PDN Gateway Overview
Features and Functionality - Base Software ▀
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
49
Identification of true destination in the case of terminating proxies, where shallow packet
inspection would only reveal the destination IP address / port number of a terminating proxy.
De-encapsulation of upper layer protocol headers, such as MMS-over-WTP, WSP-over-UDP,
and IP-over GPRS.
Verification that traffic actually conforms to the protocol the layer 4 port number suggests.
Rule Definitions
: User-defined expressions, based on protocol fields and/or protocol-states, which define what
actions to take when specific field values are true. Expressions may contain a number of operator types (string,
=, >, etc.) based on the data type of the operand. Each Ruledef configuration is consisting of multiple
expressions applicable to any of the fields or states supported by the respective analyzers.
Rule Bases
: a collection of rule definitions and their associated billing policy. The rule base determines the
action to be taken when a rule is matched. It is possible to define a rule definition with different actions.
Mediation and Charging Methods
To provide maximum flexibility when integrating with billing mediation systems, ECS supports a full range of charging
and authorization interfaces.
Pre-paid
: In a pre-paid environment, the subscribers pay for service prior to use. While the subscriber is using
the service, credit is deducted from subscriber's account until it is exhausted or call ends. The pre-paid
accounting server is responsible for authorizing network nodes (GGSNs) to grant access to the user, as well as
grant quotas for either time connected or volume used. It is up to the network node to track the quota use, and
when these use quotas run low, the network node sends a request to the pre-paid server for more quota.
If the user has not used up the purchased credit, the server grants quota and if no credit is available to the
subscriber the call will be disconnected. ECS and DCCA manage this functionality by providing the ability to
setup quotas for different services.
Pre-paid quota in ECS is implemented using DIAMETER Credit Control Application (DCCA). DCCA
supports the implementation of real-time credit control for a variety of services, such as networks access,
messaging services, and download services.
In addition to being a general solution for real-time cost and credit control, DCCA includes these features:
Real-time Rate Service Information
- DCCA can verify when end subscribers' accounts are exhausted
or expired; or deny additional chargeable events.
Support for Multiple Services
- DCCA supports the usage of multiple services within one subscriber
session. Multiple Service support includes; 1) ability to identify and process the service or group of
services that are subject to different cost structures 2) independent credit control of multiple services
in a single credit control sub-session.
Refer to the
Diameter Credit Control Application
section for more information.
Post-paid
: In a post-paid environment, the subscribers pay after use of the service. A AAA server is responsible
for authorizing network nodes (GGSNs) to grant access to the user and a CDR system generates G-CDRs/eG-
CDRs/EDRs/UDRs or Comma Separated Values (CSVs) for billing information on pre-defined intervals of
volume or per time.
Important:
Support for the Enhanced Charging Service requires a service license; the ECS license is included in
the P-GW session use license. For more information on ECS, refer to the
Enhanced Charging Service Administration
Guide
.
