Prepaid Extensions to RADIUS (draft-lior-radius-prepaid-extensions-10.txt) A. Lior Bridgewater Systems P. Yegani Cisco Systems K. Chowdhury Starent Networks H. Tschofenig Siemens A. Pashalidis Siemens

What’s new in -10 … Aligned with Diameter Credit Control i.e. RADIUS Prepaid now supports:  Balance check: are sufficient funds available for a given service in the user account?  Price enquiry: how is a given service rated? The response AVP returns the cost information for the requested service Detailed example message flows –Simple flow –Flow with tariff switching –Flow with resource pools, rating groups, and multiple services

What’s new in -10 Contains high level description of translation agent between RADIUS prepaid and Diameter Credit Control for scenarios below:  RADIUS PP-based client, Diameter CC-based AAA infrastructure  Diameter CC-based client, RADIUS PP-based infrastructure No more reliance on “Authorize-Only”

RADIUS Design Guidelines (Ref: draft-weber-radius-attr-guidelines-02.txt) Backwards Compatibility [6.1] Intermediate nodes [6.1.1] Dictionary-based implementations [6.1.2] Unaware endpoints [6.1.3] Existing Vendor-Specific Attribute Usage [6.2] Transport Impact [6.3] Diameter Compatibility [6.5] Security [6.6] Hence it appears that all guidelines are respected (pending peers review)

RADIUS PP vs DIAMETER CC RADIUS Prepaid uses a grouped AVP (as does Diameter Credit Control)  see section Translation Agent in {Diameter CC-based client, RADIUS Prepaid-based infrastructure} case not described (yet)  Is tricky due to many Diameter Credit Control AVPs and few RADIUS Prepaid Attributes  Some AVPs are semantically only partially equivalent

Open issues Translation between RADIUS Prepaid and Diameter Credit Control  Diameter TCP-based; messages include quota difference from previous quota  RADIUS: UDP-based; message include cumulative quota since start of session Hence; either translation agent needs per session state, or excessively large ‘state’ AVPs (e.g. in multiple services scenario)

Next Step Should this be a WG item?