Landline conversion to digital

FAXed documents have proof of delivery, and more secure? than IP. The NHS have medical confidentiality to worry about. Not all electronic documents can travel via the NHS intranet.

Not really. A fax machine will confirm that the other end received something. I have received blank sheets of paper where the sender put the document into the fax machine back to front. I have also received illegible faxes where the paper feed at one end or the other was unreliable. I have received faxes so corrupted by line noise that they had large chunks missing. I have received faxes where the sending machine concatenated multiple pages into one logical page which then exceeded the page length limit for the receiving end causing truncation. Sometimes the paper ends up on the floor behind the table. As for security - there is none. Transmissions are not encrypted. Anyone can walk up while a document is being printed and read it. The data can easily be intercepted by those who control the telephone system. (Such facilities are mandatory in many countries.) Good riddance! John

What diameter is the fibre 'dropwire' ?

Some of us did useful work with <cough> 56K dialup :-)

Try firefox's responsive mode to see how useless most of today's web is at GPRS speeds on an 800x600 monitor ...

its actually thinner than the BT drop wire... :-)

about 4.5mm

Mine is an asymmetric figure 8 layout. The larger section containing the fibre, layers of bedding and a fairly tough outer is about 5mm diameter.

The smaller adjoined section is perhaps 2 to 3mm, and contains the copper pair. The installers peeled off the copper pair about 1.5m back from the ONT, so the more fiddly bit of wiring could be done without it. They just coiled up the copper pair and left it dangling.

Once the analogue part of the service is turned off, there will be no line power, ring tone, or anything else on that copper pair other than the VDSL signal for the broadband.

That should save a power station or two! :-)

Oh wait, they'll be used for electric cars and heat pumps instead!

I think that's a transitional install - ie they still provided a copper pair for voice? AIUI the long term plan is to turn off the copper, so they would only be installing fibre once people's landlines became VOIP. Which is why OR is keen to get people moved ASAP.

(My previous abode with FTTP had the old copper line still in place, which came in off the pole to the loft, while the fibre came in from the same pole by running down the house and entering at ground level.)

Theo

Probably a case of having a clear marketing message... so not promoting the lower speed offerings at all to avoid confusing with the FTTC/SOGEA products, means that 160 Mbps is a good "entry level" FTTP product since it offers a noticeable "upgrade" over 80 Mbps FTTC.

They used to then promote 350 as the next step, but since openreach now charge the same for that as 550, there is no point in not selling the faster option (hence my "free" upgrade).

Looking at the openreach price list it seems to suggest they only offer

Also PON can't realistically support symmetric rates due to the TDMA nature of the uplink.

In fact, since the concept of timeslot only applies to the upstream, not the downstream, and they sell 10/20/30/50/75/115 Mbps upstream speeds, so maybe the actual slot is 5Mbps worth? But they only "sell" in

As a matter of interest, does the copper play any part in strengthening the cable in long runs between poles? If they didn't have the copper, would they have to put some other kind of metal core inside to support it?

Nick

the BT drop wires have steel "strength members" as well as the copper, the even older ones were just copper clad steel wires.

These upstream/downstream ratios are all calculated from years of ISP data to reflect pretty much the normal consumer 'pattern' I am not sure how they reflect into the timeslots at all. Its quite hard to find out this stuff.

Copper is a very ductile metal. So when placed under tensile load, it will elongate permanently.

The rate of elongation will depend upon the tensile load placed upon it. If however its taken to extremes, you will then get tensile fracture.

I seem to recall on telephone drop wires, there is an outer jacket made of an engineering polymer like nylon and there was also a steel catenary wire embedded within to improve the cab;e's tensile strength?

Oh yes, CCA or CCS.... the poor man#s electrical wire.

CCS = Copper clad steel (very prone to aqueous and galvanic corrosion)

CCA = Copper clad aluminium (very prone to stress corrosion cracking fracture as well as aqueous and galvanic corrosion)