PPP Clarification


I have a question about the PPP session established with the command:ATD99**1#. Is the resuting PPP session between my external serial device and the Wavecom processor? Or is the session between me and my service provider?

I was under the impression that the session was just a data link to the modem, while a packet protocol was used between the modem and the network.

Thank you,


The session is open between the Wireless CPU and your service provider. When you connect to the APN of your service provider you receive PPP frames that should be displayed on your terminal after receiving CONNECT message.


Thank you for the reply chk.

I do see the PPP data, if I attach a terminal to the module. However, normally I have a microprocessor that manages the PPP session.

I did not specify earlier, but I define my PDP context as follows:


My understanding is that “PPP” is an alternative for the “IP” context specified. That is why I was thinking the PPP was only for the link from my processor to the Wavecom processor.

I would appreciate any further insight available on this.

Thank you,


My understanding is that the PDP-type here specifies how you want the GGSN to connect to the external network;
As far as Wavecom products are concerned, the interface at the modem is always carried over PPP.

Take a look at GSM 07.60, and see what you think…



Thank you for the reference link.

I think it is confirming my suspicion, that I am communicating to an end-point in the modem.

With that being the case, I do not need to be concerned with differences in PPP end-points, unless I switch to a newer modem firmware revision.

This also seems to match the byte counts from the carrier bill. I am guessing that if PPP to the GGSN was selected, we would be charged for the PPP initialization, framing, etc. bytes from our carrier.

Thank you,