PDN Gateway Overview
Step
Description
4
The UE acknowledges the receipt of the request with a VSNCP-Term-Ack (PDNID=x).
5
The HSGW begins the tear down of the PMIP session by sending a PBU Deregistration to the P-GW with the following
attributes: Lifetime=0, MNID, APN, HNP. The PBU Deregistration message should contain all the mobility options that
were present in the initial PBU that created the binding.
6
The P-GW looks up the BCE based on the HNP, deletes the binding, and responds to the HSGW with a Deregistration PBA
with the same attributes (Lifetime=0, MNID, APN, ATT=HRPD, HNP).
7
The HSGW optionally sends a Router Advertisement (RA) with assigned HNP and prefix lifetime=0.
PDN Connection Release Initiated by P-GW
This section describes the procedure of a session release by the P-GW.
Figure 13.
Table 6. PDN Connection Release by the P-GW Call Flow Description
Step
Description
1
The UE is attached to the EPC and has a PDN connection with the P-GW for PDN-ID=x and APN with assigned HNP.
PDN Connection Release by the P-GW Call Flow
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
How the PDN Gateway Works ▀
93