Cisco Cisco Packet Data Gateway (PDG)
Logical Network Interfaces
Table 1: Logical Network Interfaces on the ePDG
Description
Interface
The secure interface to the WLAN UEs in the untrusted non-3GPP IP access network,
the SWu interface carries IPSec tunnels. The ePDG uses IKEv2 signaling to establish
IPSec tunnels between the UEs and the ePDG. It also supports the negotiation of
configuration attributes such as IP address, DNS, and P-CSCF in the CP
(Configuration Parameters) payload of IKE_AUTH Request and Response messages.
the SWu interface carries IPSec tunnels. The ePDG uses IKEv2 signaling to establish
IPSec tunnels between the UEs and the ePDG. It also supports the negotiation of
configuration attributes such as IP address, DNS, and P-CSCF in the CP
(Configuration Parameters) payload of IKE_AUTH Request and Response messages.
SWu Interface
The interface to the 3GPP Diameter AAA server, the SWm interface is used for
WLAN UE authentication. It supports the transport of mobility parameters, tunnel
authentication, and authorization data. The EAP-AKA (Extensible Authentication
Protocol - Authentication and Key Agreement) method is used for authenticating
the WLAN UEs over this interface. SWm interface supports both TCP and SCTP
protocols.
WLAN UE authentication. It supports the transport of mobility parameters, tunnel
authentication, and authorization data. The EAP-AKA (Extensible Authentication
Protocol - Authentication and Key Agreement) method is used for authenticating
the WLAN UEs over this interface. SWm interface supports both TCP and SCTP
protocols.
SWm Diameter
Interface
Interface
The interface to the P-GW, the S2b interface runs PMIPv6 (Proxy Mobile IP version
6)/GTPv2 protocol to establish WLAN UE sessions with the P-GW. It also supports
the transport of P-CSCF attributes and DNS attributes in PBU (Proxy-MIP Binding
Update)/Create Session Request and PBA (Proxy-MIP Binding
Acknowledgement)/Create Session Response messages as part of the P-CSCF
discovery performed by the WLAN UEs.
6)/GTPv2 protocol to establish WLAN UE sessions with the P-GW. It also supports
the transport of P-CSCF attributes and DNS attributes in PBU (Proxy-MIP Binding
Update)/Create Session Request and PBA (Proxy-MIP Binding
Acknowledgement)/Create Session Response messages as part of the P-CSCF
discovery performed by the WLAN UEs.
S2b Interface
Transport Combinations
Table 2: Transport Combinations for the ePDG
Combination Supported
for Deployment?
for Deployment?
GTPv2
IPSec Tunnels (between
the WLAN UEs and the
ePDG)
the WLAN UEs and the
ePDG)
IP Address Allocated by
the P-GW for the WLAN
UEs
the P-GW for the WLAN
UEs
Yes
IPv4
IPv4
IPv4
Yes
IPv6
IPv6
IPv4
Yes
IPv4
IPv6
IPv4
Yes
IPv6
IPv4
IPv4
Yes
IPv4
IPv4
IPv6
Yes
IPv6
IPv6
IPv6
ePDG Administration Guide, StarOS Release 19
5
Evolved Packet Data Gateway Overview
Logical Network Interfaces