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Diameter Credit-control Application http://www.ietf.org/internet-drafts/draft-ietf-aaa-diameter-cc-00.txt Harri Hakala Juha-Pekka Koskinen John Loughney Leena Mattila Marco Stura. Goals. Support existing credit control solutions, for example, ones used in 3GPP
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Diameter Credit-control Application http://www.ietf.org/internet-drafts/draft-ietf-aaa-diameter-cc-00.txt Harri Hakala Juha-Pekka Koskinen John Loughney Leena Mattila Marco Stura
Goals • Support existing credit control solutions, for example, ones used in 3GPP • Support for generic credit control solutions, for example prepaid WLAN access. • Interwork with existing AAA protocols
Updates - Overview • After much discussion on the AAA WG mailing list, the document has been updated to accommodate Authorization-based requests for credit control. • We tried to address the following points: • Better clarify the scope of this application • Clarify all the definitions with special care to the Service Element one. • Make architectural changes and explain how AA messages are used etc. • Draw some flows with different use cases and different scenarios • Clarify that NAS will never issue price inquiry or credit check or refund. • Clarify failover procedures.
Main changes • Introduction & architecture diagram. • New commands & AVPs. • Updated protocol operation. • Updated state machines. • Added section on RADIUS/Diameter Credit-control Interworking, for support of legacy systems. • Updated examples.
Architecture 1 Service Element AAA and credit-control +----------+ +---------+ protocols +-----------+ +--------+ | End |<---->|+-------+|<------------>| AAA | |Business| | User | +->|| CC || | Server |->|Support | | | | || client||<-----+ | | |System | +----------+ | |+-------+| | +-----------+ | | | +---------+ | ^ +--------+ +----------+ | | CC protocol | ^ | End |<--+ | +-----v----+ | | User | +------>|Credit- | | +----------+ credit-control |control |--------+ protocol |server | +----------+
Architecture 2(Interworking) AAA +--------+ +---------+ protocol +------------+ +--------+ | End |<----->| Service |<------------>| AAA | |Business| | User | | Element | | Server | |Support | +--------+ +-->| | |+----------+|-->|System | | +---------+ ||CC client || | | | |+----------+| | | +--------+ | +------^-----+ +--------+ | End |<--+ credit-control | ^ | User | protocol | | +--------+ +-------V------+ | |Credit-control|--------+ | Server | +--------------+
New command, AVPs • <Credit-Control-Request>; <Credit-Control-Answer> • Used between the Diameter credit-control client and the credit-control server to request/answer credit authorization for a given service. • Renamed accounting AVPs to CC AVPs • New AVPs: • CC-Request-Number • used in matching credit control messages with confirmations • used in CCS to detect duplicate and out of sequence messages • CC-Request-Type • contains the reason for sending the Credit-control request message – initial request, update, termination, etc. • CC-Sub-Session-Id • Indicates multiple sessions for which credit control is applicable. • CC-Failover-Supported • Indicates if failover is supported by the server for on-going session • Credit-Control • included in AA requests when service element has credit control capabilities – indicates credit-authorization / re-authorization. • Validity-Time • contains the validity time of the granted service units.
To Do • Some editorial fixes identified. • Completeness & interworking check. • Additional review needed. • Improve graceful service termination support • Received the comment: • In many instances in the text the action to take when a user resources are no longer available is to terminate the session. That is one possible action, the other possible action is to restrict access (or direct the user) to a portal where they can recharge their account etc... • Enhancements to the Credit Control Session failure procedure
Flow for granting Prepaid Network Access End-User NAS (cc client) AAA Server CC Server |(1)User Logon |(2)AA Request (CC AVPs) | |------------------>|------------------->| | | | |(3)CCR(initial, CC AVPs) | | |------------------->| | | | (4)CCA(granted Units) | | |<-------------------| | |(5)AA Answer(granted Units) | |(6)Access granted |<-------------------| | |<----------------->| | | | | | | : : : : | |(7)CCR(update,used Units) | | |------------------->|(8)CCR (upd, used-units) | | |------------------->| | | |(9)CCA(granted Units) | |(10)CCA(granted Units)<------------------| | |<-------------------| | | (Auth. lifetime expires) | | | |(11) AAR (CC AVP) | | | |------------------->| | | | (12) AAA | | | |<-------------------| |
Flow for logging-off Prepaid Network Access End-User NAS (cc client) AAA Server CC Server |(13) User logoff | | | |------------------>|(14)CCR(term,used-Units) | | |------------------->|(15)CCR | | | | (term.,used-Units) | | |------------------->| | | | (16)CCA | | | (17)CCA |<-------------------| | |<-------------------| | | |(18)STR | | | |------------------->| | | | (19)STA | | | |<-------------------| |