Is PPP stack necessary?


#1

hello!

I’m developing a systerm with Q24PL002 with OS 657e and WIP 3.10.1030

I use Q24PL to access GPRS network, connect with another Q24PL and exchange data.
The transmit(receive) data come from(go back to) an extern embedded systerm. The Q24PL just like a modem.
I saw the wavecom document. it seems that exchange data between the GPRS modem and the PC or extern systerm like mine should via PPP stack.

My question is if I must use PPP, or it has some other way?(I want my extern embedded systerm as simple as possible and don’t contain too many stacks.)
How can I do it?

Please help me.


#2

Hi,

I myself have been trying to answer this question, almost all of the available documentation suggests that a PPP stack is required, infact if you do ‘ATD99**1#’ your GPRS device will start to recive PPP frames.

However 99% of embedded devices dont have PPP stack already, so it would be a very odd decision to require all devices to be updated with a PPP stack.

I pose an open question to the forum, is there a ‘transparent’ or ‘compatability’ mode, that allows RS232 data to be sent to the GPRS device, then the GPRS device wrap that so it can be transmitted ?

Matthew J Fletcher
Serck Controls Ltd


#3

there’s an IP packet manipulation API planned in WIP5, although I think it was primarily intended for tunnelling and firewall-like applications. There might be enough here to let you implement tranparent RS323<->IP tunnelling. Check the doc and/or your distributor for details.

Check also the GPRS APIs in ADL: since you aren’t using the WIP IP stack, ADL might offer what you need.

Of course, that means in both cases that you’ll have to develop an Open AT application.


#4

there’s an IP packet manipulation API planned in WIP5, although I think it was primarily intended for tunnelling and firewall-like applications. There might be >enough here to let you implement tranparent RS323<->IP tunnelling. Check the doc and/or your distributor for details.

Check also the GPRS APIs in ADL: since you aren’t using the WIP IP stack, ADL might offer what you need.

Thanks for the information.

Could you point me to the GPRS APIs in ADL, is it available as an Application note from the developer area, or is it part of the Open AT development kit ?

Of course, that means in both cases that you’ll have to develop an Open AT application.

Indeed, and maintain it for years to come across diffrent software versions, and be tied into Wavecom chipsets for my application.

Matthew J Fletcher
Serck Controls Ltd


#5

It is, it’s the default user API in C, and its doc is in the SDK.

That’s true. If you develop software you have to maintain it, so if part of it runs on the modem, then part of the maintenance will happen in the modem.

As for the lock-in:

  • either there’s a standard way to do raw RS232<->GPRS tunneling: then go with one of the many chipset providers implementing it! (I personally don’t know anything about such an hypothetical standard, but I never looked for related info and I’m not knowledgeable at all in this domain);
  • or there isn’t, and then whatever ad-hoc solution you’ll pick, you’ll be locked to a unique chip maker no matter what.