[clug] Re: MythTV on TransACT

[Rodney Peters]

On Wednesday 23 August 2006 21:07,  steve jenkin wrote:
>  Pardon my ignorance, but how is a VDSL modem different from a standard
>
> > ADSL modem.  Surely you're still just talking about a 8000/1000
> > connection to the CPE, which AFAIK is possible even with an old ADSL 1
> > modem.
> >
> >From Wikipedia:
>
> <http://en.wikipedia.org/wiki/VDSL>
> "300 meters(1kft), which allows for 26 Mbit/s symmetric access or up to
> 52Mb/s down / 12Mb/s up asymmetric access."
>
> Normally VDSL is quoted as '55Mbps'...
>
> They also have a nice ADSL article :-)
> <http://en.wikipedia.org/wiki/ADSL>
>
> I *think* that "xDSL" standards by definition are single pair, versus
> the two-pair (4-wire) of 10/100/1000-BaseT.  BTW: 100-BaseT on cat-5e
> cable will deliver 100Mpbs full-duplex over 300m or more... Which makes
> you wonder why Transact did what they did.
>
Just for the record, 1000-BaseT requires all four pairs.  To obtain a concise 
explanation of it google the HP site for;

copper_final.pdf

AFAIK, a 1000-BaseT device should auto-negotiate back to 100 or 10 bps if the 
link can't work at 1000.  However, I've heard of one situation with a 
TransACT phase 1 (VDSL) user upgrading to a new Mac (gigabit Ethernet ?) and 
no longer being able to connect to the Internet from their study, although it 
would work in their living room, when connected directly to the STB via a UTP 
fly-lead.

I suspect that the fixed UTP cable installed between their living room and 
study was either run in 2 pair cable or did not have all 4 pairs terminated.  
Said (individualitic) user insisted on doing their own testing (borrowing my 
cable tester for the purpose) and confirmed that not all 8 wires were  
working, but never gave me detailed feedback.

Could be an issue for other VDSL users.
     . 
> > Curious Paul.
>
> HTH
> stevej


Rod