Services - Cisco ASR 5000 Series Administration Manual

Understanding the Service Operation
A specific logical interface (configured within a particular context) to a physical port. Once the interface is
bound to the physical port, traffic can flow through the context just as if it were any physically defined circuit.
Static bindings support any encapsulation method over any interface and port type.
A service to an IP address assigned to a logical interface within the same context. This allows the interface to
take on the characteristics (i.e., support the protocols) required by the service. For example, a GGSN service
bound to a logical interface will cause the logical interface to take on the characteristics of a Gn interface
within a GPRS/UMTS network.
Dynamic binding associates a subscriber to a specific egress context based on the configuration of their profile or
system parameters. This provides a higher degree of deployment flexibility as it allows a wireless carrier to support
multiple services and facilitates seamless connections to multiple networks.

Services

Services are configured within a context and enable certain functionality. The following services can be configured on
the system:
GGSN services: GGSN services are configured to support both mobile-initiated and network-requested PDP
contexts. The GGSN service must be bound to a logical interface within the same context. Once bound, the
interface takes on the characteristics of a Gn interface. Multiple services can be bound to the same logical
interface. Therefore, a single physical port can facilitate multiple Gn interfaces.
FA services: FA services are configured to support Mobile IP and define FA functionality on the system.
The system supports multiple Mobile IP configurations. A single system can perform the function of a FA
only, an HA only, or a combined PDSN/FA/HA. Depending on your configuration, the FA service can create
and maintain the Pi interface between the PDSN/FA and the HA or it can communicate with an HA service
configured within the same context.
The FA service should be configured in a different context from the PDSN service. However, if the FA service
will be communicating with an HA that is a separate network element, it must be configured within the same
context as and be bound to the Pi interfaces that allow it to communicate with the HA.
LAC services: LAC services are configured on the system to provide Layer 2 Tunneling Protocol (L2TP) access
concentrator (LAC) functionality. LAC services can be configured and used within networks to provide secure
tunneling to an L2TP network server (LNS) on a remote PDN.
DHCP services: DHCP services are configured on a system to provide dynamic assignment of IP address to
PDP contexts through the use of the Dynamic Host Configuration Protocol (DHCP).
Following figure illustrates the relationship between services, interfaces, and contexts within the system for
GPRS/UMTS networks.
OL-22944-02
Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide ▄
Terminology ▀