDUAL living in Singapore. He is an IT Consultant with a System Integrator (SI)/computer firm in Singapore. He is an IT consultant.

REFERENCES

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[1] http://lists.digium.com/pipermail/asterisk-users/2021-February/295692.html

[2] http://lists.linuxfromscratch.org/pipermail/lfs-chat/2021-February/029194.html