Cisco Cisco Packet Data Interworking Function (PDIF)
Evolved Packet Data Gateway Overview
▀ Features and Functionality
▄ ePDG Administration Guide, StarOS Release 18
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1. If the responder's policy does not allow it to accept any part of the proposed Traffic Selectors, it responds with a
TS_UNACCEPTABLE Notify message.
2. If the responder's policy allows the entire set of traffic covered by TSi and TSr, no narrowing is necessary, and
the responder can return the same TSi and TSr values.
3. If the responder's policy allows it to accept the first selector of TSi and TSr, then the responder MUST narrow
the Traffic Selectors to a subset that includes the initiator's first choices.
4. If the responder's policy does not allow it to accept the first selector of TSi and TSr, the responder narrows to an
acceptable subset of TSi and TSr.
All these 4 cases will be supported with the exception that at any point of time maximum of four traffic selector per
protocol (combination of IPv4 and/or IPv6) will be supported in a single CHILD SA.
protocol (combination of IPv4 and/or IPv6) will be supported in a single CHILD SA.
When narrowing is done, if there are several subsets are acceptable, GW will respond back with first 4 acceptable
subsets and it will not support ADDITIONAL_TS_POSSIBLE notification.
subsets and it will not support ADDITIONAL_TS_POSSIBLE notification.
.
Static IP Address Allocation Support
ePDG supports the static UE IP address communicated by AAA to ePDG over SWm interface (as Served-Party-IP-
Address AVP in DEA) and ePDG communicates the same to PGW over S2b interface (as PAA IE of create session
request GTP message and Home Network Prefix/IPv4 Home Address in PBU for PMIPv6 case).
Address AVP in DEA) and ePDG communicates the same to PGW over S2b interface (as PAA IE of create session
request GTP message and Home Network Prefix/IPv4 Home Address in PBU for PMIPv6 case).
This feature is applicable for both GTPv2 and PMIPv6 based implementation.
It shall be AAA server functionality to provide the static PGW IP address, when the UE IP address is provided statically
so that same PGW is selected which have the static IP pool corresponding to UE address. ePDG will continue with call
establishment and will not be validating the AAA provided PGW allocation type. It is the discretion of PGW to
accept/reject call in case the requested static IP address is not available at the PGW.
so that same PGW is selected which have the static IP pool corresponding to UE address. ePDG will continue with call
establishment and will not be validating the AAA provided PGW allocation type. It is the discretion of PGW to
accept/reject call in case the requested static IP address is not available at the PGW.
During handoff calls the priority should be given to UE provided IP address over the ones statically provided by AAA
server as the subscribed QoS profile at AAA may not be updated. When UE is offloaded from LTE the IP address
provided in LTE to UE should be given priority in WIFI over the AAA provided values. WIFI to WIFI handoff is not a
requirement so inter ePDG service handoff is not a valid use-case.
server as the subscribed QoS profile at AAA may not be updated. When UE is offloaded from LTE the IP address
provided in LTE to UE should be given priority in WIFI over the AAA provided values. WIFI to WIFI handoff is not a
requirement so inter ePDG service handoff is not a valid use-case.
All the three PDN Types UE static IP address are supported including the IPv4, IPv6 and IPv4v6.
Table 9. ePDG Static IP Address support failure matrix
S.N UE requested
PDN Type
AAA provided
PDN type
PDN type
AAA provided Static
IP address type
IP address type
ePDG Action
1
v4
v4
v4
Call established for v4 PDN type using the AAA provided
static IP address.
static IP address.
2
v4
v4
v6
Call established for v4 PDN type but ignoring the AAA
provided IP address.
provided IP address.
3
v4
v4
v4v6
Call established for v4 PDN type and using v4 address
provided by AAA.
provided by AAA.
4
v4
v4v6
v4
Call established for v4 PDN type and using v4 address
provided by AAA.
provided by AAA.
5
v4
v4v6
v4v6
Call established for v4 PDN type and using v4 address
provided by AAA.
provided by AAA.