Credit Control and Prepaid Applications

1
Credit Control and Prepaid Applications Avi
Lior Bridgewater Systems avi_at_bridgewatersystems.
com Parviz Yegani Cisco pyegani_at_cisco.com http
//www.ietf.org/internet-drafts/draft-lior-radius-
prepaid-extensions-00.txt
2
Motivation

• Prepaid Data Services are very important to
  Service Providers
• 3GPP
• 3GPP2
• WLAN
• AAA infrastructure is central
• 3GPP gt Diameter Credit Application (HSS)
• 3GPP2 gt RADIUS based IS-835 C
• WLAN gt RADIUS (WiFi Alliance)
• Deployments are happening today.

3
Requirements

• Service Portability
• Prepaid Data Service needs to be available
  anytime.
• At different locations.
• Using different access technologies.
• Service Continuity
• Prepaid Data Service should be continuous as
  users roam.
• Between different locations.
• Crossing different access network boundaries.
• Same or different technologies

4
Requirements

• More requirements such as
• No revenue leakage
• Support for multiple sessions
• Extensible to support different prepaid schemes
• Time, volume, others
• Good source of requirements
• Francis et al, Design Issues for Prepaid Data
  Service draft-francis-prepaid-00.txt

5
Prepaid Data Service Generic Architecture
6
RADIUS Implementations

• Access Request includes Prepaid Capabilities of
  the Access Dev
• Allocate initial quota during Access Accept
• Request of additional quotas (between access
  device and prepaid system)
• Some are proposing Accounting messages.
• Accounting is for recording not control.
• Requires accounting to be done in real-time.
• Pass-through mode vs. store and forward behavior
  for accounting message delivery
• In broad networks, we cant guarantee the
  real-time delivery of accounting messages!!!
• Use Access Request - Access Accept
• We know how this performs in broad networks.
• Use of Radius Dynamic Authorization CHIBA
• Disconnect Message (DM) to boot users off
  especially in mobile situations.
• Change of Filters (CoF) to restrict users access
  once the account is depleted -- So they can
  replenish their account (Spend more money)