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[Linrad] Re: Linrad MAP65 Communication II

Hi Rein,

> >> I started this with the intention to use 2 computers and drifted
> >> eventually towards this solution with one computer..
> >OK. But two computers should actually be easier since there 
> >would not be any timing issues.
> I have yet to have 2 computers to communicate.
No. The computers will not communicate. (bi-directional)
One computer sends UDP packets to an IP address that you have
to specify.

> The IP adress of the MAP65 laptop is obtained with the DOS
> Ipconfig/all and I can ping the addresses from the other computers.
Good. Together with what base port MAP65 is using that is all you 
need to know for Linrad.

> Also they work in the microsoft sense of the word, as a so called
> home network.
That is fine but not needed. If you can ping the addres that is
specified in Linrad, everything is fine. Then MAP65 can use
loopback at I think.

> >> Could not get the 2 computers to work together even after the
> >> introduction of the par_netsend_ip parameter.
> >Did you really write the address of the computer inside which 
> >you run MAP65 into the file?
> Absolutely and the correct IP address shows up in the networking
> setup menu ( ist or second line )
OK. Then the problem is in the network. Unfortunately I know nothing
at all about networking. I always disable all firewalls and other
difficult to manage safety features.

I hope someone else can help. I am sorry, but I just do not know.

> >Start at SM5BSZ Home Page:
> >http://www.sm5bsz.com/index.htm
> >http://nitehawk.com/sm5bsz/index.htm
> >http://g7rau.demon.co.uk/sm5bsz/index.htm
> Agreed and I had and have seen that, It's one of those things
> we talked about, I came from MAP65 and was expecting to see 
> something like use "unicast for ( 1 or 2 computers ) " You see
> I still do not get it!
I do not understand why you expect to see "unicast for ( 1 or 2 
computers )." 

I do not know much about networking. The code in Linrad is built
on prototype code that Roger, W3SZ supplied long ago. I built
on it by use of trial and error. The Linrad network is never
unicast however if I choose to believe what Wikipedia writes:
"Unicast messaging is used for all network processes where a 
private or unique resource is requested making most networking 
traffic Unicast in form. Unicast is used where two way connections 
are needed to complete the network transaction."

The Linrad -> MAP65 data stream is not a two way communication.
> You did not define what you understand uni ( one to one = 2 )
> or one to more than 2 ( multi ) 
No. I never used the word uni. As seen from within Linrad the
transmission of data is multicasting. Linrad does not know
whether there is anyone listening at all or whether many
computers are receiving the data. 

> Believe me Leif, I have been told by others that I have been e-mailing with,
> both settings to use. For the same situation.
Now you refer to settings in MAP65 and I do not have any
idea in what way they differ. I hope Joe is reading this and
can explain to us:-)

> There is confusion about this. It is not just me. I am trying to eliminate
> this, and get to instructions that gets one results right away,
Dear Rein, I have no idea what the problem might be. Maybe Joe
has coded MAP65 to listen to if unicast is specified and to or something else when multicast is specified.

The network in Linrad is uncomplicated. Typically one would select
a totally free IP address in an addres range that is not transmitted
to the outside world through the router connecting to the Internet.
There is a standard for that and that standard is adopted in Linrad.

Joe wanted something different to minimize the load on his network.
Linrad allows free experimentation - but I do not have the knowledge
about networking to give any advice. I am sorry for that.

> You will say almost I am not going to do this because I like to see how
> people make out and I learn from it.
I have tried to the best of my knowledge to tell you everything that
I know - and that is not much.

I do know however that as seen from Linrad networking is extremely simple.
Specify an IP address and a base port and Linrad will send data there
as specified in the network setup.

> I really am not out to make trouble. I hurts your cause! Isn't satisfying
> if people can download your work that you have put so many efforts towards,
> just out of the box? 
> Leif, I really want to be positive and creative here. Really.
I appreciate that - but I can not explain why Joe adopted the terminology
of uni- and multi-casting.

> >On this page there are two links
> >Linrad <http://www.sm5bsz.com/linuxdsp/linrad.htm>
> >Linrad for newcomers <http://www.sm5bsz.com/linuxdsp/usage/newco/newcomer.htm>
> >
> >The newcomer page has a link to <http://www.sm5bsz.com/linuxdsp/linrad.htm>
> >the same as the first link on the SM5BSZ Home Page.
> >The Linrad link goes to "Linrad Home Page" and here you should
> >search for network. The word network occurs two times on the page and
> >the second occurance is this:
> >LINRAD NETWORK <http://www.sm5bsz.com/linuxdsp/run/network.htm> 
> >
> >That page starts like this:
> >General
> >
> >Linrad uses the network to make raw or processed data available 
> >to other programs that may run on the same computer or on any 
> >other computer in a local network.
> >
> >Linrad can multicast on IP addresses (groups) to 
> > This means that several computers can multicast 
> >their data to the network simultaneously in different groups.
> >
> >The Linrad base port has to be set between 50000 and 65000 
> >in steps of 10 and Linrad will send data to a port with an 
> >offset with respect to the base port that depends on the 
> >data format. 
> > 
> >> The only place I saw the " _cast" parameter selectable is in MAP65.
> >Yes. The Linrad network was not intended for MAP65 originally 
> >but for use in a multioperator contest station. I got 
> >enquieries about the use of two computers on the same antenna. 
> >Would it be possible to connect Delta44 cards in parallel or 
> >would one need two RX2500 units. (The answer is perhaps. 
> >There could be a significant increase in the noise floor but 
> >a really thick and short wire between the two Delta44 might 
> >help.) The network was originally implemented as a solution
> >to this problem.
> OK Leif I get this and I fully understand that you would keep 
> the Linrad as flexible and adaptable to all possible applcations
> present and future. On the other hand one approach does not exclude
> the others.
> You just introduced the beginners version.
> Great step forward.
> May I say imagine if you had introduced this 5 or 
> perhaps even 10 years ago. Getting old, can't quite 
> remember if it is has been 10 years or more. The introduction of
> the windows version, has without a doubt, made it easier to do this.
> But I believe you could have done this mush earlier even in Linux.
It is not so easy. I did not have the knowledge to do it earlier.
I find it extremely difficult to follow the way others think.
It is very hard to know what to write in order to meet unspoken
assumptions that occur in the amateur community. The current
example with uni/multi is typical. I did not have the slightest
idea that a problem was hidden here before you brought it up.
Now I know it will be a good idea to write some more about
what Linrad is doing. Maybe I should just remove all occurances
of the word cast. Linrad sends UDP... 

> Let me suggest not to use "N" for this, as "N" is used for network setup
> already any other not used letter would be fine I think 
There are no not used letters. Many letters occur many times 
and each time the user is presented with a choice it is necessary
to read the text and take the decision based on what it says.

> I was using ver 3.06 hat has the "N" option and I for get how I got
> to the Network setup but i did. 
If you are a newcomer there is no network. Not many other things
either, just a basic receiver.

> With a selection as the "N"ewcomer you can of course go to another
> version of the existing program.
I do not understand what you mean here.
> Linux is out of the box these days as long as one stays away from sound
> cards andthe like and want to do programming plus a few other things I
> guess.  
The most popular distro seems to be Ubuntu. I personally find that
one rather difficult because of all its safety features. I find Debian

> The use of Linrad with MAP65 is at this point a much more important 
> application in amateur cicles I think. There is ton of amateurs on
> 2 M EME with JT65 these days, virtually around the clock 7 * 24 * 30/(31)
> They all could use Linrad/MAP and the way people spend effort
> ( and money ) these days many try to obtain the very best within there means.
> The nature of EME in a 100 Khz wide band makes finding each other 
> a difficult problem and time consuming problem , it ties in with the 
> hated use of the EME loggers etc etc.
> MAP65 allows to operate without help from loggers, sked lists, the phone.
> you name it.
Yes. I have no idea why there is a problem in the first place. I find
it hard to believe it is within Linrad or its setup procedures.

It could be the operating system: Visual effects, firewalls, other
softwares that destroy the latency, whatever. 

It could be the network itself. Routers, switches, whatever.

It could also be MAP65. 

> My  latest results are now as follows. 
> All machines XP
> Having a laptop      P4 1.7 GHz 512 MB 
>        2 benchtops   P4 1.7 or 1.9 Ghz 512 NB and the 2d 1024 MB memory
> Loaded this morning fresh MAP65 I-Q linrad,2.35  is included in the MMAP65
> package,available from K1JT's web pages ( google MAP65 Linrad will gets one there )

> Installing this has become second nature here and it really is out of the box.
> It needs of course a RF SPACE SDR NN and USB port(s) on the computer to be
> used.
> The 512 MB machine runs fine with MAp65, there  are no interruptions of the MAP65
> data stream reception when the WSJT65B send cycle starts. Linrad keeps on sending
> data it seems and as said it is working. Except for a minor point.
> It I open a pull down menu in MAP65 the data steam reception of MAP65 stops
> as in the previous laptop version when MAP goes in "send"
Visual Effects may cause such problems.

> So the pulling down of the a menu causes an event that prevents linrad
> sending out data, I think that is really what is happening.
> similar as with the laptop. I can live with that I think
I have a laptop with XP and a 2.8 GHz Pentium 4. The system monitor
shows 100% CPU load for about 5 seconds just before transmit
starts, but that has no adverse effects at all. Linrad and MAP65
are excactly as they come with Joes package except for the change
needed to use SDR-14 instead of SDR-IQ.

If I move a window while the CPU load is 100% the 100% load lasts 
for 10 seconds but that does not affect the processing at all. 
That is with all visual effects enabled. When I disable visual
effects I see no increase in CPU load while moving windows around.

> The 2d benchtop is just working! During send Linrad keeps working and 
> sending audio to the sound card. it keeps doing this even when MAP65
> goes into send. WSJT tones and receiver audio are both present.
> Sound card gets obvious signal from 2 sources. Ansd it is not causing
> any problems.
OK. I do not know much about all the softwares that typically
run in the background under XP. Having both Linrad and MAP65 on
a single computer is time critical and unforgiving because of
the way USB behaves. The problem does not exist under Linux....

> Out of perhaps as many as 15 loadings with the laptop I had that happen
> once! This indicates that there is something time critical on the edge.
> It is by no means clear to me what interaction there is between
> Linrad and MAP65 except that they both use the same CPU and of course
> any high load of the CPU could cause trouble.
The problem is the drive routine for the USB. The fact that it crashes
rather than looses some data (with an appropriate error code) when
it is not serviced in time. Linrad itself is not sensitive to
high CPU load and there is no interaction between Linrad and MAP65
except for Linrad sending (blindly) UDP packages while MAP65
looks for them.

> MAP65 does not seem to care whether the incoming data stream stops as
> in the Linrad "P" key stroke . as soon the data steam resumes ( 'B")
> it accepts the data
> Linrad on the other hand seem to show sensitivity to "events" and
> it does not recover though it keeps running in some fashion.
Yes. As I repeatedly tell you: I do not know how to handle a crashed
device driver under Windows so Linrad can not do anything. I am not 
sure it can be done at all. The thread is hanging on a blocking
read and I have no idea what to do to force a return.

> Certainly if the the CPU gets to busy trouble start. 
Not really. With other hardware as well as under Linux CPU
overload does not cause crashes, only loss of data which
is not a big problem. If the output stutters a little
while one resizes a window or opens another program is
no problem. Not even if one wants to hear what is being received
while it happens. Usually the only consequence would be a
couple of missed screen updates.

> However, I have a 15 MB powerpoint picture fileel of my beloved
> harbor of Rotterdam and I can kick this file from one computer
> to the other on this very network we are taking about, via  the
> 2 network cards in these 2 computer faster than I can see it happen. 
> Msecs probably. Have this had working here since I started this 10
> days ago.
OK. The hardware is fine. 

> >> It is hard for me to imagine that he is able and to get away with
> >> this in a corporate environment with out REALLY understanding
> >> networking. Or, more likely that he is the corporate top IT person
> >> himself!
> >It is not complicated at all. I think you have been confused
> >by far too much information....
> I thought at that point that corprate IT management do not want computer
> users to do this stuff, and it is unlikely in my experience, that users
> in the corporation have root privileges. I am not sure what it takes
> to work with IP addresses in XP or Vista.
I think this sentence contains the root of the problem.

It takes nothing to work with IP addresses in XP or Linux and I do
not think Vista or Windows 7 would be different.

A program running inside a computer can send UDP packages to any
IP address. No privileges needed and it does not matter what IP
address the computer has. The corprate IT management assigns an
IP address to your computer but that is no limitation to where
you can send UDP packages. The corprate IT management will however
not allow arbitrary IP addresses through the routers. What Mart
did was to send UDP to an IP address that is legal and will be
routed to him. Any other computer that is along the path 
can also pick up the data as far as I understand. The IP address
does not have to be the address of the computer itself. Any
computer can receive all the data that is seen at the input
of the network interface.

> >> Next question
> >> 
> >> Once MAP65 goes into transmit ( generating
> >> tones via the sound card ( selected in MAP65 )
> >> and also selected earlier for Linrad ( by Joe's
> >> parameter file set.)
> >> 
> >> Should at that point the USB data stream form the
> >> SDR I-Q box into linrad stop or not?
> >The USB data stream should not stop. Linrad does not
> >know that MAP65 is listening. 
> Very true, I see that now on the 2 working machines.
> >
> >> The incoming data are useless at that point anyway.
> >Hmmm, you can use it to see if you are transmitting
> >at the desired frequency and you can use Linrad to monitor
> >your frequency drift. You could also connect your receiver
> >to a directional coupler during transmit and use the
> >Linrad S-meter to check your WSVR. 
>   I would think in the sense that it would take a lot of 
>   T/R swiching, attenuation to make it useful. If implement
>   yes, linrad is a selective voltmeter, power meter or
>   spectrum analyzer in the end. 
It is actually quite easy. Standard is to switch the preamp to 
a dummy load during transmit. You might switch it to a 60 dB 
attenuator instead. On the other side of the attenuator a single 
relay can switch between forward or reverse on a 30 dB directional 
coupler. Safe and sound:-)

> >> Should at the end of the send period in MAP65 the
> >> USB data stream resume?
> >NO. USB should run all the time.
>    It does on the working machines. Is MAP65 collecting
>    streaned data a this point? 
I have no idea. 

> >> Suppose I did away with the USB SDR I-Q all togheter,
> >> 
> >> And change back to the delta44 what should happen
> >> then in this respect ( linrad keeps working during the
> >> send period? I have removed the USB factor now?
> >That should solve the problem. You could also connect
> >a second computer for MAP65.
>    Here is the network problem again popping up.
>    Linrad is streaming data on the network card
>    with the right IP ( prove of this is that I can
>    transfer files form the linrad "shared" documents 
>    directory ( windows security stuff ) to the
>    "shared" documents directory on the MAP65 computer.
I have no idea whether Windows security stuff will allow the
ports used by Linrad. I also do not know if UDP is handled
differently from other protocols.

>    Windows lets one set up a shared directory for John 
>    at Larse's computer as well as a shared directory
>    for Bjorn at Larse's computer, John can not send
>    data to Larse's computer except to his dedicated
>    shared directory and so on.
>    That's why I keep on asking about Shared
Well, I have no knowledge at all about these things. I do not think
it is related to the Linrad -> MAP65 problem. I do not think
the protection of disk access from different users is related in
any way to how a firewall blocks data.

>   I do not understand why I can't get with the data stream clearly 
>   present, into MAP65. It HAS to be a network problem or setting. 
>   The one computer system is working, the only difference is 
> vs on another ( protected ? )
>   computer.
>    While writing this I realize all of the sudden that the laptop
>    has a firewall! ( new in XP I think vis XP updates ) 
>   On the other hand if this is the reason I would have expected 
>   plenty of questions by other windows users here on the
>   reflector "Do have a fire wall on the laptop " 
>   Just think here on paper.
>   Will check this later, just one click to turn that off.
I suggest you turn it off at both ends for a test.
This was written by HB9DRI on the list 08/08/17:

Subject: Linrad + MAP65 "How to ...Guide"
STEP 1) Connect your computers into your network and check communication in
both directions, disable windows firewall or create and exception rule into
the firewall, because my network is behind a Firewall I disable the windows
firewall to avoid problems. The MAP65 need to have a static IP address
otherwise you will need to change in the setup of Linrad when the IP address
of the MAP65 host change, prefer use static IP's for both computers.

>   I have genuine XP stuff here on these machines and MS will check
>   it all the time. With the drive to fight cyberwars etc, they make a
>   big efforts to update the OS with security fixes ( almost daily
>   via internet updating ) One of these updates is the firewall thing
>   some time ago. I know the laptop has it. 
There should be plenty of people who know these things.....

> >> Going to put MAP65 I/Q on 3 other XP bench tops
> >> and see what happens in transmit.
> >You mean Linrad + MAP65-IQ ?
>   Yes in a way, Joe has made Linrad3.05 part of the 
>   MAP65 I-Q installation.
>   If one installs MAP65 I-Q linrad is also installed both
>   with short cuts.
>   Ready to go, as on my 2d and 3d computer.,
Yes. I just tested it on the 2.8 GHz P4:-)

> >> In conlusion, I get the impression of being an idiot having
> >> to ask all these questions in the presence of 150 other
> >> users!
> >It does help:-)
> >Your questions have lead to one improvement in the Linrad setup
> >dialogue already. Hopefully there will be someone who will 
> >help by writing a suitable introduction to networking for
> >Linrad users to be placed on the Linrad network page....
> Leif, I have a paper here from an user that should fit as a link on
> your web page. I have suggested him to contact you. I think every- 
> thing is in the paper and there would be no need for me to do it.
> Although I am still willing to do it.
> The point is also that I did not learn anything new from his text, had
> done every thing right from the beginning. He has a way of creating
> the par_netsend_ip file by starting from a copy of one of the other
> parameter files and than modifying it. I have the strong impression
> from my doings here that that is not needed, do not know really.
This particular trick could be a workaround for the standard settings
of too complicated editors that are difficult to force to produce plain
ascii text files. By loading a plain text file you tell your editor
what type of format (no format at all) to save.

> Also next week I will try to clean up the 25 or so files we generated and
> edit it to a Q&A format. This  should make the reading easier.
> Next week I will also comment on all your other comments in this message.
> I am running out of time here.
> As nobody else seem to have the problems I have here I would love to give
> you a hand with a possible solution.
I suspect others have had the problem silently. No way of knowing really....

> What keeps me from doing this is really to get a "development" or just
> "test", if you like,  machine together. A few years ago I compiled linux
> versions of Linrad, but found it difficult to get everythig linux
> installed so that I could compile and go through the process without
> generating pages with error messages due to missing stuff in the Linux 
> installation on the drive. 
> I imagine that working in Windows is even more trouble as Bill wants
> me to buy the, the MS development software.
Linrad is old-fashioned. You can develop code under Windows as easy as
under Linux. It is actually more difficult to install Windows than to
install Linux on unknown computers that one can recover these days.
A Pentium 3 is fast enough but hard to get running under Windows.
Under Linux the installation of all the drive routines is automatic

> Perhaps you can make me suggestions what to do for this if anythisng
To do for what? Presumably you will find that the two computer
solution works perfectly when needless protection is turned off.
(Or configured properly.)

> The SDR hardware is not mine and it would be too much problems to send
> it over anyway, I am aftraid.
It would be pointless. Nothing that you ask about is related to
the SDR hardware. It is a pity that there is no searchable data base 
for old mails on this list. Alex wrote exactly what you want to know
one year ago only. The only way to find it (that I know of) is to
list the topics and look for what seems to be relevant.


  Leif / SM5BSZ

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