1. 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)

2. David P. Strand * AP-NOMS 2006
Overview
IMS Overview
Management Considerations for IMS
Fault Management
Configuration Management
Accounting Management
Performance Management
Summary
9/30/2006
David P. Strand * AP-NOMS 2006

3. 3GPP/3GPP2 IMS Network Architecture
Control
PDN
Mb/36/38
Bearer
IP Core Network Multi-media
Subsystem (IMS)
Mb/42
MGW
Blue = 3GPP definition
Red = 3GPP2 definition
Black = Common definition
Green = Not Common
MRFP
Mb/34
Mb/33
Mb/32/37
Mk/tbd
Mc/30
Mp/25
Mm/tbd
MRFC
Mj/17
PSTN /
PLMN
BGCF
MGCF
Mr/24
PSTN/26
Mi/ee
Mg/17
Packet Data
Subsystem
Go/28
Mw/
dd/ff
PDF 
CSCF
OSA-SCS
OSA-AS
ISC/12 23
OSA
Cx/16
Home Subscriber
Server 
SIP-AS
AAA
For 3GPP, the PDF is within the P-CSCF. For 3GPP2, the PDF is a network entity of it’s 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.
Sh/7/11 UA 3 4
Radio Access
Network
Databases
9/30/2006
David P. Strand * AP-NOMS 2006

4. IMS Functional Architecture
IMS IS:
A VoIP Telephony and Multimedia Services Architecture
Defined with Open Standard Interfaces -> 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
Layer
Session Control
Centralized
Databases
CSCF
HSS
Access
Network
Media
Servers
Media Control &
Gateways
Media and
End Point
Layer
Other
Networks
CSCF – Call Session Control Function
HSS – Home Subscriber Server
9/30/2006
David P. Strand * AP-NOMS 2006

5. David P. Strand * AP-NOMS 2006
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
Legend:
no significant changes
some changes or minor issues
major changes or issues
9/30/2006
David P. Strand * AP-NOMS 2006

6. 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
Legend:
no significant changes
some changes or minor issues
major changes or issues
9/30/2006
David P. Strand * AP-NOMS 2006

7. 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
Legend:
no significant changes
some changes or minor issues
major changes or issues
9/30/2006
David P. Strand * AP-NOMS 2006

8. 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
Legend:
no significant changes
some changes or minor issues
major changes or issues
9/30/2006
David P. Strand * AP-NOMS 2006

9. David P. Strand * AP-NOMS 2006
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
9/30/2006
David P. Strand * AP-NOMS 2006