Discussion:
TC wifi initializtion - concept
(too old to reply)
Barry R Cisna
2014-04-05 11:01:41 UTC
Permalink
Hello All,

I asked this quite some time ago and didn't get any response so just
throwing this idea out again.
(Maybe there is a project doing what I would like to achieve with wifi
on tc's and I do not know of it,also?)

Situation,and hopefully a remedy:

1) At this point it seems that a big downfall of using tc's is no
bootable wifi initialization & association possibility with any
surrounding AP's in the boot process.

1a) Has anyone ever thought of incorporating an "option" by adding the
code in the system bios to add a parameter for wifi association to "an"
access point along with password if needed .

This would be very much the same scenario as when we used to add an
etherboot chip to the nics on tc's back in the day (before pxe became
prevelant), only using the "native" bios chip rather than an add on
chip.

In other words to get away from having to actually have an add
on,bootable media,onto any given TC system,,such as having to hang an
usb stick or slap a cd in to achieve wifi initialization and
association to a given AP.

It just seems very odd with the length of time,that wifi has been a
'must have' on any network device that a TC vendor has not even come up
with an spec for just this?

Thanks,
Barry
Burke Almquist
2014-04-05 16:39:34 UTC
Permalink
Post by Barry R Cisna
1) At this point it seems that a big downfall of using tc's is no
bootable wifi initialization & association possibility with any
surrounding AP's in the boot process.
1a) Has anyone ever thought of incorporating an "option" by adding the
code in the system bios to add a parameter for wifi association to "an"
access point along with password if needed .
This would be very much the same scenario as when we used to add an
etherboot chip to the nics on tc's back in the day (before pxe became
prevelant), only using the "native" bios chip rather than an add on
chip.
In other words to get away from having to actually have an add
on,bootable media,onto any given TC system,,such as having to hang an
usb stick or slap a cd in to achieve wifi initialization and
association to a given AP.
It just seems very odd with the length of time,that wifi has been a
'must have' on any network device that a TC vendor has not even come up
with an spec for just this?
Thanks,
Barry
I think there are two reasons that something like PXE/etherboot for wireless hasn’t happened.
1. It’s more complicated to do than ether boot/PXE because of the additional security/authentication requirements, and also less likely to be used since portablity means it might not have a boot server available to boot from.
2. The nature of wireless connections means that the bandwidth is shared and performance can vary enormously, unlike a properly wired connection which is switched and almost always runs at the rated speed. Thus you are extremely limited in the number of thin clients you can run over such a connection.

What I HAVE seen people do that don’t want to build large wired networks, is to use wireless to ethernet dongles for a small number of individual clients, or to use a cheep wifi router as a sort of bridge for multiple clients that can just plug into it wherever they set up. Using a router solves some signal strength and packet collision issues, though still not a good as having gigabit ethernet obviously.
Terrell Prude' Jr.
2014-04-08 02:54:30 UTC
Permalink
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago).
As much as the wireless hype may be going on now, there's just no way an
LTSP architecture can be successful on a hub, be that hub wireless or
wired. Well, not if you intend to use the full complement of
educational apps, that is. And don't even *think* about anything that
uses Flash, for the same reason.

LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.

--TP
Post by Barry R Cisna
Hello All,
I asked this quite some time ago and didn't get any response so just
throwing this idea out again.
(Maybe there is a project doing what I would like to achieve with wifi
on tc's and I do not know of it,also?)
1) At this point it seems that a big downfall of using tc's is no
bootable wifi initialization & association possibility with any
surrounding AP's in the boot process.
1a) Has anyone ever thought of incorporating an "option" by adding the
code in the system bios to add a parameter for wifi association to "an"
access point along with password if needed .
This would be very much the same scenario as when we used to add an
etherboot chip to the nics on tc's back in the day (before pxe became
prevelant), only using the "native" bios chip rather than an add on
chip.
In other words to get away from having to actually have an add
on,bootable media,onto any given TC system,,such as having to hang an
usb stick or slap a cd in to achieve wifi initialization and
association to a given AP.
It just seems very odd with the length of time,that wifi has been a
'must have' on any network device that a TC vendor has not even come up
with an spec for just this?
Thanks,
Barry
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For more info see <http://www.k12os.org>
Jeff Siddall
2014-04-08 14:43:09 UTC
Permalink
Post by Terrell Prude' Jr.
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago).
As much as the wireless hype may be going on now, there's just no way an
LTSP architecture can be successful on a hub, be that hub wireless or
wired. Well, not if you intend to use the full complement of
educational apps, that is. And don't even *think* about anything that
uses Flash, for the same reason.
LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.
I agree.

Wireless is just not cut out for _general_ LTSP use. You might find
some limited success for things like kiosks running everything as a
localapp but the use cases are relatively niche.

I have moved most of my clients to switched wired 1000 Mbps connections
because even dedicated 100 M connections were too slow for some things.
Also keep in mind that the apps that use a ton of bandwidth might not
be obvious. LibreOffice Impress was one of the applications that was
frequently unusable at 100 Mbps.

Jeff
Jim Kinney
2014-04-08 14:52:53 UTC
Permalink
Anything that uses the SDL toolkit for graphics is barely usable at 100Mbps
and less than 1GHz on the client cpu. Tuxmath is barely usable with a 1Gbps
network and a 1.5GHz client cpu.
Post by Jeff Siddall
Post by Terrell Prude' Jr.
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago).
As much as the wireless hype may be going on now, there's just no way an
LTSP architecture can be successful on a hub, be that hub wireless or
wired. Well, not if you intend to use the full complement of
educational apps, that is. And don't even *think* about anything that
uses Flash, for the same reason.
LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.
I agree.
Wireless is just not cut out for _general_ LTSP use. You might find some
limited success for things like kiosks running everything as a localapp but
the use cases are relatively niche.
I have moved most of my clients to switched wired 1000 Mbps connections
because even dedicated 100 M connections were too slow for some things.
Also keep in mind that the apps that use a ton of bandwidth might not be
obvious. LibreOffice Impress was one of the applications that was
frequently unusable at 100 Mbps.
Jeff
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--
--
James P. Kinney III

Every time you stop a school, you will have to build a jail. What you gain
at one end you lose at the other. It's like feeding a dog on his own tail.
It won't fatten the dog.
- Speech 11/23/1900 Mark Twain


*http://heretothereideas.blogspot.com/
<http://heretothereideas.blogspot.com/>*
Les Mikesell
2014-04-08 15:15:36 UTC
Permalink
Post by Jim Kinney
Anything that uses the SDL toolkit for graphics is barely usable at 100Mbps
and less than 1GHz on the client cpu. Tuxmath is barely usable with a 1Gbps
network and a 1.5GHz client cpu.
It would be interesting to test this with x2go to see if the screen
refreshes end up being usefully cached.
--
Les Mikesell
***@gmail.com
Les Mikesell
2014-04-08 15:13:44 UTC
Permalink
On Mon, Apr 7, 2014 at 9:54 PM, Terrell Prude' Jr.
Post by Terrell Prude' Jr.
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago). As
much as the wireless hype may be going on now, there's just no way an LTSP
architecture can be successful on a hub, be that hub wireless or wired.
Well, not if you intend to use the full complement of educational apps, that
is. And don't even *think* about anything that uses Flash, for the same
reason.
LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.
I don't think you'd want to network-boot over wifi, but has anyone
tried more than a few sessions of NX/freenx or x2go over wifi
simultaneously? I use it myself from a laptop frequently and think
it is great for everything short of streaming video but don't know how
well it scales. If you aren't familiar with the NX or x2go
technology, it adds proxy/caching/compression on both the server and
client sides to greatly reduce latency and the overall bandwidth
needed, and it has cross platform clients. Otherwise it appears as a
normal X desktop, adding the option to disconnect from running
sessions and reconnecting later with everything still running (even
from a different client).
--
Les Mikesell
***@gmail.com
Roger Nutbeam
2014-04-08 16:08:19 UTC
Permalink
I concur. Latency is just terrible on wireless.


On Mon, Apr 7, 2014 at 9:54 PM, Terrell Prude' Jr. <
Post by Terrell Prude' Jr.
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago). As
much as the wireless hype may be going on now, there's just no way an LTSP
architecture can be successful on a hub, be that hub wireless or wired.
Well, not if you intend to use the full complement of educational apps,
that is. And don't even *think* about anything that uses Flash, for the
same reason.
LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.
--TP
Post by Barry R Cisna
Hello All,
I asked this quite some time ago and didn't get any response so just
throwing this idea out again.
(Maybe there is a project doing what I would like to achieve with wifi
on tc's and I do not know of it,also?)
1) At this point it seems that a big downfall of using tc's is no
bootable wifi initialization & association possibility with any
surrounding AP's in the boot process.
1a) Has anyone ever thought of incorporating an "option" by adding the
code in the system bios to add a parameter for wifi association to "an"
access point along with password if needed .
This would be very much the same scenario as when we used to add an
etherboot chip to the nics on tc's back in the day (before pxe became
prevelant), only using the "native" bios chip rather than an add on
chip.
In other words to get away from having to actually have an add
on,bootable media,onto any given TC system,,such as having to hang an
usb stick or slap a cd in to achieve wifi initialization and
association to a given AP.
It just seems very odd with the length of time,that wifi has been a
'must have' on any network device that a TC vendor has not even come up
with an spec for just this?
Thanks,
Barry
_______________________________________________
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https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
_______________________________________________
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For more info see <http://www.k12os.org>
Roger Nutbeam
2014-04-08 16:10:48 UTC
Permalink
I've have some clients on regular desktops that have to run X over
wireless, and it just sucks. And this is only with a couple of desktops
using wireless.
Post by Roger Nutbeam
I concur. Latency is just terrible on wireless.
On Mon, Apr 7, 2014 at 9:54 PM, Terrell Prude' Jr. <
Post by Terrell Prude' Jr.
No way in heck I would want TC's on wireless. It's a hub. X11 screen
updates can suck up to 73 Mbit/sec when playing TuxType (I did this
measurement about 10 years ago and re-confirmed it about 5 years ago). As
much as the wireless hype may be going on now, there's just no way an LTSP
architecture can be successful on a hub, be that hub wireless or wired.
Well, not if you intend to use the full complement of educational apps,
that is. And don't even *think* about anything that uses Flash, for the
same reason.
LibreOffice'll work OK. So will Gedit or even Firefox, provided there
aren't a lot of screen updates. But relatively static (as far as screen
updates go) apps like that are about it. Putting LTSP on wireless is a
recipe for failure, given current wireless technology.
--TP
Post by Barry R Cisna
Hello All,
I asked this quite some time ago and didn't get any response so just
throwing this idea out again.
(Maybe there is a project doing what I would like to achieve with wifi
on tc's and I do not know of it,also?)
1) At this point it seems that a big downfall of using tc's is no
bootable wifi initialization & association possibility with any
surrounding AP's in the boot process.
1a) Has anyone ever thought of incorporating an "option" by adding the
code in the system bios to add a parameter for wifi association to "an"
access point along with password if needed .
This would be very much the same scenario as when we used to add an
etherboot chip to the nics on tc's back in the day (before pxe became
prevelant), only using the "native" bios chip rather than an add on
chip.
In other words to get away from having to actually have an add
on,bootable media,onto any given TC system,,such as having to hang an
usb stick or slap a cd in to achieve wifi initialization and
association to a given AP.
It just seems very odd with the length of time,that wifi has been a
'must have' on any network device that a TC vendor has not even come up
with an spec for just this?
Thanks,
Barry
_______________________________________________
K12OSN mailing list
https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
_______________________________________________
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https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
Les Mikesell
2014-04-08 16:22:53 UTC
Permalink
I've have some clients on regular desktops that have to run X over wireless,
and it just sucks. And this is only with a couple of desktops using
wireless.
Have you ever tried x2go or the NX client (either with their server or
freenx server-side?
--
Les Mikesell
***@gmail.com
Joseph Bishay
2014-04-08 16:35:00 UTC
Permalink
Hello,

I regularly use NX to connect to the LTSP server. I needed a way to
allow teachers to connect from home / outside school that would work
with high-latency wireless networks that they'd probably have at home.
They install the NX client at home and I'm running FreeNX on the
server and it works amazingly well. It's just as if they're sitting
at school. It is fantastic.

Joseph
Post by Les Mikesell
I've have some clients on regular desktops that have to run X over wireless,
and it just sucks. And this is only with a couple of desktops using
wireless.
Have you ever tried x2go or the NX client (either with their server or
freenx server-side?
--
Les Mikesell
_______________________________________________
K12OSN mailing list
https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
Roger Nutbeam
2014-04-08 16:30:11 UTC
Permalink
Freenx is a lot better performing than X over wireless. I haven't had the
chance to test x2go but from what I've looked it so far, I like what I see.
Post by Roger Nutbeam
Post by Roger Nutbeam
I've have some clients on regular desktops that have to run X over
wireless,
Post by Roger Nutbeam
and it just sucks. And this is only with a couple of desktops using
wireless.
Have you ever tried x2go or the NX client (either with their server or
freenx server-side?
--
Les Mikesell
_______________________________________________
K12OSN mailing list
https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
Les Mikesell
2014-04-08 16:50:50 UTC
Permalink
Post by Roger Nutbeam
Freenx is a lot better performing than X over wireless. I haven't had the
chance to test x2go but from what I've looked it so far, I like what I see.
X2go uses some of the same nx libraries as freenx and unlike NX the
clients are also open source. At least on CentOS6 freenx and x2go
packages can co-exist if you want to try both, although they don't
interoperate. X2go seems to have more active development now and
seems pretty usable. I think a USB-boot into something that just
opened an x2go window might be a practical thin client - but I haven't
run a large number of clients against the same server. There is
probably some overhead for the virtual sceen/cache/compression for
each session.
--
Les Mikesell
***@gmail.com
David L. Willson
2014-04-08 17:13:01 UTC
Permalink
The link at the very end of the K12OSN emails seems to be mis-pointed. Maybe it should be k12osn.org, not k12os.org?
_______________________________________________
Post by Barry R Cisna
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Roger Nutbeam
2014-04-08 17:43:03 UTC
Permalink
You'd definitely want to run your outside<-in connections over a VPN too. I
use OpenVPN and it works well.
Post by Les Mikesell
Post by Roger Nutbeam
Freenx is a lot better performing than X over wireless. I haven't had the
chance to test x2go but from what I've looked it so far, I like what I
see.
X2go uses some of the same nx libraries as freenx and unlike NX the
clients are also open source. At least on CentOS6 freenx and x2go
packages can co-exist if you want to try both, although they don't
interoperate. X2go seems to have more active development now and
seems pretty usable. I think a USB-boot into something that just
opened an x2go window might be a practical thin client - but I haven't
run a large number of clients against the same server. There is
probably some overhead for the virtual sceen/cache/compression for
each session.
--
Les Mikesell
_______________________________________________
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Les Mikesell
2014-04-08 17:52:37 UTC
Permalink
Post by Roger Nutbeam
You'd definitely want to run your outside<-in connections over a VPN too. I
use OpenVPN and it works well.
That's always a good idea - but both NX and x2go will use ssh for
their connection and tunnel everything through it anyway. X2go will
also transparently fire up a pass-through connection using rdp to a
windows desktop if you need remote access and want the
encryption/compression/caching features.
--
Les Mikesell
***@gmail.com
Roger Nutbeam
2014-04-08 18:06:36 UTC
Permalink
I know both will use ssh tunneling, but I find a VPN easier to manage on a
larger scale than ssh clients, keys and tunnels. It also doesn't give me
the warm fuzzies forwarding ssh through my firewall to internal machines.
Post by Roger Nutbeam
Post by Roger Nutbeam
You'd definitely want to run your outside<-in connections over a VPN
too. I
Post by Roger Nutbeam
use OpenVPN and it works well.
That's always a good idea - but both NX and x2go will use ssh for
their connection and tunnel everything through it anyway. X2go will
also transparently fire up a pass-through connection using rdp to a
windows desktop if you need remote access and want the
encryption/compression/caching features.
--
Les Mikesell
_______________________________________________
K12OSN mailing list
https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
Jim Kinney
2014-04-08 19:05:57 UTC
Permalink
Same encryption algorithms on ssh and openvpn. Ssh through VPN is bloated
and overkill for k12 needs. Can manage ssh keys with freeIPA on centos6 as
ssh knows through Pam to check LDAP for user keys (slick!). Big issue is
requiring password on ssh keys for users.
Post by Roger Nutbeam
I know both will use ssh tunneling, but I find a VPN easier to manage on a
larger scale than ssh clients, keys and tunnels. It also doesn't give me
the warm fuzzies forwarding ssh through my firewall to internal machines.
Post by Roger Nutbeam
Post by Roger Nutbeam
You'd definitely want to run your outside<-in connections over a VPN
too. I
Post by Roger Nutbeam
use OpenVPN and it works well.
That's always a good idea - but both NX and x2go will use ssh for
their connection and tunnel everything through it anyway. X2go will
also transparently fire up a pass-through connection using rdp to a
windows desktop if you need remote access and want the
encryption/compression/caching features.
--
Les Mikesell
_______________________________________________
K12OSN mailing list
https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>
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Roger Nutbeam
2014-04-08 19:41:22 UTC
Permalink
Well you can turn passwords off using ssh and just use the keys to
authenticate.

OpenSSH and OpenVPN use different ciphers. I don't think arcfour is even
listed as a cipher option for OpenVPN. The protocols are different too, so
you get different network behavior using them.

You could choose not to use ssh tunneling on your clients if you're using a
VPN, so that gets rid of the "messy". No point in an encrypted tunnel in an
encrypted tunnel. Unless of course one is clinically paranoid.

Of course using either ssh or a VPN is pretty secure as long as they're
well implemented.

I still don't like encrypted tunnels through my firewall that I can't
inspect.
Post by Jim Kinney
Same encryption algorithms on ssh and openvpn. Ssh through VPN is bloated
and overkill for k12 needs. Can manage ssh keys with freeIPA on centos6 as
ssh knows through Pam to check LDAP for user keys (slick!). Big issue is
requiring password on ssh keys for users.
Post by Roger Nutbeam
I know both will use ssh tunneling, but I find a VPN easier to manage on
a larger scale than ssh clients, keys and tunnels. It also doesn't give me
the warm fuzzies forwarding ssh through my firewall to internal machines.
Post by Roger Nutbeam
Post by Roger Nutbeam
You'd definitely want to run your outside<-in connections over a VPN
too. I
Post by Roger Nutbeam
use OpenVPN and it works well.
That's always a good idea - but both NX and x2go will use ssh for
their connection and tunnel everything through it anyway. X2go will
also transparently fire up a pass-through connection using rdp to a
windows desktop if you need remote access and want the
encryption/compression/caching features.
--
Les Mikesell
_______________________________________________
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For more info see <http://www.k12os.org>
_______________________________________________
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For more info see <http://www.k12os.org>
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