IMS & QOS IMS Alphabet Soup and the need for Unified Policy Management Matt Tooley CableMatrix Technologies, Inc.

3 Agenda Review of Quality of Service (QoS) IMS + QoS in theory Policy Management IMS + QoS in the real world Putting it all together Summary

4 Evolving Services Entertainment –IPTV, VOD, voice Communications –Voice, messaging, collaboration Security –DOS protection, device/user quarantine Managed Enterprise –Dynamic bandwidth allocation Fixed Mobile Convergence (FMC) –Service continuity, application and network-aware QoS Moving beyond conversational SIP services

5 Growing need for QoS Latency/Loss Sensitivity Bandwidth Consumption Legacy Internet Services Music Download Voice Game Download IPTV Streaming Video Utilitarian – weigh lightly on network More exciting – weigh heavily on the network Low-end Gaming Video Conferencing/Telephony Console Gaming Video Download

6 QoS 101 – What is QoS? Quality of Service (QoS) refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the application program. QoS is more than just bandwidth –Delay –Jitter –Priority –Packet loss

7 QoS 101 – Application Requirements Voice –Constant bit rate service –Low latency, low jitter –Little or no packet loss –Guaranteed bandwidth Streaming Media –Variable bit rate service –Low jitter, low packet loss –Guaranteed minimum bandwidth Real-time Gaming –Variable bit rate service –Low latency, low jitter –Low packet loss Web Surfing –Best Effort QoS Requirement

8 QoS 101 – QoS Models Differentiated Services (Diffserv) –Provisioned QoS model –Class of services –Prioritized Integrated Services (Intserv) –Signaled QoS model with admission control –Flow-based QoS –Parameterized

9 QOS Triggering Points – Push, Pull Push –QOS pushed from the network –Network server requests QOS upon service initiation Pull –QOS pulled by the user/user equipment –UE requests QOS upon service initiation

10 QoS Framework for NGN IMS Switching Core Core IP Network CPE Access Nodes IP Routers Policy Manager Application Function SIP QoS Control SIP

11 IMS UTRAN SGSN GGSN UE I-CSCF GoGi I-CSCF P-CSCF S-CSCF Mw HSS Cx SGW MGCF BGCF IMS- MGW Legacy/ PSTN Mk Mi Mg Mj Mn Gi MRF Gi Mr PDF Go Gq Other IP/ IMS network Mm Traffic Plane Control Plane IMS Architecture

12 BTS BSC SCIM (Service Broker Platform) RAN TRANSPORT PLANE CONTROL PLANE SERVICE PLANE HLR PDF SGSN Intranet/ Internet WLAN MG W Node BRNC PSTN PLMN MRFCS-CSCF I-CSCF P-CSCF BGCF MGCF HSS MG W MRFP GGSN IMS Architecture - Simplified QoS

13 IMS & QoS in Theory IMS elements involved with QoS –User Endpoint (UE) –P-CSCF / Application Function –PDF –Edge IP Router GGSN, BRAS, CMTS, Base station Access Network UE GGSN,CMTS, BRAS,ASN-GW Policy Decision Function P-CSCF Application Function QoS-related application-level parameters(e.g.SDP) Policy Set-up info Gq/Gq’ Policy Decisions Go Policy Decision Decisions concerning Service Based Local Policy Policy Enforcement Diffserv,Intserv QoS parameters,etc

14 IMS based QoS (1/3) IMS based QoS –Supports a minimum bandwidth required by a service based upon PDF’s QoS decision and IP edge node resources –PDF’s QoS decisions based upon IMS signaling and operator policy rules Application level E2E QoS negotiation –End-to-End QoS requirements are negotiated via SIP/SDP offer/answer model signaling

15 IMS based QoS (2/3) Mechanism for E2E QoS authorization –SDP Inspection SDP media parameters are examined based upon local policy, configuration of operators or user subscription If there are any media parameters which are not allowed on the network, CSCF returns a 4XX (Not Acceptable Here) response UE, P-CSCF, S-CSCF, and AS perform SDP inspection –Session Based Local Policy (SBLP) based authorization P-CSCF generates the service information from SDP and sends it to PDF PDF authorizes the QoS requirements from IMS-Proxy based on operator policy rules PDF saves authorization results PDF authorizes the QoS requirements for IP Edge Node based upon SBLP

16 IMS based QoS (3/4) UE P-CSCFS-CSCFAS SDP SDP Inspection SDP inspection performed based upon Local Policy SDP inspection performed based upon Local Policy or User Subscription AS checks SDP and request confirmation for resource reservation at the endpoint

17 IMS based QoS (4/4) Media Path

18 Policy Control Key to Managing QoS Business and network orchestration –Subscriber & network policy enforcement Media authorization interface –Standard interface between applications and the network for signaling QoS requests Real-time service execution –Dynamic network resource control enables assured delivery of services Enhanced network utilization –Intelligent admission control guarantees quality and maximizes transaction value Creates new business opportunities –Charging, partnering,…

19 Alphabet Soup 3GPP –Release 6: PDF – Policy Decision Function –Release 7: PCRF – Policy Control and Charging Function 3GPP2 –PCRF – Policy Control and Charging Function TISPAN –RACF – Resource Admission Control Function CableLabs –PS – Policy Server –PAM – PacketCable Application Manager WiMAX –Release 1: PF - Policy Function –Release 1.5: ???

20 IMS & QoS Ideal Case PDF CSCF UMTS Session Control Plane(SIP) Resource Control Plane

21 IMS & QoS Real World PDF CSCF PDF DSL/ Cable 3G WiMAX Session Control Plane(SIP) Resource Control Planes

22 Problems with this approach Requires CSCF to support multiple policy signaling interfaces CSCF needs to know information about the transport layer QoS Levers –3G & DSL – Min & Max bandwidth –Cable & WiMAX Shared Media Min & Max bandwidth Scheduling –Jitter & Latency No good support for non- SIP based services NAT PDF CSCF PDF DSL/ Cable 3G WiMAX Session Control Plane(SIP) Resource Control Planes

23 IMS & QoS Real World – The Solution CSCF (SIP) 3G Session Control Plane Application Function (non-SIP) Policy Server/Policy Decision Function WiMAXCable/ DSL Resource Control Plane Transport Plane

24 Benefits of Unified Policy Management CSCF is network agnostic –Does not need to know any transport layer information Enables seamless QoS handovers across networks –PDF has visibility of all network resources across all its networks Consistent service levels regardless of network –PDF converts QoS from network agnostic form to network specific form Supports services beyond SIP conversational services –IPTV, internet video, on-line gaming, …. Supports Policy Peering for inter-service provider services –Centralized policies minimizes interfaces across peering points

25 Summary Keys to success –QoS is required delivering services over IP –Policy management is required for orchestrating QoS requests for applications –Centralized policy management assures all applications work equally well regardless of the network

Thank-You Matt Tooley CTO CableMatrix Technologies, Inc (847)

27 Acronyms AF – Application Function AS – Application Server ASN-GW – Access Service Network Gateway BRAS – Broadband remote access server BS – Base station CMTS – Cable modem termination system CPE – Customer premise equipment DOS – Denial of Service E2E – End to End FMC – Fixed Mobile Convergence GW – Gateway IMS – IP Multimedia Subsystem PDF – Policy Decision Function PF – Policy Function QOS – Quality of Service SDP – Session Description Protocol SBLP - Session Based Local Policy SIP – Session Initiation Protocol