Euro Electrics

[Mike]

For new builds yes. But might be expensive to retrofit to some properties.

[Andy Hall]

I wasn't talking specifically about BT or necessarily about the UK.

[Mike]

Not completely. The bandwidth used was set up and torn down using the ATM signalling protocols. Of course with IP these links may stay up for long periods of time but the billing of those links to the user (e.g. your ISP) often uses that information unless they take the full capacity 100% of the time.

I'd bet on that going first.

Requirements change and things evolve. Fifteen years ago everybody expected the bulk of data on the network to be private business data and video. It is but both now are packetised. But what ATM does to is allow dynamic allocation of bandwidth between users of the same resource (the links) to a far higher degree of control than alternatives so I expect this will continue for some time. Also currently BT provides most of the routers for broadband and ISPs lease this service with only agregated traffic back-hauled to them. But in fact the network was designed such that ISPs could tunnel all the way through to each DSLAM using ATM, hence allowing them to offer services using their own servers and routers without co-location. To date I believe only the VoD people have utilised this as they have such large bandwidth requirements but I think this may change as we begin to use ever increasing amounts of data for our £15/month.

I did use some of the Virata ATM25 PC cards myself back in 1996 when Ethernet still did occasionally drop packets and have large variable latency, making it virtually unusable for voice and real time video. Once this situation improved this was never going to happen.

[Andy Hall]

I think that diversity makes life interesting.

Not an issue. I have a universal adaptor made by Fujifilm and very good it is too. It will take any plug type into the top and plug into any wall outlet, plus it has a 5A fuse.

Every hotel that I have been to for at least 5 years has some means of connecting an RJ-11. Nowadays, in most places that I stay now they have WLAN, although are still gouging customers for it rather than making it reasonably priced or free.

I don't think that I would regard the Euro as an example of positive harmonisation. I suspect that it will have a rough ride in the short to medium term as people realise that it's all about politics and little about economics. While it's convenient to only carry around about 5 currencies rather than the 10 or so that I used to carry, I am less and less convinced of the point of having harmonised currency.

[Mike]

They didn't. But the core of the network is large ATM switches connected over the SDH network.

[Mike]

Which rules out Europe as they all follow BT :-)

Assuming you therefore mean the US, they never made the big move to ATM as much as Europe, they still don't have a single clocking system, and also have so many bypass providers the existing network is such a mess that any technique for getting a link to work reliably it is welcomed. IP transport fits the bill perfectly from a user's standpoint.

[Stefek Zaba]

That's about it. Paul Cook's Commentary speaketh thus: 20 yrs at 70 degrees, halve the life for each 8 degree rise. Wanna general formula? The man says,

ln t = 15028/T - 31.6

where the magic numbers are specific to PVC, t is lifetime in hours, and T is absolute tem (in K).

p.108/section 6.1.3, since you ask ;-)

Stefek

[Mike]

Yep. My Stayer angle grinder blew it's fuse last Wednesday. The one before was a DeWalt 566 drill around start of May. April had nothing but March had fuse on a 110v transformer driving a hired Makita core drill and one on a B&Q PPPro mitre saw go. This is for diy work, albeit quite a lot of it as I've semi-retired now and am having fun.

Our supply is at 249v and is second on a long line feeding six farms so I've always assumed it was due to spikes on this.

[Andy Hall]

They are almost always set up with PVCs.

The operators did.

That depends very much on operator. There are at least four different ways of achieving QoS with IP including simply throwing enough bandwidth at the issue so that it goes away. Many core networks are implemented in this way

That applies to ADSL to some extent, and you are describing BT Wholesale's structure. I think that LLU will become increasingly important, but again I was not specifically thinking about BT or the UK.

Latency is relevant only for video conferencing. For streaming, sufficient use of buffering or throwing more horsepower at the problem largely makes it go away anyway.

[Andy Hall]

All set up with PVCs connecting IP routers together....

[Andy Hall]

I've never thought of Europe as "somewhere else" so don't think in terms of "they" either. It certainly is not the case that operators around Europe, even some of the large old telcos are following what BT is doing. Many that I talk to are able to leapfrog where these guys are simply because they don't have the old legacy technologies such as frame relay and ATM.

No I don't mean the U.S. at all.

That appears to be true worldwide.

[Andrew Gabriel]

The phone calls run directly over the SDH though. The trunk switches are basically add/drop SDH MUXs for inserting and extracting 64kbit channels from the stream of SDH fames passing through. There was no ATM involved in the PSTN (at least back when I was working on it).

ATM is used to provide the broadband infrastructure, but that's quite separate. They probably route it over the SDH network just as they route all leased lines over the SDH network between the endpoint exchanges.

[Mike]

They used to say "shake a tree in Silicon Valley and a VC falls out." Last time I was there the place was half empty and there was certainly far far less in the way of recent startups. They are happening, as they are in Europe, but I think it's more conservative there as well now.

Agree - but my original point was that VCs demand startups to have standards in place before full funding is given. Of course if their application area doesn't need standards or there are existing standards then this isn't an issue.

Agree again - but although there still probably is lots of dicking going on in places (IEC was mentioned by one person - don't know if it's true - not my area) many bodies are getting their act together rather well and one sees better proposals, more agreement beforehand and far less of the arguing about the use of a specific word or phrase when it is obvious what is meant than one used to. Of course one still gets opposing camps but at least they both arrive with half the room supporting each of them and both with well written proposed standard documents that are well researched and actually work.

Also as investment in comms and semis have shrunk, possibly the main outlet for technology VC money is biotech where the returns are often 12 years away or more which to my mind makes waiting for standards seem quite quick.

[Mike]

I've got the same one. It's very good. But it wouldn't be needed if we all used the same plug.

But only half of them seem to work as they are still connected to non-harmonised local loop equipment.

They still also have a lot to learn on provision Only place I could get it a reliable connection on my last trip was on the terrace outside the lifts. Some people claimed they could get access in their rooms but many other couldn't.

Dollar, Euro and Yen. What else do you need ? Almost everywhere else prefers you to use dollars rather than local currency :-)

The Euro will have a rough ride. But currently the dollar is. In the Lawson era the pound was. And the Yen was on the verge of collapse not that long ago. Currency fluctuations happen. But if the whole of Europe goes up and down together it makes it a lot easier.

[Mike]

Let me guess - you work for Cisco ?

[Mike]

Sorry yes. Didn't mean to imply it didn't. But PSTN is a smaller percentage of the network now with the links for mobile baststations often aggregated onto ATM VCs. This and the growing use of voice on private networks means that a lot of voice does get carried over ATM now.

[John Rumm]

I can see that it might be irritating, but that is about it. It is easy enough to overcome and does not seem like a justification for member countries spending billions on change almost for the sake of it.

I also expect the problem will solve itself more with time. I have noted a trend in small devices more frequently using SMPSUs in place of conventional linear supply wall warts. Since these are far more input voltage flexible, and the PSUs can be that much smaller, you open the possibility of shipping one PSU everywhere, more often internal to the unit (with a IEC or Telefunken input socket), and just needing to package the right mains lead. Even if you got a delivery with the wrong one it would not be a major problem to sort at a cost of pennies per unit.

I would agree with Andy there...

First country to bail out of the Euro? Ireland or Germany I wonder?

Visa, Mastercard ;-)

[John Rumm]

You pre-empted my next question ;-)

Like you I have been doing pretty intensive DIY over the last year (loft conversion and stuff) and have yet to lose a fuse. Our voltage is a reasonably reliable 240 though. I have measured our supply impedance at about 0.35 ohm, so it is also reasonably "stiff", although you obviously can pull it down a bit under high load.

Have you considered some spike suppression (on your favourite extension lead for example) to see if it changes the situation?

[John Rumm]

I am sure the concept could be adapted to an electric central heating boiler though... that might make it more manageable.

[asn1]

ASN.1 is well alive and the standardization around it is progressing. Visit the ASN.1 Information Site at

for more information about application domains and what's going on as far as its standardization.

O. Dubuisson