Terminology; Contexts; Logical Interfaces - Cisco ASR 5000 Series 3G Home NodeB Administration Manual

▀ Terminology

Terminology
This section defines some of the terms used in the chapters that follow.

Contexts

A context is a logical grouping or mapping of configuration parameters that pertain to various physical ports, logical IP
interfaces, and services. A context can be thought of as a virtual private network (VPN).
The system supports the configuration of multiple contexts. Each is configured and operates independently from the
others. Once a context has been created, administrative users can then configure services, logical IP interfaces,
subscribers, etc.for that context. Administrative users would then bind the logical interfaces to physical ports.
Contexts can also be assigned domain aliases, wherein if a subscriber's domain name matches one of the configured
alias names for that context, then that context is used.
Contexts on the system can be categorized as follows:
 Source context: Also referred to as the "ingress" context, this context provides the subscriber's point-of-entry in
the system. It is also the context in which services are configured. For example, in a 3G UMTS network, the
HNB access radio network containing the Home-NodeBs (HNBs) would communicate with the system via IuH
interfaces configured within the source context as part of the HNB-GW service.
 Destination context: Also referred to as the "egress" context, this context is where a subscriber is provided
connectivity to core network (such as access to the MSC, SGSN, GGSN etc.) as configured on HNB-GW
service and related services. For example, the system's destination context would be configured with the IuCS,
IuPS, Gn, Gi or IP offload interfaces facilitating subscriber data traffic to/from the core network (MSC, SGSN,
GGSN) or other PDN (Mobile Data Service or Internet.
 AAA context: This context provides AAA functionality for subscriber bearer contexts and/or administrative user
sessions and contains the policies and logical interfaces for communication between Security Gateway (SeGW)
and a 3GPP AAA Server or 3GPP AAA proxy (OCS/CGF/AAA/HSS) over AAA interface for authentication
and authorization procedures for Femto user.
In the roaming case, the 3GPP AAA Proxy can act as a stateful proxy between SeGW and 3GPP AAA Server.
The AAA server is responsible for transfer of subscription and authentication data for
authenticating/authorizing user access and UE authentication. The SeGW communicates with the AAA on the
PLMN using AAA interface.
For administrative users, authentication functionality can either be configured in the local context or be
authenticated in the same context as subscribers.
 Local context: This is the default context on the system used to provide out-of-band management functionality.

Logical Interfaces

This section describes the logical interface supported on HNB-GW.
▄ Cisco ASR 5000 Series 3G Home NodeB Gateway Administration Guide
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Important:
To ensure scalability, authentication functionality for subscriber sessions should
not be configured in the local context.
Understanding the Service Operation
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