Challenges in Management of IP Multimedia Subsystem (IMS)

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Challenges in Management of IP Multimedia
Subsystem (IMS)

• September 30, 2006

For more information, contact David P.
Strand CMTS Lucent Technologies Bell
Labs 1-(623)-581-4479 strandd_at_lucent.com
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Overview

• IMS Overview
• Management Considerations for IMS
• Fault Management
• Configuration Management
• Accounting Management
• Performance Management
• Summary

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3GPP/3GPP2 IMS Network Architecture
PDN
Control
Mb/36/38
IP Core Network Multi-media Subsystem (IMS)
Mb/42
Bearer
MGW
MRFP
Mb/34
Blue 3GPP definition Red 3GPP2
definition Black Common definition Green Not
Common
Mb/33
Mb/32/37
Mc/30
Mk/tbd
Mp/25
Mm/tbd
Mj/17
PSTN / PLMN
MRFC
MGCF
BGCF
Mr/24
PSTN/26
Mi/ee
Mg/17
Packet Data Subsystem
Mw/ dd/ff
Go/28
CSCF
PDF ?
OSA-AS
OSA-SCS
ISC/12
OSA
23
Cx/16
SIP-AS
Home Subscriber Server ?

• For 3GPP, the PDF is within the P-CSCF. For
  3GPP2, the PDF is a network entity of its own.
• For 3GPP the HSS also contains HLR functionality
  which is not shown here. For 3GPP2 the AAA
  function shown in the HSS is a stand-alone
  entity.
• Additional interfaces exist in both the 3GPP and
  3GPP2 reference models but are not included in
  this proposal for harmonization.

AAA
Sh/7/11
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3
Radio Access Network
Databases
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IMS Functional Architecture

• IMS IS
• A VoIP Telephony and Multimedia Services
  Architecture
• Defined with Open Standard Interfaces -gt 3GPP and
  3GPP2
• Based on IETF Protocols (SIP, RTP, ..)
• Designed for Both Wireless and Wireline Networks
• A Solution for Service Transparency
• Capable of Interworking with PSTN and Legacy IN
  Based Services

Web Portal
Application Layer
Application Servers
Session Control
Centralized Databases
Session Control Layer
HSS
CSCF
Media Servers
Access Network
Media Control Gateways
Media and End Point Layer
CSCF Call Session Control Function HSS Home
Subscriber Server
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Fault Management

• Voice Quality Testing
• Some standards exist
• Approval not universal
• Issues in differentiating between network and CPE
  contribution to voice quality
• Multimedia Quality Verification
• Few standards exists for services involving
  multiple media
• Not a current issue, but will become one as
  complexity increases

fault detection
equipment diagnostics
fault reporting
voice quality testing
repair procedures
multimedia quality
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Configuration Management

• DNS/ENUM provisioning
• Problem space well-defined
• Standards well-defined
• Key impact lies in extending existing processes
  and procedures
• Trunk/Route provisioning
• Similar to mapping of trunk groups and members to
  DS1 facilities
• Opportunity to greatly simplify traditional trunk
  paradigms
• UE/CPE provisioning
• UE/CPE have significant intelligence
• Subscriber, service, and security data must be
  provisioned in CPE/UE
• Few standards exists

equipment provisioning
DNS/ENUM provisioning
subscriber provisioning
trunk/route provisioning
service provisioning
UE/CPE provisioning
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Accounting Management

• Usage Data Generation
• Different types of usage
• Event-based billing
• Different data formats
• Necessitates mediation functions
• Usage Data Collection
• Different collection mechanisms
• Generally utilizing file transfer
• Somewhat akin to AMADNS
• Call / Event Rating
• Affected by new types of usage
• May occur at different points in the billing flow
  (including within the network)

usage data generation
usage data collection
call / event rating
bill generation
bill rendering
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Performance Management

• Data Generation
• Numerous new measures
• Delay, lost packets, etc
• Traditional trunk measures
• Capacity Engineering
• Based on similar principles
• Data is significantly different
• Opportunity to size facilities based on coarser
  granularity than with traditional trunk paradigms
• Congestion Management
• Need a completely different paradigm
• Based on resource allocation
• RACF / RACS models provide the means
  implementations commencing

data generation
data collection
threshold alerting
capacity engineering
congestion management
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Summary

• Most aspects of IMS and IP-based network
  management are evolutionary, rather than
  revolutionary
• Traditional solutions can be easily extended to
  address many of the management problems
• However, introduction of IP technology in the
  core network introduces new management issues
  never encountered before
• The most significant of these deal with
• (a) the new role of UE/CPE, with greater
  intelligence
• (b) new trunk paradigms
• (c) congestion management, addressed via RACF /
  RACS solutions
• Security plays a far more prevalent role in IMS
  and IP-based networks