Encryption, Compression in OpenAT


Hi All,
WIP-OpenAT connectivity contains the below mentioned Data compression techniques for GPRS.
WIP_BOPT_GPRS_DATACOMP -> Enable PDP data compression.
WIP_BOPT_GPRS_HEADERCOMP ->Enable PDP header compression.
I would like to know the what type of techniques are used in OpenAT WIP:3.00.06. I go through the document, but it is not mentioned in the document. I am also going to use Authentication encryption WIP-OpenAT contains PAP, CHAP, MSCHAP1, MSCHAP2 authentication techniques. Similarly i would like to know what type of Data - compression it is because once data is compressed on the otherhand (Server side)data should decompress. For this reasion i would like to know. And also what ment by PDP header, Basically we are using our own Data frame to transfer the data over GPRS. Please give me the solution for this.
I am using the
OpenAT OS: 4.20 Version
OpenAT WIP:3.00.06