Pdsn/Ha; Basic Operation; Network Interfaces - Cisco ASR 5000 Series Administration Manual

▀ Network Deployment(s) and Interfaces
• HSS: The HSS (Home Subscriber Server), is the master user database that supports the IMS network entities that
handle calls. It contains subscription-related information (subscriber profiles), performs authentication and
authorization of the user, and provides information about the subscriber's location and IP information.
• Femtocell Convergence Server: The Femtocell Convergence Server (FCS) is an IMS application server that
provides legacy Telephony Application Services (TAS) to 1x femtocell subscribers via SIP, including voice
services and voice feature delivery. The femtocell convergence server also manages idle and active mode
mobility for 1x subscribers as they move into and out of range of FAP coverage. It functions as an MFIF
(MAP-Femtocell Interworking Function) and interfaces with the HLR for 1x subscriber authentication. It
appears as an IMS application server to the S-CSCF and as a serving MSC to the HLR.
• Media Gateway: The Media Gateway terminates bearer channels from the circuit-switched network and media
streams from the packet-switched network. It can support media conversion, bearer control, and payload
processing (e.g., using codecs, echo cancellers, and conference bridges).

PDSN/HA

The PDSN/HA enables femtocell subscribers to receive packet data services in the mobile operator's core network. In
most cases, these services are the same as those available via the mobile operator's macro network.

Basic Operation

When a FAP powers up, it uses DNS resolution to resolve its pre-configured FQDN of the FNG and obtain the FNG's
IP address. It then initiates IPSec tunnel establishment over the broadband access network. The IPSec tunnel terminates
at the FNG.
The FAP receives an IPv4 address known as the Tunnel Inner Address (TIA) from the FNG during the first IPSec tunnel
establishment. The FNG assigns the TIA from its own IPv4 address pool. Once an IPSec tunnel is established, the FAP
uses the TIA in all its SIP messages and to obtain configuration data from its FMS. The FNG is agnostic in regard to the
protocol used between the FAP and its FMS, and simply forwards packets between the FAP and the FMS over the
secure connection.
The 1x FAP performs P-CSCF discovery via a DHCP server per RFC 3319, or it may receive the IP address of the P-
CSCF from the FMS. Once the FAP gets the P-CSCF address, it initiates SIP registration with the IMS core network.
When a UE attaches to the FAP, it performs 1x registration with the IMS core network.

Network Interfaces

The following table provides descriptions of the network interfaces supported by the FNG in a CDMA2000 network.
Table 1. Network Interfaces in a CDMA2000 Network
Interface Description
▄ Cisco ASR 5000 Series Femto Network Gateway Administration Guide
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Femto Network Gateway Overview
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