On 16/11/2010 16:39, Herbert Graf wrote:
> On Tue, 2010-11-16 at 02:29 +0000, Michael Watterson wrote:
>> 28K is Trellis encoded. 33k is using compression, it's really only 28k,
>> that's actually the highest speed analogue modem for end to end PSTN.
> I'm not sure where you get that.
>
> 28.8k is 3200baud, while 33.6k is 3429 baud, there is no "compression"
> involved to get 33.6k.
>
> The max theoretical bandwidth from analog end to analog end is about
> 35kbit/s.
>
It's a long while since I had one (28k/33k) Modem. I don't think=20
Wikipedia existed then. Maybe I presumed the 33k mode was compression as=20
I never saw that speed!

I gave away my 56K modem last year. . It spent a lot of time only doing=20
19K :(  Though when I had a Wireless Phone for a while it did 49k. Then=20
the Wireless company went bust and I had to go back to copper pair. Not=20
used it since Nov 2005 for Internet when I got in a 10.6GHz DOCSIS over=20
Microwave link. Cheaper than phone line and gives 8M down/1M up + 2 x=20
real phone numbers using QOS VLAN to the ISPs own PSTN gateway. The QOS=20
and codec is good enough that my Fax works on it.



> The fact that one end is digital (i.e. an ISP) allows for V.90 and V.92
> which are capable of 56/33.6 and 56/48 respectively.
>
That bit I'm clear on.
> https://secure.wikimedia.org/wikipedia/en/wiki/Modem
>
> TTYL
>

--=20
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