The MS, the SGSN, and the GGSN can initiate The 'PDP context deactivation procedure'.

PDP Context Deactivation Procedure (MS initiated)

1. The MS sends 'Deactivate PDP context request' to the SGSN, including the TI of the PDP. There is an information element (IE) in this message, which is the 'Teardown Indication'. If this IE exist, this means all the PDPs associated with this APN/IP address should be deleted as well. If it is not exist, this means the PDP with this TI only need to be deleted.
2. Then, the SGSN sends 'Delete PDP context request' to the GGSN, including the NSAPI, the TEID. In addition to the Teardown Ind if it was sent from the MS.
3. After that, the GGSN returns 'Delete PDP context response'.
4. Now, the SGSN returns 'Deactivate PDP context accept' to the MS.
5. 'Radio access bearer release' occurs between the SGSN, the RNC, and the MS, in order to release the RAB.

PDP Context Deactivation Procedure (SGSN initiated)

1. The SGSN sends 'delete PDP context request' to the GGSN.
2. The GGSN returns ' delete PDP context response'
3. The SGSN sends 'delete PDP context request' to the MS.
4. The MS replies with 'Delete PDP context' accept.
5. 'Radio access bearer release' occurs between the MS, the RNC, and the SGSN.

PDP Context Deactivation Procedure (GGSN initiated)

1. The GGSN sends 'Delete PDP context request' to the SGSN.
2. The SGSN sends 'Deactivate PDP context request' to the MS.
3. The MS deactivates the PDP and reply with 'Deactivate PDP context accept'
4. the SGSN replies the GGSN with 'Delete PDP context response'.
5. 'Radio access bearer release' occurs between the MS, the RNC, and the SGSN.