How do I test ISDN lines?

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Jax

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#165763 19-Feb-2015 20:57

I have a job to install ISDN BRA lines and to route them through from demarc through to a patch panel a few hops away.
I assume the telco will install to demarc and test the lines there - is there some way to test the line once patched through to its final location?

Termination will be RJ45, and I have an ethernet/RJ45 tester & POTs phone if it helps:
http://www.cdlnz.com/index.html?do=viewproduct&p=NC700&code=LT-RJ3

Cheers

ubergeeknz

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#1242591 19-Feb-2015 21:00

Yes - with an ISDN tester, and the knowledge to be able to use one.

If it tests OK at the demarc, it's unlikely you'll cause problems after that point. In every install I've been involved with, the telco will use existing building wiring to take it where it needs to go and provide a demarc where you want it.

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coffeebaron

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#1242670 19-Feb-2015 22:21

What's an ISDN? Is this some fancy new technology that will one day replace VoIP? Lol

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#1242710 20-Feb-2015 00:14

Insanely Sweet Data Network. All the cool kids are getting it installed!

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sbiddle

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#1242730 20-Feb-2015 06:17

coffeebaron: What's an ISDN? Is this some fancy new technology that will one day replace VoIP? Lol

The irony of VoIP is that is that while it's a perfect replacement for a regular POTS line, it's not a full replacement for ISDN. One of the big uses of ISDN is broadcast because you get full separation between RX and TX channels.

Jax

92 posts

Master Geek

#1242793 20-Feb-2015 08:54

Yes this is for Broadcasting, so they have some bespoke requirements.

The venue is large and sprawling, so I am unsure if the installer will take the circuit to where it need to go (it may be laborious)

Sounds like it'll have to be best effort!

seoras

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#1253598 8-Mar-2015 22:06

ISDN is pretty specialised and incompatible with POTS (plain old telephone systems) or ethernet (even though it's RJ45 presented).

You could browse on trademe for old 2nd hand ISDN kit.
A telephone or a router would be handy for checking layers 2 & 3 on the BRI.
Here's one at $49
http://www.trademe.co.nz/computers/networking-modems/routers-firewalls/auction-854839887.htm

I worked for Cisco in the mid-90's as an IOS developer working on their ISDN & PPP code.
If you plug that router in and get a terminal line onto it you can check the status of the connection at layers 2 & 3.

Looking back I wish I'd added to the CLI in IOS the callback function I added to the Spider ISDN router before I left them to join Cisco.
Can't believe ISDN is still in use today!

Jax: I have a job to install ISDN BRA lines and to route them through from demarc through to a patch panel a few hops away.
I assume the telco will install to demarc and test the lines there - is there some way to test the line once patched through to its final location?

Termination will be RJ45, and I have an ethernet/RJ45 tester & POTs phone if it helps:
http://www.cdlnz.com/index.html?do=viewproduct&p=NC700&code=LT-RJ3

Cheers

sbiddle

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#1253655 9-Mar-2015 07:26

seoras:
Can't believe ISDN is still in use today!

ISDN is still a fantastic technology. The TX/RX isolation means this is perfect for so many uses beyond regular telephony including the broadcast industry where it's still the norm for things such as radio commentaries of sporting events, and there are plenty of ISDN lines around the country used for radio station backhaul and other uses such as connections for repeater sites for land mobile radios.

In the early 90's Telecom got pretty close to rolling out ISDN as the primary access method to replace POTS lines. We literally would have ended up being one of a handful of countries in the world following behind Germany to do this.

old3eyes

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#1253673 9-Mar-2015 08:37

sbiddle:
seoras:
Can't believe ISDN is still in use today!

ISDN is still a fantastic technology. The TX/RX isolation means this is perfect for so many uses beyond regular telephony including the broadcast industry where it's still the norm for things such as radio commentaries of sporting events, and there are plenty of ISDN lines around the country used for radio station backhaul and other uses such as connections for repeater sites for land mobile radios.

In the early 90's Telecom got pretty close to rolling out ISDN as the primary access method to replace POTS lines. We literally would have ended up being one of a handful of countries in the world following behind Germany to do this.

Agree. ISDN leave SIP trunking for dead as far as implementation goes. basically in 99% of cases it just works where as SIP trunks 50% .. Where ISDN falls down is the monthly costs in that camp SIP trunking wins..

Regards,

Old3eyes

chevrolux

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#1253686 9-Mar-2015 09:00

All you will need to do is plug the NT once you have patched it through. You will see the sync light go solid green - much like a DSL router. The only thing that doesn't test is whether or not the line is actually programmed up with a number.

An ISDN butt phone is an extremely expensive piece of kit so I just carry around an NT Plus which is essentially an 'ATA' and gives an analogue port to test on.

Edit: I'm surprised Chorus didn't patch it through to where you want it - obviously want asked for. We would get jobs all the time to shift ISDN around the courthouse for their conferencing kit.

sbiddle

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#1253689 9-Mar-2015 09:06

chevrolux:

Edit: I'm surprised Chorus didn't patch it through to where you want it - obviously want asked for. We would get jobs all the time to shift ISDN around the courthouse for their conferencing kit.

Yeah.. it's the norm for Chorus to install the NT exactly where it's required rather than at a demarc, but presumably this wasn't requested so wasn't done.

nitrotech

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#1253716 9-Mar-2015 09:37

I see a number of comments about ISDN being the preferred method for broadcast content delivery but can I tell you this is simply not the case.

The preferred method to broadcast is IP via a comrex bric

ISDN is still used where it's been installed mainly because it makes use of legacy gear and frees up the bric's for other broadcasts (but the quality is pretty poor) - the broadcaster still pays a monthly cost for the ISDN line where it's installed and where it's only used a few times a year it doesn't make financial sense.

ISDN hasn't been used for radio backhaul either for quite some time - again IP and satellite DVB are the main methods of distribution.

When the wideband lines were disestablished in the mid/late 90s they were replaced by ISDN but that gear was all ripped out by 2000 and replaced by Kordia proprietary IP links and replaced again by sat/ip around 2010.

Perhaps RNZ still operate some ISDN but for commercial stations they've moved on.