Cisco ASR 5000 Series, Обзор продукта

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HRPD Serving Gateway Overview
▀ Features and Functionality - Base Software
▄ Cisco ASR 5000 Series Product Overview
OL-22938-02
establishes the auxiliary RLP and A10' connection to the HSGW. Once that is accomplished traffic can begin flowing
across the dedicated bearer.
Network Access and Charging Management Features
This section describes the following features:
EAP Authentication (STa)
Rf Diameter Accounting
AAA Server Groups
Dynamic Policy and Charging: Gxa Reference Interface
Intelligent Traffic Control
EAP Authentication (STa)
Enables secure user and device level authentication with a 3GPP AAA server or via 3GPP2 AAA proxy and the
authenticator in the HSGW.
In an evolved HRPD access network, the HSGW uses the Diameter based STa interface to authenticate subscriber
traffic with the 3GPP AAA server. Following completion of the PPP LCP procedures between the UE and HSGW, the
HSGW selects EAP-AKA as the method for authenticating the subscriber session. EAP-AKA uses symmetric
cryptography and pre-shared keys to derive the security keys between the UE and EAP server. EAP-AKA user identity
information (NAI=IMSI) is conveyed over EAP-PPP between the UE and HSGW.
The HSGW represents the EAP authenticator and triggers the identity challenge-response signaling between the UE and
back-end 3GPP AAA server. On successful verification of user credentials the 3GPP AAA server obtains the Cipher
Key and Integrity Key from the HSS. It uses these keys to derive the Master Session Keys (MSK) that are returned on
EAP-Success to the HSGW. The HSGW uses the MSK to derive the Pair-wise Mobility Keys (PMK) that are returned
in the Main A10' connection to the e-PCF. The RAN uses these keys to secure traffic transmitted over the wireless
access network to the UE.
After the user credentials are verified by the 3GPP AAA and HSS the HSGW returns the PDN address in the VSNCP
signaling to the UE. In the e-HRPD connection establishment procedures the PDN address is triggered based on
subscription information conveyed over the STa reference interface. Based on the subscription information and
requested PDN-Type signaled by the UE, the HSGW informs the PDN GW of the type of required address (v6 HNP
and/or IPv4 Home Address Option for dual IPv4/v6 PDNs).
Rf Diameter Accounting
Provides the framework for offline charging in a packet switched domain. The gateway support nodes use the Rf
interface to convey session related, bearer related or service specific charging records to the CGF and billing domain for
enabling charging plans.
The Rf reference interface enables offline accounting functions on the HSGW in accordance with 3GPP Release 8
specifications. In an LTE application the same reference interface is also supported on the S-GW and PDN Gateway