ISDN, PSTN, Broadband...

brianmc

Hi folks,

I'm trying to establish some options for a customer.

They have an ISDN line with 2 numbers on it. Their offices are hosted by a third party who are reluctant to assist with any network infrastructure changes or allow any new lines into the building.

The customers internet connection is provided by a link from the organisation that is hosting them - firewalled, etc.

Our customer would prefer to have their own broadband connection for various organisational and technical reasons.

So... getting a new line installed is not an option. Also, they need to keep 2 phone lines...

I am wondering about the possibility of switching the ISDN line to two PSTN lines so that we can get DSL or efibre on one of them.

The ISDN box and their PBX is in the customers office. The uplink to the ISDN box is a 4 core telephone cable that is patched through from the host organisations infrastructure.

So, those who know more than me about this stuff... do you think it would be feasible for eircom to use these 4 cores as 2 PSTN lines without having much (any) interaction with the host organisation?

Boskowski

There may be contractual reasons but from a tech point of view you don't need to switch away from ISDN to get DSL. Its the same two copper wires being used and the splitting of the signal should work in both cases. They may hang on an IDSN pbx from the third party though and that may complicate things. In any case you'd need physical access from those lines to your own POTS endpoint if they're not willing to help.

It also depends on what type of ISDN access they have, there are two. In the one case (pmp) they actually have their 'own' ISDN for want of a better word, in the other case they're most likely hanging off the third party's ISDN line (pmx).

Also the fact there are 4 wires coming into it doesn't necessarily mean there are two phone lines on this. ISDN doesn't need two lines to provide two numbers/channels. I'm not much of an analogue man but I have 4 wires coming into my house but I only got one POTS line.

You'd need someone to assess the situation on site. Too much information needed to give a conclusive answer here.

brianmc

Boskowski wrote: »

There may be contractual reasons but from a tech point of view you don't need to switch away from ISDN to get DSL. Its the same two copper wires being used and the splitting of the signal should work in both cases. They may hang on an IDSN pbx from the third party though and that may complicate things. You'd need physical access from those lines to your own POTS endpoint.

Also the fact there are 4 wires coming into it doesn't necessarily mean there are two phone lines on this. ISDN doesn't need two lines to provide two numbers/channels. I'm not much of an analogue man but I have 4 wires coming into my house but I only got one POTS line..

Hmmm... so the real nub of the question is what infrastructure that uplink is coming through...

Would it be an easy job for a technician to test that line at the ISDN box to establish what is feasible?

Dardania

Would it be simpler to change the ISDN to ADSL over a PSTN, and provide voice telephony over VoIP on the ADSL? No need to care about cores etc...

Of course, requires verification of whtether the ISDN is via the shared office spaces PBX or direct with eircom, per Boskowski's point...

Would also make it easier if the voice lines are on VoIP if they ever wish to move...

Blueface are good for VoIP

brianmc

Interesting suggestion!

Thanks for that. I'll check it out.

But yes, it still comes down to establishing what way the ISDN line feeds through to their office.

Cuddlesworth

There could well be very valid reasons why the host company don't want this to happen, especially if your network infrastructure is not isolated.

The last thing you need is a investigation into a DHCP conflict or broadcast storm, with the host company finding out that it was caused internally, with a new backdoor into their company that they expressly denied.

brianmc

Thanks Cuddlesworth. We're looking at all options. We won't be doing anything rash.

Boskowski

brianmc wrote: »

Hmmm... so the real nub of the question is what infrastructure that uplink is coming through...

Would it be an easy job for a technician to test that line at the ISDN box to establish what is feasible?

A telecoms technician would be able to assess the situation in full by looking at their endpoint and pbx.