PDN Gateway Overview
Network Deployment(s) ▀
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
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This reference point provides tunneling and management between the S-GW and the P-GW, as defined in 3GPP TS
23.401 and TS 23.402. The S8 interface is an inter-PLMN reference point between the S-GW and the P-GW used
during roaming scenarios. The S5 interface is used between an S-GW and P-GW located within the same administrative
domain (non-roaming). It is used for S-GW relocation due to UE mobility and if the S-GW needs to connect to a non-
collocated P-GW for the required PDN connectivity.
Supported protocols
Transport Layer: UDP, TCP
Tunneling:
GTP: GTPv2-C (signaling channel), GTPv1-U (bearer channel)
PMIPv6: GRE or IP-in-IP
Network Layer: IPv4, IPv6
Data Link Layer: ARP
Physical Layer: Ethernet
S6b Interface
This reference point, between a P-GW and a 3GPP AAA server/proxy, is used for mobility-related authentication. It
may also be used to retrieve and request parameters related to mobility and to retrieve static QoS profiles for UEs (for
non-3GPP access) in the event that dynamic PCC is not supported.
From Release 12.2 onwards, the S6b interface has been enhanced to pass on the UE assigned IPv6 address (IPv6 prefix
and IPv6 interface ID) to the AAA server. S6b interface also has support for Framed-IPv6-Pool, Framed IP Pool, and
served party IP address AVPs based IP allocation. With this support, based on the Pool name and APN name received
from AAA server, the selection of a particular IP pool from the configuration is made for assigning the IP address.