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Re: tlug: Linux telecom nexus




-----Original Message-----
From: J. David Beutel <jdb@example.com>


>Hi y'all!  I'm here to stay, and the ISDN line comes
Wednesday.

Great!  Well, I can't answer everything on your list, but
I'll tackle some of it.

> 2. I need bilingual audio.  (second audio program?)  Can
the VCRs
>    here do that?  (to their audio line out?)  Or, do I
need to
>    get a board that can do it?

Bilingual VCRs are common of course, and if I'm not
mistaken, it's just a stereo VCR (English goes on one
channel, Japanese on the other) that they charge you more
for than if they just called it a stereo VCR :-)  I'm not an
audio-video nut, so there may well be ones out there that I
don't know about, but I've never seen one that let you
select left channel only or right channel only on the audio
line outs, but there is a cheap way to fake the effect: just
unplug the channel you don't want :-)

> 2. Is there a better way?  E.g., using a sound card?
>    Or, using ISDN somehow?  (E.g., many TA modems use the
>    AT command set.  Do any emulate voice modem
capabilities?)

ISDN TAs do not support voice.  As far as voice modems go,
Zyxel modems are very good, Sportsters aren't so great.
External modems are always better than internals.  I would
never have an internal again.  I don't know if Microcom
makes a voice modem or not, but if they do, I would
recommend it.  The Microcom Deskport series of modems are
very good.  They run cool, are compact, and are extremely
reliable.  We have thousands of them, and they almost never
fail and need to be power cycled.  I don't know if they are
available in an internal model or not, but these comments
apply to the external model.  As above, I would not
recommend an internal modem.  Externals are much more
reliable and give you the benefit of front panel LEDs for
diagnostics.

For an ISDN TA, I specifically recommend NEC and would also
recommend avoiding anything else.  If it's an Aiwa, you'll
need to patch the Linux kernel as a workaround for broken
firmware in the TA (Scott Stone can tell you what needs to
be done, since he got an Aiwa instead of buying an NEC like
I said :-)   ).

> Buy an external ISDN TA with a serial port and 2 analog
lines.
> Use my Linux box as a router.  Buy a board of some kind to
> connect my laptop (will decide later), since both serial
ports
> and the parallel port of the box will be occupied.

Ethernet would be the easiest way to connect your laptop, I
think.  A card in the desktop machine and an Ethernet PC
card for your notebook, and you're all set.

> 1. Where will the PPP daemon run, on the TA or Linux?
Both?
>    I.e., how does the TA do MultiPPP, BOD, etc?  Does
Linux?

It will run on Linux.  The TA is just a dumb box.  Smarter
than a modem, but still a dumb box :-)  Linux does support
Multipoint PPP, but you don't want to know how much that
will cost you to get in Japan.  Most ISPs don't even offer
it, and the ones that do will charge you at least double
their normal dial-up rate, as opposed to 64K ISDN, which can
usually be had for no extra charge over their modem
connection rate.

> 2. I think I understand dialing out, but how can I dial-in
to
>    my box at home via a digital channel?  (E.g., see the
Mobile
>    Phase below.)  Do I need to rent a second phone number
from
>    NTT?

Yes, you should get what they call a Dial-in Number, which
is a second phone number that operates on your ISDN line.  I
think the price was 900 yen per month or so.  Quite
reasonable, I think.

> 3. How can I get, or do, a permanent IP address from
Internet,
>    without a leased line?  I.e., I would like to be able
to
>    connect from anywhere on the Internet to my box at any
time.
>    Is there an ISP here which will dial-up my box when
someone
>    sends it a packet?

The answer is that you probably can't.  No ISP will dial
your machine when a packet arrives for it.  That would be a
real billing hassle to charge you for the phone call, etc.,
and would also take a special configuration just to make it
doable.  If you could find an ISP that would do it, you'd
probably find they would charge you more than they would for
a leased line.  You will really need either a leased line or
a low-speed connection such as 28.8 UUCP.  Not many ISPs
will do UUCP either, but there are a few.  I don't know what
the pricing is like, though.

> 5. How shall I connect my laptop?  I could add another
serial
>    port to my box, and run PPP over it, but the box might
be
>    getting pretty busy at this point.  Or, I could get a
10bT
>    LAN board, but would I also need to get a hub in order
to

As above, Ethernet.  I don't think you need a hub to just
plug two machines together, but small SOHO four port hubs
are available at low prices if you ever want/need one.
Another benefit to Ethernet is that if you get a third
computer that you want to add to your network (and let's
face it - Linux fans collect computers :-)   ), all you need
to do is plug all three into a hub and you're set.  Any
other solution doesn't give you this flexibility and
reliability.

> 6. If I buy the DSU separate from the TA, are all DSUs the
same?
>    Or, should I concern myself with DSU features as well?

Don't get a TA without a DSU.  You will not save any money
this way at all.  Most of the cost of the unit is the DSU,
not the TA, and buying them separately will get you no
advantages over an all-on-one unit and will probably wind up
costing you more.

>Mobile Phone/PDA Phase:
>
>  plan:
> Buy an ISDN TA that can do PHS and PIAFS too.  Buy a
mobile PHS
> PDA that also works as a phone (all in one).

There are two PHS communications standards.  One is PIAFS,
the other is Alpha Data 32.  The Alpha Data 32 camp is led
by DDI.  Alpha Data32 is ISDN compatible and any TA can do
an Alpha Data32 connection.  PIAFS is not, so for that you
have to buy one that is PIAFS-capable.  This used to cost
much more than non-PIAFS equipment, but I think there is now
little or no price difference.  But shop around and check.

> 1. Use it as a cordless phone at home, and also for
syncing
>    the PDA part to my Linux box.

You can do the cordless thing.  For syncing the PDA, it's
probably better to just plug it into the Linux box.
Otherwise, you're making a phone call to do it, and
enriching NTT while impoverishing yourself :-)

> 2. Use it mobile to my ISP for reading email (preferably
via
>    IMAP).  (Or, read email from my box, if I can get a
>    permanent IP address.)

Not many ISPs support IMAP (I don't personally know any that
do). You'll have to shop around for this.

> 1. How does the PHS sound quality compare to a cordless
phone
>    when using the PHS locally (like a cordless phone)?

I would expect it to be superior, insofar as the normal
sound quality in PHS mode is certainly better than a normal
cordless phone.

> 2. Can I have one phone number ring both my PHS and
>    analog (voicemail/fax) line?  I.e., can I give people
>    only one phone number?

No.  The PHS number is the PHS number, and has nothing to do
with your NTT phone line.  I don't think you will be able to
get PHS calls when it's in cordless mode, either (can
someone who runs their PHS cordless confirm this?).

> 3. Would the PHS provider's voicemail be better?

Better than what?  For your PHS, it's the only answering
machine option you have.  I think it works pretty well.

> 4. Which is the best PHS company?

I used to have Astel and now have DDI, and I prefer DDI.
They're bigger and seem to have better coverage than Astel.
My DDI PHS works in a lot of places that my Astel didn't.
Granted, they are all constantly adding more cells to their
networks, so this difference may not be as great as it once
was, but I still favor DDI.  That's why I don't have a phone
line: my PHS works in my house (very well), and my computers
are on a leased line, so I don't need a regular phone line.

> 5. Is a keitai an option for a mobile data PDA?

Cellular modems only communicate at 9600, whereas PIAFS and
Alpha Data32 are both 32K.  You don't want to use a cellular
phone for data communications if you don't have to.

> 7. They all use PIAFS?  So, is there anything else I would
>    need to consider before buying a PHS ISDN TA?

I don't know if any DDI phones do PIAFS or not.  As leader
of the Alpha Data32 camp, I'm not sure if they would want to
also support PIAFS or not.  Best to check before buying.

> 8. Does the NEC Aterm IW60 HS DSU have any competition?
>    (And, what does HS mean?)  It's a bit pricy, so I'd
>    like to be sure.

I wouldn't have anything but an NEC, myself.  Check their
whole product line and make sure this is the best one for
your needs, though.  How much is that model?

> 9. When using any of the PDAs to call an ISP equiped with
>    a PIAFS TA or to call my own PIAFS TA, I would pay the
>    same as a PHS voice call?  (plus regular ISP usage fee)
>    Since many ISPs offer 64K ISDN dialup at the same rate
>    as analog, do they charge extra to do PIAFS on the
ISDN?

Speaking only for the ISP I work for, no, there is no extra
charge for using PIAFS.  I don't know if others charge for
it or not, but I don't think so. AFAIK, the data comm rate
on a PHS is the same as the voice rate, but ask the PHS
company before buying, just to make sure.


I hope this helps answer some of your questions, and I'm
sure others will add to it.

Cheers,

Jonathan

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