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Wireless connections, trace them in a LAN?

Hi all,
I am about to distribute an A97-runtime app. which will be used on a LAN by approx. 30 users.
The network is pretty good, but there are a few managers who have wireless laptops...
Of course they also want to access the db.

I am a bit afraid of possible corruption due to the wireless connections.
==> Do I have to be afraid indeed?
If so, what is the best way to deal with this?
Should I trace the wireless connections (possible?) and force them into a read-only mode?

Thanks,
Arno R
Mar 5 '06 #1
45 2895
On Sun, 5 Mar 2006 16:37:31 +0100, "Arno R" <ar***********@tiscali.nl>
wrote:

I would be concerned as well. I sometimes use Access applications at
the office on my tablet PC. One of them doesn't even come up and gives
some error I still need to debug. The other thing is that when the
machine is idle for a minute or two, it shuts down the network
connection. All in all I don't think the designers of Access had this
in mind when they wrote the engine, and I am indeed concerned about
corruption.

-Tom.

Hi all,
I am about to distribute an A97-runtime app. which will be used on a LAN by approx. 30 users.
The network is pretty good, but there are a few managers who have wireless laptops...
Of course they also want to access the db.

I am a bit afraid of possible corruption due to the wireless connections.
==> Do I have to be afraid indeed?
If so, what is the best way to deal with this?
Should I trace the wireless connections (possible?) and force them into a read-only mode?

Thanks,
Arno R


Mar 5 '06 #2
"Arno R" <ar***********@tiscali.nl> wrote in
news:44**********************@text.nova.planet.nl:
I am about to distribute an A97-runtime app. which will be used on
a LAN by approx. 30 users. The network is pretty good, but there
are a few managers who have wireless laptops... Of course they
also want to access the db.
They can't unless you can provide Windows Terminal Server for them
to work remotely. Wireless LANs are just too unreliable for Access
-- it would choke repeatedly on any WiFi network I've ever worked
on.
I am a bit afraid of possible corruption due to the wireless
connections.
==> Do I have to be afraid indeed?
I would never, ever allow users to run an Access app across a
wireless connection.
If so, what is the best way to deal with this?
Should I trace the wireless connections (possible?) and force them
into a read-only mode?


There is simply no way to do it unless you change the back end to a
server database. I would suggest Terminal Server in this kind of
situation.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 5 '06 #3
I am a bit afraid of possible corruption due to the wireless connections. ==> Do I have to be afraid indeed?

yes....I have some diagrams as to WHY the mdb file will currupt here...

http://www.members.shaw.ca/AlbertKallal//Wan/Wans.html

If so, what is the best way to deal with this?


Use one of the methods suggested in the above article....

--
Albert D. Kallal (Access MVP)
Edmonton, Alberta Canada
pl*****************@msn.com
http://www.members.shaw.ca/AlbertKallal
Mar 5 '06 #4
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better not use them
(However my client is not 'very' pleased with this message...;-) )

So the question remains how to 'deal' with the laptop-users
I would rather not go the synchronisation-route with them. I have the impression that would still be risky (and difficult).
Concerning Terminal Services:
Is it possible for the 25-30 users to run the app over the wired LAN while the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS before for ALL users)

Concerning tracing the wireless-ones:
I can simply trace the machine-name and deny access,
But maybe (I will investigate this) the laptops could also use a wired-connection to the LAN, since I believe they also have a 'normal' network card.
In that case I can't simply deny access for the machine, but need to detect when they incidently connect to the db wireless

Arno R
Mar 6 '06 #5
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better not use them
(However my client is not 'very' pleased with this message...;-) )

So the question remains how to 'deal' with the laptop-users
I would rather not go the synchronisation-route with them. I have the impression that would still be risky (and difficult).
Concerning Terminal Services:
Is it possible for the 25-30 users to run the app over the wired LAN, while only the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS before for ALL users)

Concerning tracing the wireless-ones:
I can simply trace the machine-name and deny access,
But maybe (I will investigate this) the laptops could also use a wired-connection to the LAN, since I believe they also have a 'normal' network card.
In that case I can't simply deny access for the machine, but need to detect when they incidently connect to the db wireless

Arno R
Mar 6 '06 #6
Ted
Seems to me your only option, to assure integrity of the data for you
application with the WiFi laptops would be to go with Replication.

Arno R wrote:
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better not use them
(However my client is not 'very' pleased with this message...;-) )

So the question remains how to 'deal' with the laptop-users
I would rather not go the synchronisation-route with them. I have the impression that would still be risky (and difficult).
Concerning Terminal Services:
Is it possible for the 25-30 users to run the app over the wired LAN, while only the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS before for ALL users)

Concerning tracing the wireless-ones:
I can simply trace the machine-name and deny access,
But maybe (I will investigate this) the laptops could also use a wired-connection to the LAN, since I believe they also have a 'normal' network card.
In that case I can't simply deny access for the machine, but need to detect when they incidently connect to the db wireless

Arno R


Mar 6 '06 #7
>Concerning Terminal Services:
Is it possible for the 25-30 users to run the app over the wired LAN, while
only the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS before
for ALL users)

Yes...and, if you are running windows 2000 server (or 03), then you can use
two free remote users. (included free with windows server).

Just remember, those TS users each need to have their own logon, and they
each get their own front end on the server.....

If you need more then 2 users, then licensing things kick in for TS...and it
starts to get expensive real fast.....
--
Albert D. Kallal (Access MVP)
Edmonton, Alberta Canada
pl*****************@msn.com
http://www.members.shaw.ca/AlbertKallal

Mar 6 '06 #8
Arno R wrote:
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better not use them
(However my client is not 'very' pleased with this message...;-) )


I was fascinated with this. I notice no one reported corruption, just
that it was sure to happen.

It seems to me that I did my own personal accounts for years with the
backend linked over a wireless connection, but perhaps my memory is
deceiving me. Then again I may have been using Transactions and that
may have had something to do with my having zero problems.

So I found an old mdb and put it in a shared documents folder on
another computer. I created a new db on my computer and linked to all
the tables in the db on the "remote = next room" computer. Then I
created an auto form. The auto form is open right now.

I disabled my wired connection and enabled my wireless connection. Just
to be sure I pulled the wire. I know this isn't a WAN but it is a
wireless connection and the links are subject to the slings and arrows
of outrageous wireless slowness, dropsy and other diseases.

I've been working all day and plan to take a break now. I'll leave the
Form open. My computer will go to sleep, and so will the one where the
back end is. Will there be corruption? I have no idea, but I'll let ya
know.

Mar 6 '06 #9
"Ted" <be*****@gmail.com> wrote in
news:11**********************@i40g2000cwc.googlegr oups.com:
Seems to me your only option, to assure integrity of the data for
you application with the WiFi laptops would be to go with
Replication.


I would never advocate replication for a scenario like Arno's. I
would only recommend Terminal Server. The only situation where
replication is still warranted is, in my opinion, when the users
have to operate for significant periods of time without a network
connection of any kind (LAN or Internet/WAN).

In this case, Arno is replacing a LAN connection, not disconnected
users. Replication would be way too much work for that situation, in
my opinion, because you couldn't use DIRECT replication (the easy
kind), since the connection is not reliable -- you'd have to use
indirect, which is complicated to set up and requires daily
attention to keep running smoothly.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 6 '06 #10
"Arno R" <ar***********@tiscali.nl> wrote in
news:44**********************@text.nova.planet.nl:
Is it possible for the 25-30 users to run the app over the wired
LAN, while only the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS
before for ALL users)


I don't quite get what the issue is in your mind. I have one app
running with 3 or 4 users in the main office connecting via LAN and
about 10 users in remote offices running the same app over TS. There
are no problems. As long as you link your tables in your front end
using UNC path, it will run just fine either on the TS or on the
LAN.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 6 '06 #11
"Albert D. Kallal" <ka****@msn.com> wrote in
news:cf%Of.110541$sa3.1288@pd7tw1no:
Yes...and, if you are running windows 2000 server (or 03), then
you can use two free remote users. (included free with windows
server).


Only if you make those users part of the administrators group on the
server, which most sysadmins would not be willing to do. That's
because those two free TS logins are included only for remote
administration.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 6 '06 #12
"Albert D. Kallal" <ka****@msn.com> wrote in
news:cf%Of.110541$sa3.1288@pd7tw1no:
If you need more then 2 users, then licensing things kick in for
TS...and it starts to get expensive real fast.....


No, it doesn't. If the client machines already have Office installed
on them, it costs only about $40/user or PC in CALs. It's not
expensive at all, in my opinion. It's much cheaper than the
administrative cost of deploying an Access app on remote machines.
It's much cheaper than re-engineering an app to use Replication.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 6 '06 #13
Isn't it interesting that you don't find any of your "pals", John Marshall,
Keith Wilby, Rob Oldfield or Randy Harris helping you out!!!!
"Arno R" <ar***********@tiscali.nl> wrote in message
news:44**********************@text.nova.planet.nl. ..
Hi all,
I am about to distribute an A97-runtime app. which will be used on a LAN by
approx. 30 users.
The network is pretty good, but there are a few managers who have wireless
laptops...
Of course they also want to access the db.

I am a bit afraid of possible corruption due to the wireless connections.
==> Do I have to be afraid indeed?
If so, what is the best way to deal with this?
Should I trace the wireless connections (possible?) and force them into a
read-only mode?

Thanks,
Arno R
Mar 6 '06 #14
Lyle Fairfield wrote:
the slings and arrows
of outrageous
I resemble that remark :-).
dropsy
:-).

I've been working all day and plan to take a break now. I'll leave the
Form open. My computer will go to sleep, and so will the one where the
back end is. Will there be corruption? I have no idea, but I'll let ya
know.


Although I am interested in your datapoint, a lack of corruption for
your connection would not prove much. It may supply hope. I'm not
ready to recommend connecting Access to a BE using wireless yet
although some people where I work have tried it without any trouble.
Plus, for example, the fact that my cellphone doesn't disconnect calls
doesn't necessarily imply that any one else's doesn't disconnect calls.

James A. Fortune
CD********@FortuneJames.com

Mar 6 '06 #15
You are quite right! Just because I have seen no leprechauns does not
mean there are no leprechauns. You should just go on believing that
leprechauns exist.
But you will forgive me, I hope, if I do not take into account the
existence of leprechauns in making decisions about my own life.
There is no point in agreeing with a man who thinks that 99% of the
bugs, problems, flaws and corruption that are described here are due
entirely to someone or many ones doing extremely stupid things.
Everyone should continue in his/her state of advanced paranoia. Pay no
attention to that man behind the curtain. He thinks that the cure to
almost all the troubles with Access that are reported is encapsulated
in three little words, "Learn your Trade!"

Mar 6 '06 #16
Well, so far I've disabled the connection, pulled out the power switch,
spilled some beer on the keyboard and downloaded a 61 meg file while my
form is open and I was trying to update some records. There is no
corruption yet.
Well it's only two hours. And this is Canada! All that fresh air and
those mom-baked apple pies probably make Access run better than in
other parts of the world!

Mar 6 '06 #17

"Steve" <no****@nospam.spam> schreef in bericht news:h9*****************@newsread1.news.atl.earthl ink.net...
Isn't it interesting that you don't find any of your "pals", John Marshall,
Keith Wilby, Rob Oldfield or Randy Harris helping you out!!!!


No not interesting at all Steve.
But feel free to explain your problem here.

Arno R
Mar 6 '06 #18
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@j33g2000cwa.googlegr oups.com:
Arno R wrote:
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better
not use them (However my client is not 'very' pleased with this
message...;-) )
I was fascinated with this. I notice no one reported corruption,
just that it was sure to happen.


You're going to lose the connection occasionally, and we all know
what Access does when it loses the network connection. Losing the
wireless connection is no different than pulling the network cable
on a wired network -- DISK OR NETWORK ERROR. This is an error Access
*never* recovers from, even if there's no corruption of the back
end.

So, even if it were somehow "safe" from corruption, it would still
be incredibly inconvenient for the end users to frequently encounter
the unrecoverable DISK OR NETWORK ERROR.

[]
I've been working all day and plan to take a break now. I'll leave
the Form open. My computer will go to sleep, and so will the one
where the back end is. Will there be corruption? I have no idea,
but I'll let ya know.


This may depend entirely on your WiFi environment. If you live in a
location where there's only one available network to connect to, and
no interference from competing devices (cordless phones, etc.),
you're likely to have no dropped connections.

In a city, it's very different.

I have one client whose WiFi connection goes up and down all day
long. They live and work in a large apartment building on
Manhattan's Upper Westside, and mostly, it's transparent -- it goes
down momentarily and comes back up almost immediately. They've
switched their base channel a couple of times and this does seem to
help.

But I'd never set them up to edit across the wireless connection.
They have a laptop with a wireless NIC and the wireless connection
is used only for Internet access. Their data file is replicated so
edits on the laptop are synched with the main database via a wired
network connection.

Yes, a wired connection can be interrupted, too, but it's
substantially more robust.

Now, it could be that different WiFi standards other than 802.11b
are more reliable (though I'd doubt that ones like 802.11g, which
uses the same radio spectrum as 802.11b, just more channels at
once). Perhaps 802.11a and the newer standards are more reliable. I
would expect a relationship between bandwidth and speed, so perhaps
one day wireless connections will be reliable enough for Access
applications.

But I wouldn't recommend it to any of my clients today.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 7 '06 #19
Br
Lyle Fairfield wrote:
You are quite right! Just because I have seen no leprechauns does not
mean there are no leprechauns. You should just go on believing that
leprechauns exist.
But you will forgive me, I hope, if I do not take into account the
existence of leprechauns in making decisions about my own life.
There is no point in agreeing with a man who thinks that 99% of the
bugs, problems, flaws and corruption that are described here are due
entirely to someone or many ones doing extremely stupid things.
Everyone should continue in his/her state of advanced paranoia. Pay no
attention to that man behind the curtain. He thinks that the cure to
almost all the troubles with Access that are reported is encapsulated
in three little words, "Learn your Trade!"


I guess to do some real testing you'd have to make your wireless environment
a little less friendly? Interference, extended range....?
--
regards,

Br@dley
Mar 7 '06 #20
David W. Fenton wrote:
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@j33g2000cwa.googlegr oups.com:
Arno R wrote:
Thanks much to all who responded.
The message is clear: wireless connections will be risky. Better
not use them (However my client is not 'very' pleased with this
message...;-) )
I was fascinated with this. I notice no one reported corruption,
just that it was sure to happen.


You're going to lose the connection occasionally, and we all know
what Access does when it loses the network connection. Losing the
wireless connection is no different than pulling the network cable
on a wired network -- DISK OR NETWORK ERROR. This is an error Access
*never* recovers from, even if there's no corruption of the back
end.


I'm not sure what you mean by "*never* recovers from". The error
doesn't seem to cause any significant problem here.
So, even if it were somehow "safe" from corruption, it would still
be incredibly inconvenient for the end users to frequently encounter
the unrecoverable DISK OR NETWORK ERROR.
Gee this has happened several times already. I just close and reopen
the form and "Presto", everything is back to normal.
I've been working all day and plan to take a break now. I'll leave
the Form open. My computer will go to sleep, and so will the one
where the back end is. Will there be corruption? I have no idea,
but I'll let ya know.


This may depend entirely on your WiFi environment. If you live in a
location where there's only one available network to connect to, and
no interference from competing devices (cordless phones, etc.),
you're likely to have no dropped connections.


Well there are a bunch of networks visible around here and a ton of
cell phones. No corruption yet though.
In a city, it's very different.

I have one client whose WiFi connection goes up and down all day
long. They live and work in a large apartment building on
Manhattan's Upper Westside, and mostly, it's transparent -- it goes
down momentarily and comes back up almost immediately. They've
switched their base channel a couple of times and this does seem to
help.

But I'd never set them up to edit across the wireless connection.
They have a laptop with a wireless NIC and the wireless connection
is used only for Internet access. Their data file is replicated so
edits on the laptop are synched with the main database via a wired
network connection.

Yes, a wired connection can be interrupted, too, but it's
substantially more robust.

Now, it could be that different WiFi standards other than 802.11b
are more reliable (though I'd doubt that ones like 802.11g, which
uses the same radio spectrum as 802.11b, just more channels at
once). Perhaps 802.11a and the newer standards are more reliable. I
would expect a relationship between bandwidth and speed, so perhaps
one day wireless connections will be reliable enough for Access
applications.


I'm using 802.11 g.

Mar 7 '06 #21
Oh now I get it. It isn't that wireless leads to corruption. It's that
"less than friendly" wireless leads to corruption. Right!
What'll I do about that? How's about I fly the whole thing over to
Australia where it will have to operate upside-down? That should be a
test!
Or how about I blaspheme a bit more than usual? All those thunderbolts
that God will throw down will surely cause some interference, if not
incineration.
But why?. I've already lost the wireless connection several times with
no corruption and no problems with recovery; just close the form and
reopen it.
Are connections lost because of Interference or ExtendedRange more
destructive than connections lost for who knows why?

Mar 7 '06 #22
They all want to kiss your A#@#&& but none offer any help to you!!!

"Arno R" <ar***********@tiscali.nl> wrote in message
news:44**********************@text.nova.planet.nl. ..

"Steve" <no****@nospam.spam> schreef in bericht
news:h9*****************@newsread1.news.atl.earthl ink.net...
Isn't it interesting that you don't find any of your "pals", John
Marshall,
Keith Wilby, Rob Oldfield or Randy Harris helping you out!!!!


No not interesting at all Steve.
But feel free to explain your problem here.

Arno R
Mar 7 '06 #23
Br
Lyle Fairfield wrote:
David W. Fenton wrote:
"Lyle Fairfield" <ly***********@aim.com> wrote in <> So, even if it were somehow "safe" from corruption, it would still
be incredibly inconvenient for the end users to frequently encounter
the unrecoverable DISK OR NETWORK ERROR.


Gee this has happened several times already. I just close and reopen
the form and "Presto", everything is back to normal.


I suspect if you're running code that is doing a lot of data intensive
operations, or multiple users, you'd be more likely to encounter corruption
if the connection is closed?

<>
--
regards,

Br@dley
Mar 7 '06 #24
Br
Lyle Fairfield wrote:
Oh now I get it. It isn't that wireless leads to corruption. It's that
"less than friendly" wireless leads to corruption. Right!
What'll I do about that? How's about I fly the whole thing over to
Australia where it will have to operate upside-down? That should be a
test!
Or how about I blaspheme a bit more than usual? All those thunderbolts
that God will throw down will surely cause some interference, if not
incineration.
The sad thing is you think you are funny.
But why?. I've already lost the wireless connection several times with
no corruption and no problems with recovery; just close the form and
reopen it.
I simply suggested a more realistic testing regime. There are many other
issues other than a simply disconnection, eg. packet loss, signal quality,
etc.
Are connections lost because of Interference or ExtendedRange more
destructive than connections lost for who knows why?


I didn't say they were. I just said they are some typical causes of network
problems and would therefore be things one should include in their testing
regime.
--
regards,

Br@dley
Mar 7 '06 #25
Lyle Fairfield wrote:
Oh now I get it. It isn't that wireless leads to corruption. It's that
"less than friendly" wireless leads to corruption. Right!
What'll I do about that? How's about I fly the whole thing over to
Australia where it will have to operate upside-down? That should be a
test!
Or how about I blaspheme a bit more than usual? All those thunderbolts
that God will throw down will surely cause some interference, if not
incineration.
But why?. I've already lost the wireless connection several times with
no corruption and no problems with recovery; just close the form and
reopen it.
Are connections lost because of Interference or ExtendedRange more
destructive than connections lost for who knows why?


You probably won't find any Leprechauns in Australia either :-).
You're free to come up with whatever conclusions are warranted by your
risk assessment. I'm not trying to give you a hard time Lyle. I don't
think I'm even disagreeing with you. Access over wireless may be
perfectly safe. I'm saying that I want to see plenty of reports of
Leprechaun-free environments before I assume that they don't exist.
Maybe Leprechauns are the result of poor programming practices, as you
suggest. Maybe not. I think we need more information about using
marginal wireless connections with Access. From personal experience I
know that when the network cable is pulled out while people are
connected, it usually results in no harm to the BE and in occasional
corruption to the FE. Where I work, some of the inspection stations
are rolled to different locations. In spite of several wireless
"access" points, there are places where the signal gets fairly weak. I
have asked management to limit using Access over wireless connections
until I hear more about other's experiences. I also ask the users not
to pull out the network cable while connected to Access :-).

James A. Fortune
CD********@FortuneJames.com

Mar 7 '06 #26
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@j52g2000cwj.googlegr oups.com:
David W. Fenton wrote:
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@j33g2000cwa.googlegr oups.com:
> Arno R wrote:
>> Thanks much to all who responded.
>> The message is clear: wireless connections will be risky.
>> Better not use them (However my client is not 'very' pleased
>> with this message...;-) )
>
> I was fascinated with this. I notice no one reported
> corruption, just that it was sure to happen.


You're going to lose the connection occasionally, and we all know
what Access does when it loses the network connection. Losing the
wireless connection is no different than pulling the network
cable on a wired network -- DISK OR NETWORK ERROR. This is an
error Access *never* recovers from, even if there's no corruption
of the back end.


I'm not sure what you mean by "*never* recovers from". The error
doesn't seem to cause any significant problem here.


I've never used a version of Access connected to a Jet back end that
can recover from the error -- it just keeps coming up, in an endless
loop, and you're able to close any forms or re-initialize the app.
The only solution is to close the app.

Now, an app could be engineered to get around this if it were
completely unbound. I'm not sure what happens there, to be honest,
as I don't use enough unbound forms to have ever encountered this
error in that situation. I'd think you'd have to be in a pure
unbound context for it to make any difference.

And, of course, if you're connected to SQL Server and not Jet, you
probably wouldn't encounter it.

But we were talking about Access to Jet, so that's not a relevant
point.
So, even if it were somehow "safe" from corruption, it would
still be incredibly inconvenient for the end users to frequently
encounter the unrecoverable DISK OR NETWORK ERROR.


Gee this has happened several times already. I just close and
reopen the form and "Presto", everything is back to normal.


I've never encountered a situation where that was possible. The
error message is modal, so you can't close the form while it is
onscreen, and pops up again as soon as it is dismissed, before you
have any chance to close the offending form.
> I've been working all day and plan to take a break now. I'll
> leave the Form open. My computer will go to sleep, and so will
> the one where the back end is. Will there be corruption? I have
> no idea, but I'll let ya know.


This may depend entirely on your WiFi environment. If you live in
a location where there's only one available network to connect
to, and no interference from competing devices (cordless phones,
etc.), you're likely to have no dropped connections.


Well there are a bunch of networks visible around here and a ton
of cell phones. No corruption yet though.


What version of Access? What is the back end? Bound or unbound
forms?
In a city, it's very different.

I have one client whose WiFi connection goes up and down all day
long. They live and work in a large apartment building on
Manhattan's Upper Westside, and mostly, it's transparent -- it
goes down momentarily and comes back up almost immediately.
They've switched their base channel a couple of times and this
does seem to help.

But I'd never set them up to edit across the wireless connection.
They have a laptop with a wireless NIC and the wireless
connection is used only for Internet access. Their data file is
replicated so edits on the laptop are synched with the main
database via a wired network connection.

Yes, a wired connection can be interrupted, too, but it's
substantially more robust.

Now, it could be that different WiFi standards other than 802.11b
are more reliable (though I'd doubt that ones like 802.11g, which
uses the same radio spectrum as 802.11b, just more channels at
once). Perhaps 802.11a and the newer standards are more reliable.
I would expect a relationship between bandwidth and speed, so
perhaps one day wireless connections will be reliable enough for
Access applications.


I'm using 802.11 g.


That might make a difference. I've only seen the really unreliable
network on 802.11a.

Of course, if you're sharing airspace with 802.11b networks, you're
not really getting the full benefit of the extra bandwidth.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 7 '06 #27
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@u72g2000cwu.googlegr oups.com:
Oh now I get it. It isn't that wireless leads to corruption. It's
that "less than friendly" wireless leads to corruption. Right!
No, it's that dropped connections while an edit is in process can
lead to connection. That's true of a wired or wireless connection.
The fact that wireless connections often blink on and off in the
course of regular operation means that the network connectivity is
intermittent, which greatly increases the opportunity for the
connection to be lost in an unrecoverable situation for Access
(i.e., DISK OR NETWORK ERROR) and/or corrupt the back end (whether
or not it's real corruption or just the suspect flag that leads to
the corruption warning message for other users trying to connect to
the back end).

[]
. . . I've already lost the wireless connection several times with
no corruption and no problems with recovery; just close the form
and reopen it.
I'd like to know more about your operating environment, e.g., what
version of Access, MDB or ADP, Jet or SQL Server back end, bound or
unbound forms. If you're in an ADP or an MDB running against SQL
Server, then you're not actually testing the conditions we were
talking about (Access front end to Jet back end), so your reports
really aren't even relevant (though they do provide one workaround
for a situation where the wireless network is required).
Are connections lost because of Interference or ExtendedRange more
destructive than connections lost for who knows why?


Perhaps you engineer your apps as a matter of course in a way that
avoids the problem. If so, I'd like to know what those methods are.
I, for one, have never encountered a DISK OR NETWORK ERROR that did
not require force quitting Access and reloading the app. That
doesn't always corrupt the back end, but it's a dangerous thing to
encounter and I wouldn't want to run in such an environment on a
regular basis.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 7 '06 #28
CD********@FortuneJames.com wrote in
news:11**********************@i40g2000cwc.googlegr oups.com:
I think we need more information about using
marginal wireless connections with Access. From personal
experience I know that when the network cable is pulled out while
people are connected, it usually results in no harm to the BE and
in occasional corruption to the FE.


Is the DISK OR NETWORK ERROR recoverable in your apps? I've never
seen one that does not require force quitting the app.

That's all I need to know -- a dropped network connection, whether
because of a pulled wired network cable or because of a wireless
connection loss, would lead to that error, and whether or not it
corrupts the back end in all cases (or even in a majority of cases),
seems not to be a desirable environment in which to purposely choose
to run an Access app.

And it just seems foolish to me to run the risk of corruption. We
know that under the right circumstances a dropped connection will
corrupt the back end (whether or not it leads to data loss is
irrelevant -- a back end marked suspect will prohibit new users from
opening it). Why run the app in an environment in which you know for
a fact that dropped connections are going to happen on a regular
basis?

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 7 '06 #29
I took my personal transactions (finance) AC97 backend and put it in
the Shared Files Folder of another computer on my network. I created a
new AC2003 db on my own personal laptop. I "joined" the network via
wireless. I linked to (not imported) the Backend Tables using the
Import Data thingme. So this is all DAO and Access. I asked the wizard
to make a form for the Transactions Table. I opened the Form. I fooled
around, updating and appending. I got DISK OR NETWORK ERROR several
times. When I did I closed the form and reopened it. I did not have to
close the db. Everything worked swimmingly. I had supper. The wireless
connection was dropped. I came back and when I tried to scroll past
about 50 records there was that DISK OR NETWORK ERROR again. But same
solution (the connection had picked up of course) ... just close and
reopen the form.
Tomorrow, if I have time I'll create another form with its timer set to
say, one minute. It will open the form already described, scroll to
some random record, do some trivial update of its fields and save the
edited record. Then it will add a new record and save that. Then it
will delete a record. Then it will close the form. In another minute it
will start all over.
I'll report the results; if they're OK I'll try to come up with some
continual updating of the table and I'll close the connection in the
middle of that. I'll do that several times.
I'll report the results.

Mar 7 '06 #30
"Lyle Fairfield" <ly***********@aim.com> wrote in
news:11**********************@i40g2000cwc.googlegr oups.com:
I took my personal transactions (finance) AC97 backend and put it in
the Shared Files Folder of another computer on my network. I created a
new AC2003 db on my own personal laptop. I "joined" the network via
wireless. I linked to (not imported) the Backend Tables using the
Import Data thingme. So this is all DAO and Access. I asked the wizard
to make a form for the Transactions Table. I opened the Form. I fooled
around, updating and appending. I got DISK OR NETWORK ERROR several
times. When I did I closed the form and reopened it. I did not have to
close the db. Everything worked swimmingly. I had supper. The wireless
connection was dropped. I came back and when I tried to scroll past
about 50 records there was that DISK OR NETWORK ERROR again. But same
solution (the connection had picked up of course) ... just close and
reopen the form.
Tomorrow, if I have time I'll create another form with its timer set to
say, one minute. It will open the form already described, scroll to
some random record, do some trivial update of its fields and save the
edited record. Then it will add a new record and save that. Then it
will delete a record. Then it will close the form. In another minute it
will start all over.
I'll report the results; if they're OK I'll try to come up with some
continual updating of the table and I'll close the connection in the
middle of that. I'll do that several times.
I'll report the results.


BTW I'll leave the form open all night. In the morning we'll see if I have
to close the db, or just the form.

--
Lyle Fairfield
Mar 7 '06 #31
"David W. Fenton" <XX*******@dfenton.com.invalid> wrote in message
news:Xn*********************************@127.0.0.1 ...
[snip]
If you're in an ADP or an MDB running against SQL
Server, then you're not actually testing the conditions we were
talking about (Access front end to Jet back end), so your reports
really aren't even relevant (though they do provide one workaround
for a situation where the wireless network is required).


Actually in my experience ODBC errors due to a temporarily dropped connection
also do not "self heal" most of the time. One normally has to close Access and
then reopen to get the connection back. I would have actually expected Jet to
be the more tolerant one in that regard. Not more tolerant in terms of
potentially bad things happening to the data, but in recovering without a
restart.
--
I don't check the Email account attached
to this message. Send instead to...
RBrandt at Hunter dot com

Mar 7 '06 #32

"Albert D. Kallal" <ka****@msn.com> schreef in bericht news:cf%Of.110541$sa3.1288@pd7tw1no...
Concerning Terminal Services:

Is it possible for the 25-30 users to run the app over the wired LAN, while
only the two managers with the wireless laptops use TS?
How to setup this scenario? Is this even possible? (I only used TS before
for ALL users)

Yes...and, if you are running windows 2000 server (or 03), then you can use
two free remote users. (included free with windows server).


This will be a good alternative then.
I know the cliŽnt 'has' Windows 2000 server.
Will talk with the admin guys later this week.

Thanks
Arno R
Mar 7 '06 #33

"David W. Fenton" <XX*******@dfenton.com.invalid> schreef in bericht news:Xn**********************************@127.0.0. 1...
"Albert D. Kallal" <ka****@msn.com> wrote in
news:cf%Of.110541$sa3.1288@pd7tw1no:
If you need more then 2 users, then licensing things kick in for
TS...and it starts to get expensive real fast.....


No, it doesn't. If the client machines already have Office installed
on them, it costs only about $40/user or PC in CALs. It's not
expensive at all, in my opinion. It's much cheaper than the
administrative cost of deploying an Access app on remote machines.
It's much cheaper than re-engineering an app to use Replication.


Why is the Office installation relevant here?
I am deploying the runtime version of Access97 to this cliŽnt.

Thanks,
Arno R
Mar 7 '06 #34
"Lyle Fairfield" <ly***********@aim.com> schreef in bericht news:11**********************@i40g2000cwc.googlegr oups.com...
I'll report the results; if they're OK I'll try to come up with some
continual updating of the table and I'll close the connection in the
middle of that. I'll do that several times.
I'll report the results.


Hi Lyle, I am interested in your testing results.
Will do some tests myself also, connecting my laptop (wireless ) to my 'server' here.
I will use 802.11 g.
It might help me to know that connecting to the db (wireless) without any real data-entry will do no harm.
I can force the 'wireless-laptop-users' to a read-only-mode if necessary.
If this is a 'sound' possibility I can discuss this as an option.
Since the managers are mostly 'looking' at data it might be no problem for them open the db read-only.

But I will discuss the TS-option also, since I know they have Windows Server 2000.

Thanks.

Arno R
Mar 7 '06 #35
"Steve" <no****@nospam.spam> wrote in message
news:h9*****************@newsread1.news.atl.earthl ink.net...
Isn't it interesting that you don't find any of your "pals", John
Marshall, Keith Wilby, Rob Oldfield or Randy Harris helping you out!!!!


Unlike you, I don't post replies to questions on which I have no knowledge.

Keith.
Mar 7 '06 #36
So in the morning I closed the form and reopened it. All's fine.

At thismoment I have opened another form. Every second it opens the
Transactions Form (linked via wireless) navigates to the "next" record,
reverses the string in the Details field, saves the Record, and closes
the form, showing what's happening in its own text controls, as below.
So far, about 10 minutes or 600 openings and updatings, no problem.

Private Sub Form_Load()
With DoCmd
.Restore
.RunCommand acCmdSizeToFitForm
End With
End Sub

Private Sub Form_Open(Cancel As Integer)
With Me
.TimerInterval = 1000
End With
End Sub

Private Sub Form_Timer()
Static MyCounter
Dim rs As DAO.Recordset
With Form_TransActions
Set rs = .RecordsetClone
With rs
.MoveLast
If MyCounter = .RecordCount Then
MyCounter = 1
Else
MyCounter = MyCounter + 1
End If
.MoveFirst
.Move MyCounter
End With
.Bookmark = rs.Bookmark
Me.TxtMyCounter.Value = MyCounter
Me.txtDetails.Value = .Details.Value
Me.txtDetailsReversed.Value = StrReverse(.Details.Value)
.Details.Value = Me.txtDetailsReversed.Value
.Dirty = False
End With
Set rs = Nothing
DoCmd.Close acForm, "Transactions"
End Sub

Mar 7 '06 #37
Well, this has been churning away for a few hours now. And having
become bored with it, I have turned it off. I can't find any problems
with linking to a backend via a wireless connection. I don't and
probably never will have a client who wants this; but I have no reason
to tell him/her "It can't be done" should that ever happen.

Mar 7 '06 #38

"Lyle Fairfield" <ly***********@aim.com> schreef in bericht news:11**********************@u72g2000cwu.googlegr oups.com...
Well, this has been churning away for a few hours now. And having
become bored with it, I have turned it off. I can't find any problems
with linking to a backend via a wireless connection. I don't and
probably never will have a client who wants this; but I have no reason
to tell him/her "It can't be done" should that ever happen.


I also did some minor testing today.
When I started I had to relink the backend-tables (different path).
Access closed down two times... without any warning.

When the backend was linked succesfully (the third time succeeded) I also had no significant problems.
However I found the performance very slow compared to the wired situation. (Obviously)
I did not notice any speed issues at first.

So thanks for your testing and the different opinion Lyle.
I now have enough options to discuss later this week.

Arno R
Mar 7 '06 #39
"Rick Brandt" <ri*********@hotmail.com> wrote in
news:zt*******************@newssvr29.news.prodigy. net:
"David W. Fenton" <XX*******@dfenton.com.invalid> wrote in message
news:Xn*********************************@127.0.0.1 ...
[snip]
If you're in an ADP or an MDB running against SQL
Server, then you're not actually testing the conditions we were
talking about (Access front end to Jet back end), so your reports
really aren't even relevant (though they do provide one
workaround for a situation where the wireless network is
required).


Actually in my experience ODBC errors due to a temporarily dropped
connection also do not "self heal" most of the time. One normally
has to close Access and then reopen to get the connection back. I
would have actually expected Jet to be the more tolerant one in
that regard. Not more tolerant in terms of potentially bad things
happening to the data, but in recovering without a restart.


With Jet, it's the once-per-second pinging of the LDB file (or
whatever your refresh interval is) that causes Jet to crap out. I'd
expect ODBC to not do that, but only to crap out when a data request
is made and the connection is not there.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/
Mar 7 '06 #40
So, since you post very few replioes to questions, that must mean you have
very little knowledge!!!!!!!!!!
What an A#$&&$ you are!!!!!!!!!
"Keith Wilby" <he**@there.com> wrote in message
news:44********@glkas0286.greenlnk.net...
"Steve" <no****@nospam.spam> wrote in message
news:h9*****************@newsread1.news.atl.earthl ink.net...
Isn't it interesting that you don't find any of your "pals", John
Marshall, Keith Wilby, Rob Oldfield or Randy Harris helping you out!!!!


Unlike you, I don't post replies to questions on which I have no
knowledge.

Keith.

Mar 8 '06 #41
"Steve" <no****@nospam.spam> wrote in message
news:sH****************@newsread2.news.atl.earthli nk.net...
So, since you post very few replioes to questions, that must mean you have
very little knowledge!!!!!!!!!!
What an A#$&&$ you are!!!!!!!!!


Poor. 0/10. Stay behind after cl ass.
Mar 8 '06 #42
What an A#$&&$ you are!!!!!!!!!
"Keith Wilby" <he**@there.com> wrote in message
news:44**********@glkas0286.greenlnk.net...
"Steve" <no****@nospam.spam> wrote in message
news:sH****************@newsread2.news.atl.earthli nk.net...
So, since you post very few replioes to questions, that must mean you
have very little knowledge!!!!!!!!!!
What an A#$&&$ you are!!!!!!!!!


Poor. 0/10. Stay behind after cl ass.

Mar 8 '06 #43

"Steve" <no****@nospam.spam> schreef in bericht news:08****************@newsread3.news.atl.earthli nk.net...
What an A#$&&$ you are!!!!!!!!!


So this is going to be your new 'signature' Steve?
Man, you are improving! Chapeau!

Arno R
Mar 8 '06 #44
"Arno R" <ar***********@tiscali.nl> wrote in message
news:44**********************@text.nova.planet.nl. ..
"Steve" <no****@nospam.spam> schreef in bericht
news:08****************@newsread3.news.atl.earth link.net...
What an A#$&&$ you are!!!!!!!!!
So this is going to be your new 'signature' Steve?
Man, you are improving! Chapeau! Arno R


It would make more sense than "1150 people have paid me to do something I
know little about" ;-)

Keith.
Mar 9 '06 #45
Two A#$&&$s are a real pair!!!!

"Keith Wilby" <he**@there.com> wrote in message
news:44**********@glkas0286.greenlnk.net...
"Arno R" <ar***********@tiscali.nl> wrote in message
news:44**********************@text.nova.planet.nl. ..
"Steve" <no****@nospam.spam> schreef in bericht
news:08****************@newsread3.news.atl.eart hlink.net...
What an A#$&&$ you are!!!!!!!!!

So this is going to be your new 'signature' Steve?
Man, you are improving! Chapeau!

Arno R


It would make more sense than "1150 people have paid me to do something I
know little about" ;-)

Keith.

Mar 9 '06 #46

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