DSL compatibility...

Modem compatibility and configuration issues.
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Kevin Shields

DSL compatibility...

Post by Kevin Shields »

I have read all of the docs, I see the FAQ about caller id not working with DSL modems.

I have a phone that has caller id support built in, I see that the info is getting to that phone.

Yet I am not getting it via my modem. I have done all the troubleshooting in the help docs.

Note that my caller id modem is NOT behind my DSL modem. I have tried connecting directly to the phone line and connecting with a DSL filter - both don't work.

The FAQ says caller ID will not work with DSL *modem* - does this mean it doesn't work with DSL *at all* or that it won't work *behind* the modem?

Bottom line: I have DSL at my home on my normal phone line. I have a caller ID handset that works fine with caller ID. I am unable to get a POT modem to work with my computer and Acendis Caller ID (all I see are "rings" without any info) - is this expected?

Thanks,
kevin
Guest

Post by Guest »

Sorry, let me clarify. The FAQ says the following:

Q: Will Caller ID work with my DSL modem?
A: No. DSL modems do not provide caller information since DSL lines don't accept incoming calls.


This Q&A doesn't seem to really answer my question, though I am asking about DSL compatibility

At my home I have DSL. DSL is provided on the same line as my regular phone service (so I DO receive calls on that line no problem). To use a phone on that line I have to install a DSL between the line and each of my phones. The DSL modem is the only thing connected directly to the line without a filter.

I have been assuming that since my vtech phone shows caller ID that I would be able to also get caller ID via my computer modem (which does, definitely, support caller ID). However I have uterly failed to get caller ID via the computer modem. I DO see the "RING"s and I am able to successfully send AT+VCID=1 to the modem - but still I get no info.

As I said above I have very carefully walked through the troubleshooting provided in the Ascendis Caller ID help file. Checked the driver, used Hyperterminal as instructed, etc.

I'm half expecting you to tell me that with DSL I can't get caller id on my computer modem. If that is the case why does my vtech handset report it just fine?

Thanks,
kevin
Bill Root
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Location: Perrysburg, OH
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Re: DSL compatibility...

Post by Bill Root »

Hi Kevin,

As you deduced, the fact that you can receive caller id on your VTech phone shows that the phone line has the caller id signals. This means that your (analog) modem and Ascendis Caller ID should work. Modems (for analog phone lines), however, are usually pickier about the signals and oftentimes don't get or report caller id when a phone or caller id box on the same line will. Also, the newsgroups contain many discussions of DSL users with problems getting caller id working on modems and other caller id hardware, like phones and caller id boxes. DSL microfilters are apparently not all created equal, and some reportedly work better than others. If you're in the UK, these sites sell different microfilters that may work better:
http://www.adslnation.com/support/filters.php
http://www.solwise.co.uk/adsl_splitters.htm

Based on your descriptions I doubt you have extra filters installed (i.e., two filters between a phone device and the phone line, or a filter with no device connected), but if you do, remove them.

I suggest you first try disconnecting your analog modem from the phone line and plugging your VTech caller-id phone in it's place. Use the DSL microfilter that is currently plugged into your modem. If your phone consistently still displays caller id for incoming calls, then proceed to the next step. Otherwise, troubleshoot until you get this working. (You can use the same steps described in the next paragraph.)

Once the phone's caller id is working on the wire reserved for the modem, disconnect the phone and plug the modem back in. Use HyperTerminal to enable caller id on the modem. Now disconnect one device (other than the modem) from the phone line and test. Include the DSL microfilters as devices in this context. For example, you might first disconnect a fax machine from the phone line and then test. Then disconnect the DSL microfilter used for the fax (leaving the fax disconnected) and test again. If the modem still doesn't get caller id, disconnect another device leaving the previous device disconnected. Be sure to disconnect the DSL modem at some point, if the test keeps failing. If every phone device in your home is disconnected (including set-top boxes, digital video recorders, caller id boxes, alarms, etc) and the modem still isn't reporting caller id, try each DSL microfilter (one at a time) between the phone line and the modem. If your modem doesn't work with all other devices unplugged, try replacing the phone line running from the wall jack to the modem. If that doesn't work, try plugging the modem into another jack. If that doesn't work, check the wall jacks for poor connections. You claimed that the modem supports caller id, but at some point you may have to test it in a known working environment to avoid wasting too much time on a fluke -- maybe you're testing the wrong modem, or maybe the modem's caller id function died.

If the modem worked during troubleshooting, then you can try reconnecting all other devices. If the modem still works, then consider replacing the nonworking device, living without it, or trying another modem. It may be that any n devices will work but n+1 devices will not. Each device puts a load on the phone line, diminishing the signal. The filters also diminish the signal, probably to varying degrees depending on the model of the filter and individual variances.

If the modem doesn't work through all the tests, then I recommend trying other modems. Maybe you can borrow one from a friend, or buy one from a store that will let you return it if it doesn't work for you.

The troubleshooting steps may not be in the most expedient order for your situation -- adapt as necessary -- but remember that successfully troubleshooting stubborn problems means eliminating all possibilities by testing, instead of skipping tests that seem "obviously" irrelevant.

If you can post your results, successful or not, it will probably help other people dealing with DSL issues. Also, if anything is unclear or other questions arise, please ask.

Finest regards,
Bill Root
Ascendis Software
JCDEAN

I have a similar issue

Post by JCDEAN »

I have 2 phone lines. Both with Caller ID all phones show Caller ID tags being recieved on both lines. With the modem the first line the software works fine the second line does not work. It senses the ringing and says "no Information'.

The second line is the one with DSL. I suppose troubleshooting the filters is the next obvious choice on my end as well. I am going to remove all the DSL equipment to see if that makes a difference as well

The only other thing I can think of is that the line with DSL has different load and termination characteristics which I am sure is totaly possibile.

I'll let you know.

JC
Bill Root
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Posts: 1009
Joined: Mon Jan 19, 2004 1:29 pm
Location: Perrysburg, OH
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Re: I have a similar issue

Post by Bill Root »

Hello JCDEAN,

If you're saying that you're switching the same modem between the two phone lines and getting different results then the phone lines (that is, the signals on the phone line) must be different. Modems are usually pickier than caller id phones or boxes when it comes to caller id signals.

The filters sound like a good place to start, although I think filters are required for non-DSL devices. Some have suggested that cheap filters can cause problems. An aftermarket filter or a different filter may improve things. I'm assuming you have a filter on the DSL line going into the modem?

A different modem may also work better on the DSL line. Unfortunately we don't have DSL here so I can't comment on DSL and modem compatibility.

Finest regards,
Bill Root
Ascendis Software
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