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Re: 28.8k transfer speed



Hi!

In spite of all the important details that Amit taught us, Yuval is
correct in this point. Bezeq (sometimes) installs lines of 1+1.
I ordered a new line (just a few days ago) and they could not
promise me that it would not be a 1+1. Even if you will specify
it in their form and indicate that this line is dedicated to
Fax/Modem, they may still install a 1+1. The previous time I
ordered a line, I asked (in the form) that it will not be a 1+1,
I specified it again near the sign (and I wrote that it is a term
for my order!), I put "x" on the box of "Fax/Modem", and still they
were going to install 1+1 (fortunately I was in my home and didn't
let them to install it...)

It is very easy to know it is 1+1: 1+1 requires a special small box
to be installed in the 2 phones which are connected to the same line.
You must be in the area when they come, in order to check that
everything is OK (BTW: I heard about problems in Bar-Ilan after a
simple installation of Nezeq: they installed a simple line, but
disconnected a neighbor cable in order to complete the installation
easily. This cable was an Ethernet cable which connected a server
computer to a LAN. After moving the table again and again, a hard
disk of a neighbor computer was damaged and crashed. So take a look
at them, even if you don't need a not 1+1 line!)

Eli Marmor

amitm@doronx.iso.dec.com wrote:
> 
> > > Hello,
> > >
> > >   I hardly get 3kb/sec ever, even when transferring to/from the local
> > >  machine (the ISP machine).
> > >   What could be the reason for such a difference?
> >
> > You should check whether the line you're using is not 1+1. Bezeq sometimes
> > shares lines between two users. Since the maximum capacity of a line is
> > round 33kBaud, if you split it to 2 it can limit you to 'bout 14.4 speeds.
> > Note that Bezeq doesn't promise they won't change your line status (unless
> > you order a special more expensive line).
> >
> >          Yuval El-Hanany
> >          yuvalle@math.tau.ac.il
> >          yuval@checkpoint.com>
> 
> Sorry Yuval, but this is really wrong. If the line is connected to a digital
> switch (and MOST are by now), then the line should hold exactly 4KHz of
> bandwidth from the home to the switch. Between the switches - you need not
> worry. Bezeq's infrastructure uses really high capacity lines between the
> switches. So 4KHz should enable 28.8Kbps!
> 
> The only possible reason is either -
> 1. He is connected *through* a bad switch (somewhere between him and the ISP),
> 2. Or he may be directly connected to one of the few old analog switches.
> 
> About shared lines -
> All digital lines are PCM coded as a standard. The standard promises you the
> 4KHz bandwidth. Even ADPCM compressed lines (which aren't in use in Israel
> because of the relatively low demand on the lines) still allow 19.2Kbps, and
> a lot of people in the USA could testify to that. I used to read the Usenet
> group comp.dcom.modems around when the V.FC and V.34 standards started. Most
> have managed 21000bps (V.FC) and some 24000, 26400 etc.
> 
> What I said by "the relatively low demand on the lines":
> I mean that in Israel, the load on the lines between the switches never get
> high enough (as they do in the USA) to necessitate ADPCM or better compression
> methods.
> 
> The only "More Expensive" lines that you can order are ISDN lines, but almost
> nobody has them yet, nor does anyone have the expensive modems to use them.
> 
> Hope this clarifies a few things.
> 
>                 Amit.