Cisco ASR 5000 series Product Overview page 415

HRPD Serving Gateway Overview
Figure 110. PDN Connection Release by the UE Call Flow
UE eAN/ePCF
PPP VSNCP-Term-Req
2
PPP VSNCP-Term-Ack
Table 60. PDN Connection Release by the UE 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.
2 The UE decides to disconnect from the PDN and sends a PPP VSNCP-Term-Req with PDNID=x.
3 The HSGW starts disconnecting the PDN connection and sends a PPP-VSNCP-Term-Ack to the UE (also with PDNID=x).
4 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, ATT=HRPD, HNP. The PBU Deregistration message should contain all the mobility
options that were present in the initial PBU that created the binding.
5 The P-GW looks up the Binding Cache Entry (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).
6 The HSGW optionally sends a Router Advertisement (RA) with assigned HNP and prefix lifetime=0.
OL-22938-02
HSGW (MAG)
Attached
1
3
RA
6
P-GW (LMA)
PBU
4
PBA
5
Call/Session Procedure Flows ▀
Cisco ASR 5000 Series Product Overview ▄