ADSL + Dial-up

Like many of us, I have an ADSL modem/router running 24/7.

Daughter-in-Law-to-be has just started a new job, and her company
requires her to connect company-provided laptop to a dial-in modem
on an 0800 number (at head office). Every time she attempts to
connect, she knocks the ADSL off line, but cannot connect to head
office.

The first time this happened, the ADSL stayed connected, but it
appears the remote end was disconnected and it took something like
2 hours or so and several reboots of the ADSL modem before the
system reconnected.

The second time, when we only tried once to dial-up, it required
just a reboot of the ADSL modem to reconnect.

Has anybody else experienced this. The equipment is a BT ADSL
modem and an internal software modem in her Tosh laptop.

When time permits, I will try the modem in my Dell laptop to
see if that has the same effect.

Geoff

Have you tried dial up with the ADSL modem disconnected from the line, and is the dial up modem connected via a filter?
What ADSL modem is it?

Running a dial-up modem over an ADSL-enabled line should be fine provided the dial-up modem is connected via a microfilter in the same way as any other phone equipment. I still have my old Courier modem setup for the (now very) rare occasion I need to dial into the network at my work (normally only if the VPN dies for some reason). My ISP also provides dial-up access in the event that the ADSL connection fails.

Would be useful to know if you're using the modem with a filter, also what BT ADSL router you have.

The ADSL modem is a BTVoyager2100-D6 which in itself is pretty reliable. There is a filter splitting the line 1) to the ADSL modem and 2) the other side to everything else. This is fitted at the master socket.

It hadn't occurred to me that I have no problem with the two sky box modems connected to the same line.

Asking in another place has brought the suggestion that the designed(?) to a price, not a spec., software modem in the laptop may well be producing excess levels of out-of-band noise and this is shutting the ADSL system down.

Thanks

Geoff

In reply to:

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Asking in another place has brought the suggestion that the designed(?) to a price, not a spec., software modem in the laptop may well be producing excess levels of out-of-band noise and this is shutting the ADSL system down.

---

If it is, then that inidcates that the filter is faulty since it is out-of-band noise which should be filtered.

The filter is required to stop all frequencies above the normal range for voice telephone which goes up to 3.4kHz. The ADSL range starts at about 25kHz. The modem may well produce higher frequencies than 3.4kHz, even into the ADSL range, but they are not needed and should be blocked by the filter.

I am astonished that a company should require an employee to use a dial-up connection when they have ADSL. Setting up a VPN through the Internet is almost trivial, cheaper and quicker than an acoustic dial-up.

I would suggest she ask if they can set that up for her and if not suggest further that, as they require her to take over your telephone, potentially for long periods, they should provide her with a dedicated phone line at their expense solely for this purpose.

All equipment other than the ADSL modem itself should be filtered, including Sky boxes. Just because these devices are not knocking the connection out, it doesn't mean that they are not reducing the data rate of the line. One day a BT engineer accidentally plugged a phone into my ADSL line without a microfilter, and it caused havoc with my noise margins.

Edited by deleted (Sat 14-Oct-06 10:31:16)

I use dial-up with my ADSL broadband connection working at the same time, it is a very efficient way of sending and receiving information. I would not be without my dial-up. Fit a different type of microfilters. I use ADSL Nation XF-1e Professional ADSL2/2+ Microfilters for top quality, the very cheap microfilters can let you down. (read the reviews)

Lowest price I have seen. http://broadbandzone.co.uk/shop/Microfilters_x40Splittersx412007.htm

Tiscali pay-as-you-go dial-up connection
Downstream actual speed 48Kbps
56K V.92 Zoom 3025-72-00C Hardware Fax Modem Internal (PCI)
-------------------------

Well, commercially available ADSL filters are only capable of a finite level of attenuation of out-of-band frequencies, and if the Tosh modem is putting out a high level of hash, no simple filter will prevent it getting to the other(ADSL) port and thus 'blocking' the ADSL receive path.

I removed all the devices on the phone network, except the Tosh laptop which was connected directly to the filter (via a 3 metre lead) and the the BT Voyager 2100 ADSL modem and the Tosh still knocked the ADSL off line. BTW the filter is a Puckah BT device.

Further investigation proved that my Dell laptop internal worked OK, and so did my external Courier modem, once I found something with a serial port!

Apparently her company will supply a second phone line under certain circumstances, although we have rigged her laptop to talk to her mobile via IRDa.

TTFN

Geoff

All the devices are fed via a filter.

Sounds more like RFI, is the offending laptop plugged into the mains when testing ? Try it without.