Ppp connection


#1

Hi,
with fastrack supreme:

  1. is possible to connect a pc with fastrack using ppp even if there is no sim ?
  2. have/implement a socket listener on the fastrack that gets data from a client on pc ?
  3. execute a voice call and play a voice stream on answer after data are received ?

those are key questions for let my company decide if fastrack is a good solution for our product.
thanks


#2

You shouldn’t rellay be relying upon internet foums for your critical product decisions!

You should be engaging with your local Wavecom representative, who will be able to consider all the options in detail - under NDA if necessary…

However:

Why would you want to do that :question: :open_mouth:
Yes, that would be possible; but it would just give you a local link between the PC and the Fastrack - you would have no connectivity beyond the fastrack

Yes.

Not without a SIM.


#3

thanks for the answer.
of course we will contact wavecom, but the question is if wavecom have a good community for to solve problems.
Our experience says that if there is a collaborative community the efficience raise… :wink:
1)
I specified without sim because I tried to run a ppp connection with the modem for test without success.
I downloaded the socket server on uart1 then executed with wopen=1, but no ppp connection available.
if I try to check with at commands the status of wip plugin I get:
AT+WIPCFG=1
error
AT+WIPCFG=3
error
AT+WCFM=5
+WCFM: 00000471,0
3)
yes of course with the sim :laughing:


#4

i take you downloaded the wipsoft program into the modem before you tried those commands?


#5

thanks Madouc,

no I don’t have downloaded wpisoft, it was under samples folder and I thinked it is a sample like the others … :blush:
now I see it will register at commands for WIP : I will try it asap!
Now the question is, it will help for the ppp connection too?

thanks again!


#6

im not sure i inderstand your use of this ‘ppp connection’
to my understanding, you make a ppp connection to a server on the internet. the modem is purely a device in between.
(yes, you can make ppp connections using a wavecom modem, but for that the modem needs to connect to the network, so you will need a sim-card for that)
i don’t think you can make a ppp connection to a (any) modem, only to a server

(but then again, maybe i don’t understand ppp well enough)


#7

But a Wavecom modem is not just “any” modem!
Open-AT gives you the ability to have an application running within the modem - so you could establish a PPP connection between that application and a PC over the modem’s UART.

But, as I said initially, that would just be between the modem itself and the PC; without a SIM, as you say, there is no way to have any GSM connectivity at all - so there is no way to reach “beyond” the modem itself.

WIPSoft wasn’t mentioned initially; I don’t think you’d be able to do this with WIPSoft - you would need to write the application with WIPLib.

I suspect that this is all just a red herring; I suspect that the real question is, “Can I have a GSM/GPRS connection without a SIM” - to which the answer is an emphatic No!
The SIM is fundamental; it is your key to GSM Services. Without a SIM, you no access to any GSM services (inlcuding GPRS) at all (other than emergency calls). No amount of software trickery in the mobile can get around this - the network will simply not allow it.

Without a SIM, the modem effectively stops being a “Wireless Microprocessor” and just becomes a very expensive “Microprocessor”… :wink:


#8

wait wait…
is clear that I have no gsm/gprs connection without a sim :laughing:
I specified that I will make a ppp connection without a sim, only because I will test the tcp connection between the pc and the wavecom box without to have an gprs connection active. But actually I’m not able to make the ppp connection and my doubt was that the sim or a gprs connection is mandatory.
I have seen a little doc (in openatlua doc) on how create a ppp connection, I followed this doc but without success, Is not clear (for me :unamused: ) if there is a software to download or a switch for activate the ppp feature.

My target is to send a generated voice stream from pc to the wavecom box (the only way I think is with a tcp stream) then make a voice call and play the stream after the answer.
Is my target reachable?


#9

No, it is not the only way!

You could use any data transfer protocol that operates over a UART link - that obviously includes PPP, but is certainly not limited to PPP alone

Very probably.


#10

good to hear :slight_smile:

I would prefer tcp over ppp because is the protocol that I use more often and is simple, of course if I cannot find a solution for my ppp connection, will try for a raw protocol.


#11

Why do you say that?

Any protocol should seem easy to use on a system where it’s already implemented & installed - eg, a PC.

But when it comes to actually implementing the protocol yourself on a small, embedded system - such as a modem - you realise that there’s a great deal of effort that goes into making it appear “simple”

A library such as WIP takes a great deal of the labour out of it for you - but there is still a lot for you to do to build it into a usable application

Maybe this is something you should be outsourcing to a specialist?

Again, you really should be talking to your Distributor about this - there is far too much to cover in just a few forum posts!


#12

I say simple because :
the protocol is already implemented
is compatible with any client uses a tcp socket (available on most programming languages)
no needs to have additional knowledge (at least on the client side)
error handling already implemented in the stack

oh…
At the moment I realize that the doc haves some holes, it is function centric and not use case centric, there is no doc (or at least I have not found) that follow the flow of the developing an at project.
I hope those holes can be covered from my distributor (contacted yesterday).

We have ~50 developers (java,c++,c,asm,…), if for a small application like the one we will implement, we need to outsource it, then I think fastrack box is not what we need. We can buy directly a box that already implements this function, at the end is cheaper.
We found in the fastrack the flexiblity of a programmable box, but if this box can be programmed only from wavecom… you see… the flexiblity is gone.

For sure I missed something, and is my failure but, no one can answer on the ppp connection problem: we have tested it on 3 pc with same failure.
I can only think one of the below:
no one have used the ppp connection only between pc and uart1
the ppp connection only between pc and uart1 needs special configuration never covered (or hidden) in the doc
the ppp connection only between pc and uart1 is not possible

sorry I’m little frustrated :laughing:

anyway, will see if our distributor will give us the right hint :wink:


#13

Yes, that is very true! :angry:

See: viewtopic.php?f=3&t=1082&p=3863&hilit=particularly+poor#p3863

I agree - see: viewtopic.php?f=53&t=3573&p=13668&hilit=particularly+poor#p13668 :angry:

Yes, that is their job - they really should have been your first call!

But are they embedded firmware developers?

Embedded development - especially for small embedded systems like this - really is a specialism quite different from PC and similar application development.
Not least because you are working very much closer to the “bare metal” - and have to do yourself many (most?) of the things that you take for granted on a “big” system like a PC.
TCP/IP stacks being a case in point… 8)

Quite possibly.
There are, indeed, boxes out there with a complete UNIX implementation on board - the purchase price is higher, but that might be recovered in reduced development time…

Indeed it is; but it needs to be looked at as a comparable to a microcontroller, rather than an embedded UNIX box.
So you need to approach this with the mindset (and skill-set) of a microcontroller developer…

Not at all - see above.

That could be quite possible - apart from pure academic interest, I can’t really think of any reason to do that!

It has been noted elsewhere that setting up a PPP connection over a direct serial link in Windows is an extremely cumbersome and frustrating operation; eg, IIRC, it requires setting the COM port speed in at least 3 different places! :open_mouth:

Also possible - although it could be arguable about whether this is a failing in the Wavecom documentation, or in Microsoft’s documentation…


#14

Hello diste,
IMHO AarLogic C10/3 module from roundsolutions can be the way for you. This GSM module runs linux. It is more expensive than wavecom, but you can ssh or telnet in to the module and code in perl/python/whatever and use full power of open source community.


#15

Hiya,

As the Fastrack modem is shipped, you can make a PPP connection THROUGH the modem to an ISP - but you WILL require network connectivity (i.e. SIM card fitted to modem and account enabled for GPRS Data).

If you want to be able to connect TO the modem, you are going to have write (or have somebody write for you) an OpenAT application that is executed on the modem. Wavecom provide an additional Internet Library (WIP) to make this easier (i.e. you don’t have to write your own TCP/IP stack). By default the modem is simply a modem - it handles AT commands on the Serial (or USB) Port and is essentially transparent once a connection is made.

The advantage of the Wavecom Modems is that Wavecom provide an API called OpenAT that enables you to embed custom applications onto the Modem (like any other embedded microcontroller), and have all the facilities of the modem ‘there’ - thus cutting down on the number of devices required in your project.

Be warned - writing applications for OpenAT is probably going to be unlike coding for any other processor you have ever used.

You may want to look into using Lua on the Wavecom Modem for your initial testing and development. Lua uses a PPP/TCP connection via the Serial Port, and lets you create TCP/IP enabled applications quickly. That said, I personally haven’t used it as I’m more comfortable programming in C and working close to the hardware.

ciao, Dave


#16

but that would still require you to go through the grief of setting-up a PPP direct serial cable connection on Windows… :frowning:


#17

aha, ok only “SIM card fitted to modem and account enabled for GPRS Data” or activate the gprs dial connection too? It is important because I do not will create a gprs connection.

with lua ppp connection works perfectly! It can be the solution if I find the way to play the audio stream through lua (adl_audioStreamPlay).

thanks, I will evaluate it if I fail with fastrack.

anyway … great step ahead! Thanks


#18

Hiya,

Simplisticly:

GPRS is a radio mechanism that just moves packets of data between two points.
PPP is a method of transporting TCP/IP packet data between two devices via a serial link (ANY serial link - CSD, GPRS, RS232, SSH etc)
TCP/IP is a network protocol for moving data between two network nodes.
HTTP/FTP/SSH etc are application protocols that describe how the data inside a TCP/IP packet is formatted.

Just to confirm: PPP is a TCP/IP transport mechanism (in the same way that Ethernet is a TCP transport mechanism). PPP on it’s own won’t do much for you - you will need to connect to a PPP server to create a TCP/IP link. The ISP usually provides a PPP server for users to connect to, as do Telco’s that provide data services.

A GPRS connection CANNOT be established between the modem and the ISP/Telco without having a SIM card present (and probably the phone account has to be explicitly enabled for GPRS data) - in the same manner that you cannot make an ordinary phone call without having a SIM card present.

By default, the Wavecom Modems do not run ANY internal servers - they behave strictly as amodems (i.e. take commands from serial port, make connections and pass data between connections). However, you can use OpenAT to create you own application that will behave as a server to do pretty much watever you desire. LUA is an example of such an application, as is WIPSoft.

With LUA you are probably connecting to the modem using a PPP link over RS232 (or USB). LUA provides the PPP server, as well as the application level protocols such as TELNET and FTP.

Hope this helps a little.

ciao, Dave


#19

thanks dave,
you help me in all my questions like a tutor :smiley: I appreciate it,

I played with lua-w and I find it a nice tool, now I should decide if is better implement sound apis in lua or make a custom application in the usual way.

I found something strange in the example (tcp server): if you define in appli.c OVER_UART_PPP_SERV the ppp server go up and then shortly exits, makes 3 tries and then the app exits.
If you move calls explicitely in the main appli_entry_point(); shortly before to call cfg_uart_ppp_serv( appli_entry_point); it works.

I solved the problem, I’m still curious how should be the right code …

P.S.
for the forum moderator: In other forums is usual to change the subject with prefix [SOLVED] when is the case. Is valid here too?
I think it helps a lot the users.


#20

Well of course… … You can change the subject line whnever the need arises… There is an “EDIT” option above the post( which you give ) and you can easily change the subject line using it…

Hope it helps… :smiley:
Regards,
Paruthiv