"Peter R Cook" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> In message <(E-Mail Removed)>, Andrew Sayers
> <(E-Mail Removed)> writes
>>Hi
>>
>>I've just installed and setup my new ZyXEL 2602HW router. It's excellent.
>>I wanted
>>the VOIP that it supports, but I've yet to set that up.
>>
>>There is one very peculiar problem though. When I get an incoming call
>>over the
>>normal BT land line the Caller ID info has stopped showing up on one of my
>>phones.
>>
>>I've got a DECT phone setup with 4 handsets, and an ordinary wired phone.
>>They are
>>both plugged into the master socket via a splitter. The router is plugged
>>into a hard
>>wired extension run from the main socket, this extension was fitted by a
>>BT engineer
>>who was kind enough to fit it when he ran in the new line that replaced
>>the ISDN one.
>>This all happened a couple of years ago.
>>
>>Now, the phones all work, but caller ID only shows up on the DECT phones
>>not on the
>>wired phone. Initially I though that it must have gone wrong, but I needed
>>to turn
>>off the router last evening, and lo and behold caller ID started working
>>on that
>>phone again. Putting the router back on stops it working. It worked fine
>>with my old
>>router (a Linksys WAG54G), but seems to have problems with the new one. I
>>tried a new
>>filter on the phones too, just in case.
>>
>>Can anyone (Kraftee?) through any light on this? It's not the end of the
>>world, but
>>I'd be interested in getting to the bottom of it.
>>
>>TIA
>>
> Almost certainly this is a consequence of the effect the new router has on
> the frequency response of your line at caller ID frequencies.
>
> Caller ID (AFAIK) is transmitted as a 1200baud bitstream between rings.
UK caller display info is sent before the 1st burst of ringing
See
http://www.ainslie.org.uk/callerid/cli_faq.htm#Q_6
"British Telecom developed their own standard, which wakes up the display
with a line reversal, then sends the data as CCITT V23 modem tones in a
format similar to MDMF."