isdn wiring query

dilbert_ie

Hi,

I am considering having ISDN installed into my home (due to geographical reasons and distances from exchanges etc)

The eircom line arrives to the corner of my house where it meets the internal wiring. My house has 5 telephone extensions and I require the ISDN TA to be placed in the office where there is an extension.

3 pairs of wiring are used for the phone wiring, The burgalar alarm gains priority on the standard line and can dial out, the wiring was modified to accomdate this. In theory two more numbers can be brought into the house.

My queries are:

Can an ISDN TA be placed in the office using the existing wiring?
If so will I be able to ramp up to 128 when the phone is now being used and ramp down to 64 when it is being used? i.e. Can the analog line on the TA be patched back in to the telephone wiring

Does the Office need to be the master socket? Not sure which extension is.

Has anyone had ISDN installed under a similar scenario as above?

Thanks

Liam

De Rebel

I'm assuming that you are ordering eircom high speed rather than the traditional eircom basic rate isdn product.

When eircom install your ISDN they install a box on the wall, known as the ISDN plug and play box. The eircom connection is terminated in this box, and there are four outlets, 2xRJ45 (for digital connections) and 2xRJ11 for analogue connections. There are about 5 different ways of catering for your scenario from here.

An average eircom engineer would like to stick that box insde your front door and run. I almost always specify that the box is put in the same place as the computer, for eas of connectivity and for diagnostic purposes. The connection from your TA to the eircom box must be 8 wire (e.g CAT 5) standard phone wire is not adequate.

Your situation, with a requirement for both 64k and 128k access, 5 extensions and an alarm requires a bit of thought.

SO what usually happens.... The box goes on the wall in the room where the PC is, the eircom engineer extends the incoming eircom line to this point. He then uses the original telephone extension wiring from this point (assuming that there was an extension there previously) to link one of the analogue ports back to the original point of entry of the eircom line, and thus connects the analogue port to all of the original extensions. So we now have the box on the wall with two ports in use, the TA in the computer linked to one, and the original telephone wiring linked to the other. You can utilise the second analogue port by connecting an analogue handset to it, thus having two voice lines active.

Another possibility would be to ditch all the extensions and get a DECT cordless, possibly with more than one handset.

There a number of variations of the above possible. Go see one of the boxes and read the eircom booklet that comes with it. A bit of thought and planning at this point could allow you to maximise your benefits from the ISDN service.

Regarding the other question: If so will I be able to ramp up to 128 when the phone is now being used and ramp down to 64 when it is being used?

Switching between 64K and 128K: Manual switching: Assuming that you are using windows, this is more easily achieved if you are using a modern version of windows (i.e. XP is a no brainer, 95 is not). Automatic switching-Dynamic Bandwith Allocation: Software dependent, I've only ever seen it working successfully in server environments. Automatic switching- Call Bumping: Hardware and software dependent, and I have never seen it working.

Hope this helps. One of these questions where a writtne response is about the most difficult way to clearly answer your questions.

Red Alert

I've a monitored alarm on the ISDN box. It's a standard Aritech panel with integrated communicator - just make sure you tell your alarm company if it's going on or off line as it may register a fault.

jwt

Did some work for a client at his home address and in the process had to disconnect the ISDN line while moving the ISDN box.


Big mistake...alarm registers a fault, I reconnect the ISDN line in the new location and the alarm stops beeping.

Thats OK say I to myself and off I toddle, a good days work done.

Following monday displeased customer regales me with the saga of alarm company ringing to confirm whether this is a fault, customer has forgotten secret password and the fun begins.

Anyway as mentioned above the two rj45 connectors are used for the ISDN TA (just one per TA regardless of 64k or 128k connection thats taken care of by your software) and the analogue output is just two screw crimp connections (Molex type) and the two wires act and behave just like an ordinary analogue line, can be split extended excetra.

Regards

JWT

dilbert_ie

Thanks for the info,

Will probably order the ISDN, the clause about wiring taking longer than 1.5 hrs(terms and conditions no. 12) being billable is a slight worry.

The ability to bump up and down from 64 to 128 is kind of essential and hopefully is doable.

One of my colleagues apparently has managed to install ISDN under a similar scenario (after a bit of rewiring on his part) . Hopefully between ourselves and Eircom we will cobble together a solution.

I am hoping that Eircom can hijack a pair of the original wiring in the house to bring ISDN to the office extension, having to install new wiring is a nightmare not worth considering.

Will post the wiring solution if we get it to work.

Red Alert

You'll just need 4 pairs from the 'main socket' at the minute to the office. Two will be unused at the mo' unless you've got 2 phones in the office. What'll they'll do is bring the ISDN into the office on one pair and take the analogue out on the other. You can then also plug a phone into extension 2's socket on the box and you've got two voice lines. (When you're not using the net of course - but it's first come first served so it doesn't matter which phone is in use or anything, the only restriction is two channels in total at any one time!)

Giblet

You engineer will ring to tell Eircon Phonewatch that you are disconnecting the line, of course when my engineer did this, the garda came around and seen two guys messing with wires at the front door

The engineer needs to know where the first connection of the phone is, bascially the box where it comes in from the outside usually near the front door.

When he is wiring up the ISDN box, make sure he doesn't leave wires hanging out of it, like mine did. Had loads of problems, until I finally rewired it neatly and placed all the wires in the proper places. Also make sure ALL your phone extensions work.

dilbert_ie

Ordered ISDN last Wed and they installed it Thu !

They rewired the extensions to bring the unused green/white into the office directly i.e no other ext can use it.

The alarm was ok as it was using the orange/white pair , which was also being used by the main land line number.

Surfing quiet happily at 64 with a 3com isdn pro TA, haven't experimented with 128 yet.