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[Weaver]

The lightning isolation preferred solution now is to use a single pair of 100 Mbps fibre media converters back-to-back, on one side is a port for PPPoE on the router (a Firebrick) and on the other side is a VLAN switch (prob HP) to which all the modems are connected. This allows me to have more than three modems if I can get yet another line out of BT, solving the limitation of the number of free ports on the Firebrick (currently zero).

I can't remember where I found a good-looking fibre media converter. Damn, keep losing urls, will now have to do the research again. Will also have to find s pair of v short fibre links. The fibre media converters were £50 × 2, rather better than × 2 × 3 for the original solution without the switch.

[benji09]

  Weaver, If I hear on the weather forecast that a storm may be coming - even where I live, outside London - I put the radio on to listen to the clicks and bangs to warn me of problems to come. does give false positives, but allows me to play safe. In the case of bad storms coming it alows me to disconnect my Sky FTTC modem/router, and change wirelessly to my son's Virgin line, taking all my VOIP lines as well ! So in answer to your question I would definately, if I were you, listen to your long wave radio. Bear in mind that the Met Office does the same thing, but on much lower frequencies...........   

[Black Sheep]

Nice bit of info ^^^^ Cheers. 

[Weaver]

I watch the website lightningmaps.org when things are looking bad, which draws a map of lightning strikes every so many secs, and I have an iOS app called NetWeather or something like that which does pretty much the same thing, with updates every 15 mins or so for lightning strikes all over Europe.

Perhaps I need to buy a traditional style radio, and then I need a small child or a slave to monitor it, as I am asleep most of the day (suffering from CFS and little sleep at night some times because of pain). An app that could do push notifications would be very good, as the two services mentioned earlier don't alert you, you just have to keep peering at them.

[burakkucat]

On 21CN:
I think b*cat got the history (with voice and data) correct. For me, the distinguishing feature *now* is that 20CN was based on an ATM core, while 21CN is based on an IP core.

As BT have said they expect most subscribers to be using IP-based voice by 2025, the question is ... how? Do they intend to re-invoke the original 21CN picture, with voice converted at the MSAN (or, presumably, now including the DSLAM MSAN in the FTTC cabinet)? Or do they introduce voice gateways in the house, and convert it to IP before it ever leaves the home!

Those of us (vaguely) familiar with the telecommunications history of this nation will recall how ISDN was going to be the next big thing. One circuit to each end user, into which could be plugged a variety of devices. The circuit was to have been digital and existing analogue telephones would need to be connected via an adaptor (ADC & DAC, dependent upon the direction being considered). ISDN was to have been a small subset of a totally IDN . . . But then ATM and Broadband (using FDM) appeared. So now we have (essentially) analogue local loops -- i.e. all that is maintained by Openreach -- with the rest of the infrastructure completely digital. (Give or take an odd exception.)

My limited understanding of what was proposed for 21CN telephony was that the conversion to/from IP would have been performed at the end-users premises. I.e. there would have been some form of active NTE/NTU into which the classical analogue telephone could be connected.

[burakkucat]

On optical isolation:
Would it be enough to just use some media converters for the ethernet connection (on the PPPoE leg)? Something that did 100base-tx to 100base-fx, leaving a short fibre leg?
http://www.cclonline.com/product/85222/INSIXTMC100SC/Wired-Accessories/Dynamode-Insixt-INSIXTMC100SC-100TX-100FX-SC-Multimode-Media-Converter/NET0664/

At £7-66 (inc VAT) each it's almost worthwhile buying a pair, with which to play! 

Obviously a length of glass (or plastic) fibre, with appropriate connectors, would also need to be sourced. 

I have a vision of Ian setting up such a link between his shed and the house. 

[burakkucat]

Perhaps a pair of ex-BT NTE2D's could be used, back to back?

Having one in my grotto, I have previously given it an examination. Two fibre links (glass or plastic) would be required as there are separate "Go" and "Return" paths. The "Go" of Unit 1 connected to the "Return" of Unit 2, etc.

[benji09]

  Incidentally, if a line that is disconnected at both ends, or tv aerial that has been unplugged, can pick up a charge during stormy conditions that can wreck your equipment when plugged back in afterwards. One of my work mates years ago was working on an  an aerial distibution system in the sub basement of our building, realised the the coax cable from the roof had not been grounded. He found this fact out only when tried to weld his pliers to the rack and the cable braid of the coax. He was so surprised that he fell of his elephant box  onto the floor.....................