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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Alarms, Phones, Aerials, CCTV & Datacomms >> ISDN 2e Fault? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1301386781 Message started by MikeD on Mar 29^th, 2011, 9:19am

Title: ISDN 2e Fault?
Post by MikeD on Mar 29^th, 2011, 9:19am

My employer has a Siemens PABX system which was installed about 5 years ago (before I arrived). There are 3 ISDN wall boxes which are labelled as follows:

ISDN 2e (CH1/2)
NTE8 (CH3/4)
ISDN 2e (CH5/6)

The green LEDs on the CH3/4 and CH5/6 boxes are on but the CH1/2 LED flashes constantly and I'm trying to find out if this is indicating a fault on our system.

BT ran a remote line test and say there is no fault showing, but will charge us if they come out and there is a fault with our equipment. I called the people who maintain our exchange and they think it's BT's problem.

Does anyone know what the flashing green LED means? Is it a fault condition, and if so is it our equipment or BT's?

Thanks in advance,

Mike

Title: Re: ISDN 2e Fault?
Post by Lectrician on Mar 29^th, 2011, 10:03pm

If the first line has it's green LED flashing, it means it is not synced to the PBX - most likely a faulty ISDN line card in the PBX or a faulty cable from the NTE8 to PBX (they are all NTE8's on the wall, even if only ones says so).

Try swapping the RJ45 plug from one line to the other to see if the fault follows. This proves the fault is with you and not BT.

As it is your first line (so lines 1/2), you are likely missing calls?? If you disconnect the BT line from the NTE8 (you are not meant to do this), then the ISDN will failover to the next line. BT may to this their end for you if required.

Title: Re: ISDN 2e Fault?
Post by MikeD on Mar 30^th, 2011, 9:06am

Hi, and thanks for the helpful reply. I swapped the plug as you suggested and the flashing light did indeed follow the line. I will get the people who maintain our system to come out and have a look at the PBX.

My colleagues here tell me that the light has been flashing for many months, but I'm not aware that we've been missing any calls.

Mike

Title: Re: ISDN 2e Fault?
Post by MikeD on Mar 30^th, 2011, 1:23pm

All sorted! The telephone company talked me through disconnecting the faulty line inside the PBX and plugging it in to a spare socket and that has resolved the fault at no cost.

Thanks again! :)

Mike

Title: Re: ISDN 2e Fault?
Post by Lectrician on Mar 30^th, 2011, 4:47pm

Line cards generally come with two ports each, so you likely had 4 ports available, and are only using 3. They have got you to swap the port over, and then re-programmed the equipped lines, possibly remotely.

Title: Re: ISDN 2e Fault?
Post by MikeD on Mar 31^st, 2011, 8:34am

I'm not sure if they've done any reprogramming (they seem pretty clueless to me). Is that necessary after swapping a line?

The unit is a Siemens 3350 which has two ports as standard plus an add-in card with a further four sockets on it.

Mike