> This isn't quite how it works.
>
> PSTN (analogue) calls cross the intelligent network as single B-channels
> (64Kbps). It makes no difference at all whose network it crosses, 64Kbps is
> 64Kbps, pretty much error free. (Incidentally, this is why V.34 is the end
> of the road for analogue modems. The Shannon liomit means that the
> underlying carrier must have at least twice the bandwidth of the signal
> being carried, thus for PSTN that limit is half of 64Kbps which is 32Kbps.
> Allowing for a few losses here and there, 28.8kbps is about the limit.)
I don't presume to know all that much about this subject. However, I do
believe that it makes a difference which carrier you use. If Optus is
using slower or more utilised switches, then the traffic across that
network is going to be slower, no? This will at least explain why the
time taken to create a connection (get the other end to start ringing)
takes longer. I'm not sure if this would affect the bandwidth available
for the connection (I happen to think not).
As for UTS, I wouldn't think their equipment has changed at all. In fact,
I'd be shocked to hear that their equipment has changed. The changes should
not affect UTS' PABX at all--if it did, how would they handle the changeover
period?
> The line that you are dialling in with is analogue only to the first
> optimux/exchange. It is generally safe to assume that it will have the same
> (analogue) characteristics from call to call, so if you are seeing different
> characteristics for two different paths into the same modem, the problem is
> almost certainly arising at the UTS end. Because 9514 is digitial all the
> way into UTS's premises (I believe) the problem (if indeed it exists) is
> actually with the equipment on UTS's premises. At a guess, this equipment
> belongs to UTS and is therefore the domain of ITD.
I agree, up until the UTS bits. The 330 should be digital all the way
into UTS. If it isn't, and the 9514 is, then surely that's a sad
indictment on the new service.
Peter
------------------------------------------------------------------------
Peter Meric pmeric@nospam.socs.uts.edu.au
pmeric@nospam.progsoc.uts.edu.au
pmeric@nospam.acs.itd.uts.edu.au
"Stupidity cannot be cured with money, or through education, or by
legislation. Stupidity is not a sin, the victim can't help being
stupid. But stupidity is the only universal capital crime; the sentence
is death, there is no appeal, and execution is carried out
automatically and without pity."
Robert Heinlein