Cisco Cisco Packet Data Gateway (PDG)
Evolved Packet Data Gateway Overview
Network Deployment(s) and Interfaces ▀
ePDG Administration Guide, StarOS Release 17 ▄
15
Logical Network Interfaces
The following table provides descriptions of the logical network interfaces supported by the ePDG in the E-
UTRAN/EPC network.
UTRAN/EPC network.
Table 1. Logical Network Interfaces on the ePDG
Interface
Description
SWu
Interface
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.
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.
SWm
Diameter
Interface
Diameter
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.
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.
S2b
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.
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.
Transport Combinations
The table below lists the IPv4/IPv6 transport combinations for the ePDG and whether each combination is supported for
deployment in this release.
deployment in this release.
Table 2. Transport Combinations for the ePDG
IP Address Allocated by the P-GW for the
WLAN UEs
WLAN UEs
IPSec Tunnels (between the WLAN UEs
and the ePDG)
and the ePDG)
GTPv2
Combination Supported for
Deployment?
Deployment?
IPv4
IPv4
IPv4
Yes
IPv4
IPv6
IPv6
Yes
IPv4
IPv6
IPv4
Yes
IPv4
IPv4
IPv6
Yes
IPv6
IPv4
IPv4
Yes
IPv6
IPv6
IPv6
Yes
IPv6
IPv6
IPv4
Yes
IPv6
IPv4
IPv6
Yes
IPv4v6
IPv4
IPv4
Yes