Connection to GGSN & PDP Context Type

Hi All,

We are using the Q2687 modem to access the GPRS network. My question relates to establishment of a PDP context and the resultant underlying protocol topology instantiated.

We attach to the GPRS network;
We establish a PDP context AT+CGDCONT=1,”IP”……
If we are connecting to a GGSN that supports PPP PDP context as well as IP can we use AT+CGDCONT=1,”PPP”… instead? Does the Wavecom modem support this?
If we stick with an IP context (AT+CGDCONT=1,”IP”) will this be an IP connection or a PPP connection to the GGSN?

I cannot see anyone using “PPP” context type so I am curious to understand its use / limitation and also to get a better handle on the GPRS networking protocols when we establish the PDP context.

If you could help here (and I am more than happy to read any documents you can pass across) that would be great.

Regards

Andy