Vitalis G'O

1
Charging QoS-Enabled Services in Inter-domain IMS
Frameworks

• Vitalis G.O
• Neco Ventura

Department of Electrical Engineering University
of Cape Town
2
Introduction

• QoS requirements in IMS Frameworks
• Inter-domain service brokering
• Pricing IMS services
• Policy and charging control 3GPP approach
• Relevant Protocols
• Execution plan
• Work in standards

3
IMS QoS Requirements

• QoS for media plane delay, jitter, and
  throughput
• QoS for IMS signaling
• Pricing and charging relates to QoS
• Policy and charging control done together

4
Inter-domain Service Brokering

• AD1 AN1CN1
• AD2 AN2CN2
• AD1 outsources AN1 users to AD2 on AN2
• QoS or price triggered
• Inter-domain signalling between IM1 and IM2 on
  Mm reference point

5
Pricing the IMS

• Which traffic to charge? What model to use?
• Flat rate for IMS session traffic
• Usage based charges for bearer plane traffic
• Predictable access network-dependent charges
• Retain low Internet charges for core network
  traffic

6
Core Network Prices

• AD1 and AD2 provision resources from different
  ISPs using long term SLAs
• Abstraction ISP sells bandwidth in aggregate
  blocks to AD1 and AD2
• Admission cost component rises with no. of sold
  BW blocks

7
Profitable Condition

• PN 0
• I sessions
• J CoS
• N users
• T time
• V volume of traffic
• B bandwidth blocks

8
Outsource Triggers

• Link failure calls dropped, blocked, failed
• Revenue vs. cost imbalance provisioned resources
  to cost more than revenue from extra users

9
Benefits and Conditions for Outsourcing

• Conditions
• PS gt PN
• Candidate network must offer lower per flow
  charges for outsourced sessions
• Benefits
• Increased revenue for both operators
• Boosted user satisfaction

10
Requirements for Outsourcing

• Inter-domain policy and charging control message
  interaction over the Mm reference point

11
Outsourcing Transactions

• SDP negotiation (request) between client and
  custodian network
• SDP request (required QoS, preferred access
  network etc.) and price offer to candidate
  network
• SDP answer and AA parameters for client from
  candidate network
• SDP answer to client with instruction to attach
  to candidate network
• Registration on candidate network subscriber
  information exchange
• IMS session setup continuation via candidate
  network
• Accounting session initiation for IMS and media
  traffic

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Relevant Protocols and Specifications

• SIP - IETF RFC3261
• DIAMETER IETF RFC3588
• SDP IETF RFC3264
• DiffServ IETF RFC2475
• 3GPP TS 23.203 Policy and charging control

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• Questions and Comments