IMS

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(No Transcript)
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IMS QOS

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

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Agenda

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

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Evolving Services
Moving beyond conversational SIP 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

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

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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
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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

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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

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

IMS
HSS
Mm
I-CSCF
Cx
I-CSCF
Cx
Mw
S-CSCF
Mk
P-CSCF
Mr
Mi
MRF
Mg
Go
Gi
BGCF
Gq
Mj
MGCF
Gi
UTRAN
SGW
IMS- MGW
PDF
Mn
Go
Gi
Legacy/ PSTN
UE
SGSN
GGSN
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IMS Architecture - Simplified
SERVICE PLANE
SCIM (Service Broker Platform)
QoS
MRFC
S-CSCF
HSS
HLR
I-CSCF
CONTROL PLANE
P-CSCF
BGCF
PDF
MGCF
RAN
MGW
MGW
MRFP
Node B
RNC
GGSN
BTS
BSC
SGSN
Intranet/Internet
WLAN
TRANSPORT PLANE
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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

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IMS based QoS (1/3)

• IMS based QoS
• Supports a minimum bandwidth required by a
  service based upon PDFs QoS decision and IP edge
  node resources
• PDFs 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

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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

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

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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 ???

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IMS QoS Ideal Case
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IMS QoS Real World
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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

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IMS QoS Real World The Solution
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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

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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

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Thank-You

• Matt Tooley
• CTO
• CableMatrix Technologies, Inc
• http//www.cablematrix.com
• mtooley_at_cablematrix.com
• [phone]

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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