Cisco Cisco Packet Data Interworking Function (PDIF)
Evolved Packet Data Gateway Engineering Rules
S2b Interface Rules ▀
ePDG Administration Guide, StarOS Release 17 ▄
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S2b Interface Rules
This section describes the engineering rules for the S2b interface for communications between the MAG (Mobility
Access Gateway) service residing on the ePDG and the LMA (Local Mobility Anchor) service residing on the P-GW.
Access Gateway) service residing on the ePDG and the LMA (Local Mobility Anchor) service residing on the P-GW.
MAG-to-LMA Rules
The following engineering rules apply to the S2b interface from the MAG service residing on the ePDG to the LMA
service residing on the P-GW:
service residing on the P-GW:
An S2b interface is created once the IP address of a logical interface is bound to a MAG service.
The logical interface(s) that will be used to facilitate the S2b interface(s) must be configured within the Egress
context.
MAG services must be configured within the Egress context.
MAG services must be associated with an ePDG service.
Depending on the services offered to the subscriber, the number of sessions facilitated by the S2b interface can
be limited.
Only the IPv6 transport mechanism is supported between the MAG service and the LMA service.
Node alive is not supported between the MAG service and the LMA service.
EGTP Service Rules
The following engineering rules apply to the S2b interface from the EGTP service residing on the ePDG:
First GTPU service is defined and then eGTP service is defined with association of previously defined GTPU
service and later on the eGTP service is associated with the ePDG service residing in same or different contex.
An S2b interface is created once the IP address of a logical interface is bound to a eGTP and GTPU service.
The eGTP and GTPU services must be configured within same egress context.
The eGTP service must be associated with an ePDG service.
no gtpc path-failure detection-policy
CLI must be configured under eGTP service to avoid path
failure detection action. When this configuration is used the ePDG does not cleans up session if the
retransmission timeout has happened for the echo request sent by ePDG.
retransmission timeout has happened for the echo request sent by ePDG.