She'll not take any more, Captain !

Nice surprise this morning, ran the BTw speed tester and wondered why I had 74meg downstream profile, JDSU confirms sync (always a little lower than the modem manages) at 73468/20000,

Interesting also, as the tester had shown a max achievable rate of 77meg.

I have not asked for an upgrade, and the only other confirmed case of 80/20 I know, was contacted by BT retail telling him he was going on a trial....... nothing similar received here.

So it looks like that's it for my line, finally topped out at 74 meg. Not bad, starting back 12 odd years ago with 512Kbps and a USB modem.

Shame I haven't the equipment at this end to make the most of it..........



1. Best Effort Test: -provides background information.

Download Speed
24 Mbps

0 Mbps 72.93 Mbps
Max Achievable Speed

Download speedachieved during the test was - 24 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-72.93 Mbps .
Additional Information:
IP Profile for your line is - 72.93 Mbps

2. Upstream Test: -provides background information.

Upload Speed
13.88 Mbps

0 Kbps 20 Mbps
Max Achievable Speed

Upload speed achieved during the test was - 13.88Mbps
Additional Information:
Upstream Rate IP profile on your line is - 20 Mbps

...noticed also that the downstream sync profile is now lower than this morning, settlig down maybe.

Has anyone else had this unrequested hike ?

Edited by Zarjaz (Sun 08-Apr-12 20:34:47)

In reply to a post by Zarjaz:

So it looks like that's it for my line, finally topped out at 74 meg.

Vectoring might give you more

?? What's 'vectoring' ??

Short of recrimping every connection between here and the cab, and making sure the twist is tight in said joints, I suspect that's it, sync wise.

until they tweak the VDSL technology again.

www.alcatel-lucent.com/vdsl2-vectoring/
http://www.ospmag.com/issue/article/vdsl2-turning-co...

OK, I can see that there's a little room for occupying more bit's per bin up the top end, but ....

I had thought that when I did 40/10 then it would go higher, now I don't get the full 80, that must be it ??

Does vectoring require any hardware replacement? Or is it just a different code/method of sending the signal?

that's it with the current frequency profiles and technology, I agree. If vectoring allows noise cancellation to give you more effective SNR then the speed can go up.

Then you need a second line to double it with bonding

In reply to a post by Zarjaz:

So it looks like that's it for my line

When anyone says something like that I'm always reminded of the dial-up days, when ~50kbps was regarded as close to the maximum possible, with learned quotes about line bandwidth and Shannon's theorem to back them up.

Now I can download 200 times faster than that down the same bit of wire, and nearly 1,500 times with the aid of a bit of fibre

Does vectoring require any hardware replacement?

I wouldn't think so, from my (limited) understanding. Or maybe it requires an add-on unit to analyse the noise and introduce the anti-noise. Might be proprietary too, so if you backed the wrong vendor you don't get it, but hopefully it'll be standardised.

http://www.assia-inc.com/DSL-technology/DSL-knowledg...


From what i've been reading, a Line with vectoring Zarjaz will take your speed of 74 to well over 100

Edited by deleted (Sun 08-Apr-12 11:32:20)

In reply to a post by Moradin:

From what i've been reading, a Line with vectoring Zarjaz will take your speed of 74 to well over 100

As he will be .

Yes, I remember that. The 56K modems were supposed to be 'it' in terms of speed for the copper.

I was still happy of course with that as I am old and started running a bulletin board with 300 baud...

Steve

I started with 2400baud on Compuserve, but even with the aid of an off-line reader (TAPCIS, of blessed memory), the phone bill could be a wonder to behold... especially when I was a sysop on three forums

My pbone bills were high and then someone introduced me to this little circuit thing that you could put on your phone so that when some dialled you it was free. Something to do with old phones being AC and switching to DC when the receiver was picked up. The circuit 'picked up' the phone but the exchange thought it wasn't connected.

All highly illegal but I was only 14 I think at the time.

In reply to a post by boxst:

I was still happy of course with that as I am old and started running a bulletin board with 300 baud...

Steve

Yes, I started off with an old ex BT 300 baud modem. The computer I had at the time did not have a terminal program, so I wrote one complete with built in dialler. (I think the computer was possibly my old Video Genie).

In reply to a post by boxst:

My pbone bills were high and then someone introduced me to this little circuit thing that you could put on your phone so that when some dialled you it was free. Something to do with old phones being AC and switching to DC when the receiver was picked up. The circuit 'picked up' the phone but the exchange thought it wasn't connected.

All highly illegal but I was only 14 I think at the time.

I just had a company phone line installed. I used to dial-in to CIS on the New York node because they got 19k2 before the UK. Ironically the tables were turned later on as I think we got 36k before them.

In reply to a post by Zarjaz:

Short of recrimping every connection between here and the cab, and making sure the twist is tight in said joints, I suspect that's it, sync wise.

Some people take the dog for a walk on Sunday mornings.

Now who could this have been this morning, twisting & crimping & muttering "Where's my 80Mb?"

Guess who

Where did you get the photo ? Looks quite recent .......

Wait until they release the 35MHz profiles ... with those you will get your existing and then possibly a little more from the long tail ...

Google images.........under Z for Zarjaz

when ~50kbps was regarded as close to the maximum possible, with learned quotes about line bandwidth and Shannon's theorem to back them up

all of which were true for audio based data transmission

Sending RF down the phone wires changed the rules.

In reply to a post by yarwell:

Sending RF down the phone wires changed the rules.

Not really... there's no fundamental difference between RF and AF, they're just convenient human-oriented labels, the electrical equations are identical.

But I'll agree that techniques that can be used at RF may well not be practical at AF.

there's no fundamental difference between RF and AF

other than the frequency, of course. The previous "56k" limit was for use of audio band only with transmission over the phone voice system - it wasn't improved upon - not least because the digital exchange only had 64k fo bandwidth per circuit to carry the modem traffic to the ISP.

So I would argue the 56k limit was and is correct for its context. Putting new kit into exchanges and allowing the use of more frequencies changes the limits and the bandwidth that can be considered.

I worked on "RF" down at 10kHz and below. Data rates were a little low but ranges were quite impressive!

In reply to a post by TheHorseman:

In reply to a post by boxst:

I was still happy of course with that as I am old and started running a bulletin board with 300 baud...

Steve

Yes, I started off with an old ex BT 300 baud modem. The computer I had at the time did not have a terminal program, so I wrote one complete with built in dialler. (I think the computer was possibly my old Video Genie).

Woo, a modem I started with an acoustic coupler and buying access to the computer at Imperial College. Mind you it was 1976.

Teletype to an acoustic coupler somewhere between 1970 and 72. Writing a commercial program in Basic. In Manchester, talking to a bureau in London.

In reply to a post by simon194:

In reply to a post by TheHorseman:

In reply to a post by boxst:

I was still happy of course with that as I am old and started running a bulletin board with 300 baud...

Steve

Yes, I started off with an old ex BT 300 baud modem. The computer I had at the time did not have a terminal program, so I wrote one complete with built in dialler. (I think the computer was possibly my old Video Genie).

Woo, a modem I started with an acoustic coupler and buying access to the computer at Imperial College. Mind you it was 1976.

The ex BT modem I had was large, I think it was intended as a 19" rack mount job. It weighed a fair amount too. I had just encountered computers in '76 as that was when I started my second job (and I'm still there just over 36 years later).

I don't feel quite so old now