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A Light Reading Webinar The Role of SIP in VOIP Services Wednesday, June 13, 2007 Hosted by Denise Culver Research Analyst Light Reading Sponsored by:
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A Light Reading Webinar
The Role of SIP in VOIP Services
Wednesday, June 13, 2007
Hosted by
Denise CulverResearch Analyst
Light Reading
Sponsored by:
SpeakersTony Downes
Principal Technologist, Network Protocol DivisionData Connection Limited
Todd MerschProduct Marketing Manager
Continuous ComputingDan Bantukul
Director of Product MarketingTekelec
Yaron EisensteinDirector, Marketing Solutions
TTI Telecom
NetworkingNetworkingProtocolsProtocolsDivisionDivision
Internet Internet ApplicationsApplications
DivisionDivision
Enterprise Enterprise ConnectivityConnectivity
DivisionDivisionProtocol software for OEMs
Communication application software for SPs
SNA software for OEMs and Enterprises
Class 4/5 softswitch solutions for IOCs/CLECs
300+ deployments3m subscriber capacity
Data Connection Ltd. (DCL)
Protocol Software
TrilliumProfessional Services
AdvancedTCA & CompactPCI Hardware
IntegratedSystems
Over 150 Customers Worldwide
www.ccpu.com
Continuous Computing
Visit us onlinewww.tekelec.com
Deployed in more than 300 networks. Serving more than a billion telephone customers.For over one billion
mobile and fixed-line subscribers around
the world, their call or text message arrives
at its intended destination thanks to a
TEKELEC solution.
TTI Telecoms Netrac portfolio delivers a proactive, customer-centric approach to service assurance and network management
Netrac's service assurance solution is uniquely positioned to converge legacy, next-generation, and IMS-based networks
Publicly traded OSS vendor with more than 15 years experience in providing OSS solutions to the telecom industry
TTI Telecoms customer base consists of global Tier-one and Tier-two service providers worldwide
Agenda
Fundamentals of SIP Outstanding enterprise & telecom
applications for SIP The importance of next-generation networks The role of SIP in service quality monitoring Q&A
SIP Overview SIP is signaling only = control plane
Provides signaling for calls, messaging & presence Does not carry media (RTP/RTCP)
Text-based protocol derived from research on multi-party conferences in 1990s Core function defined by IETF RFCs (3261, etc.) Higher-level features & conformance sets defined by
organizations including ETSI & MSF
Strengths Extensible feature set, including authentication framework Support for nomadic users Media abstraction Flexible distribution of function & scaleability
Same messages throughout network >>> simplicity
SIP Signaling Example
Proxy looks up AOR (address of record) in its registration database and routes signaling to registered endpoint
SDP offer/answer to negotiate the media RTP/RTCP carries the media directly between the endpoints
RTP
INVITE sip:[email protected]+ SDP offer
INVITE sip:[email protected]+ offer
sip.dataconnection.com
200 OK+ SDP answer
200 OK+ answer
More Complicated SIP Scenario
Heterogeneous network Low bandwidth links Multiple security domains
ServiceProvider
Internet
3G
SBC
SBCSBC
Class 5
NAT / Firewall
SIP Server
IP PBXEnterpriseSOHO
3G MobileSIP-T
MGCP
Service Provider
SIPRTP
RTP
Current SIP Challenges IMS SIP provides signalling for calls, messaging & presence
FlexibilityChosen for its Abstraction between layers
Ease of function distribution
InternetPSTN GSM
3G
SIP initially was designed for the Internet
But telephone networks are different
Open Homogeneous IP Network Complex Heterogeneous Network
SIP IMS Requirements
SIP
Guaranteed QOS
Charging mechanisms CommercialCapabilities
Security to prevent theft & DOS
PSTN & LegacyFeatures
Legacy services & business models
Caller-ID
Lawful intercept
Privacy
Emergency callhandling
Interoperability with legacy devices
Architectural Differences
Low bandwidth links
Monitoring of inter-operator links
NAT & firewall traversal
Access network traversal
Developing Products for IMS IMS-compliant SIP stack/toolkit e.g., SIP
SIGCOMP AKA/MD5 IPv6 P-headers Non-standard behavior e.g., proxy can release calls
Application enhancements e.g., SBC Application support for P-headers & other extensions IMS architecture: reference points to billing, policy, etc. Protocol interworking between IMS & non-IMS variants
SIP Pervasiveness
Relative Market Size Represents Relative Market Size Represents New Product Shipments New Product Shipments
Low Growth High Growth
SS7
VOIPSIP
2008
2010
2009
SIPGrowth
SIP Peer-to-Peer Applications Each peer acts as a SIP registrar,
user agent & proxy
Each peer maintains registration information via distributed hashing table (DHT) algorithms
Peers refresh regularly to maintain:
Location information Node availability
Supports value-added services (e.g., conferencing, voicemail, etc.)
VAS server acts as another peer Multiple solutions presented
depending on service type
SIP Peer-to-Peer Applications Benefits
Highly reliable & scaleable No single point of failure
Low cost of ownership No maintenance or
configuration Free- or low-cost client
software No need for monolithic central
servers Interoperable
Works with other SIP-based VOIP systems
Not true of P2P systems, like Skype
Challenges Security
DOS prevention Malicious P2P nodes
Authentication & authorization E-mail/password based Certification standards in
work Ensuring QOS
Call setup latency Efficient mixing of services
Next Generation Network
Softswitch(Call Agent,
MGC)
Co-Existence And Cross-Connect Of Legacy PSTN/CS Wireless And Pure IP Networks
SG For Signaling Conversion MG For Data Conversion
Centralized Set Of SIP-based Application Servers
General App Server Specific Feature Server Media Server
Functional Architecture Grouping Of Functions Up To
Network Designer Or Equipment Manufacturer
Lends Itself To Bladed Standardized HW Components
Legacy And IP Signaling Requirements
SIP, RTP, MGCP/H.248 => IP SS7, TDM, SIGTRAN => Legacy
PSTNWireless
SG
MG
Application Server
IPNetwork
Feature Server
Media Server
SIP
SIP
SIP
MGCP/H/248
MGCP/H.248
MGCP/H.248
SS7
SIGTRANRTP
MGCP/H.248
TDM
Next-Generation Networks Benefits
Transition from CS to PS IP backbone
Reduced cost of IP transport
Expedited new service deployment
Substantial bases of vendors & tested products
Foundation for future transition to IMS
Challenges Large initial investment Complex array of new
hardware & software Management of legacy
& NGN infrastructure OSS & BSS integration SIP performance &
reliability Security
IP Multimedia Subsystem
SCP
PSTN
LE TE
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PSTN CS
GSM 3G/ GPRS
PLMN CS PLMN
PS
BBWireline
MSCGMSC
HLR
SCP
SGSN GGSN
HLR
SCP
IP
MM IP
SMSCMMSC
USSD
BB Wireless
Carrier Grade IP N/etwork
PSTN CS
PLMN CS
PLMN PS
BBWireline
IP
MM IPBB
Wireless
MSC server
MGW
SMSC
HSSx CSCF
MGCFMRFC
MGW
MRF
SGW
IP/MPLS
OSA AS
IM-SSF
IMS EnablersSIP AS
SCS
Separation of transport, control & application layers
Standard interfaces between each layer/function
Access independence provided via array of gateways
Signaling simplification with SIP as core technology
IP Multimedia Subsystem Benefits
Ubiquitous service delivery
Consolidated mobile & fixed-core network
Rapid delivery of new services
Leverage IT/Internet innovation into telecom services
Standardized interfaces for vendor interoperability
Challenges True interoperability Confusing array of
specifications End-to-end security &
QOS Management of legacy
& IMS infrastructure SIP performance &
reliability Business-case
realization
Audience Poll #1Does your company have plans to implement
into its products or networks any of the following?
SIP only within the next year SIP & IMS within the next year SIP only within the next 2 years SIP & IMS within the next 2 years We have no plans to implement SIP or IMS
PSTNRegion
PSTNRegion
Cost reduction at core through VOIP
PSTNRegion
SIPPBX
PBX
IADVOIPEnd-Point
Expansion of VOIP to enterprise & residential
SIPServices
Introduction of services based on SIP application servers
VOIP peering R4 MSC servers introduction
SBC
SBC
VOIP
VOIP
VOIP
EdgeProxy
EdgeProxy
RAN MG
A/Abis
RAN MG
A/Abis
MSCServer
NGN Scaleability
Current NGN Implementation
- IP layer routers- IP routing protocols- IP QOS controls
SIPAS
SIPAS
PSTNGW
MSCServers IPPBX
SIPEnd-Points
Multimedia Servers
DIP
SIPPayload
Softswitch
Current NGN Implementation
- IP layer routers- IP routing protocols- IP QOS controls
SIPAS
SIPAS
PSTNGW
MSCServers IPPBX
SIPEnd-Points
Multimedia ServersApplicationIntelligent
NetworkIntelligent
BusinessIntelligent
SubscribersIntelligent
Softswitch
NGN Mapping to OSI Model
Layer 1Physical
Layer 2Data Link
Layer 3Network
Layer 4Transport
Layer 5Session
Layer 6Presentation
Layer 7Application
OSI NGNProtocols
Video, Voice, DataIM etc.
IP
TCP/UDPSCTP
SIP
SDP
Ethernet
802.x
Intelligent
Transport
Layer 1Physical
Layer 2Data Link
Layer 3Network
SIP Signaling Router
Layer 1Physical
Layer 2Data Link
Layer 3Network
Layer 4Transport
Layer 4Transport
Layer 5Session
Session RoutingEngine
IP RoutersIP Switches
NGN 2.0: Dedicated SSR Session Layer
Multimedia Servers
- IP layer routers- IP routing protocols- IP QoS controls
SIPAS
SIPAS
Softswitch
PSTNGW
MSCServers IP
PBX
SIPEnd-Points
Session RoutingEngine
Session RoutingEngine
Session SetupURI Routing
Service OrchestrationIOT point
Media-Independent Session Setup
SSR
SSR
SSR
SSR
Media Path (RTP)
Media Path
(RTSP)
SIP Path
MediaServer
Single Protocol Interworking Point
New SIPelement
IOT # 1IOT # 2
IOT # 3
IOT # 4 New SIP
element
SSR1 IOT
With SIP Signaling Router (SSR)With SIP Signaling Router (SSR)NO SSRNO SSR
Evolution/InterworkingPath to IMS
S-CSCF
P-CSCF
I-CSCF
IMSSIP AS
IMSSubscribers
IMS
SSR
NGNSubscribers
NGN
ISC
Mw
MwCx/Dx
An IMS subscriberuses NGN services
Audience Poll #2What is the most pressing problem with
next-generation networks that a SIP signaling router should solve?
Simplifying route provisioning within softswitches Easing the introduction of new SIP network
elements into the NGN Ability to support NGN in the multimedia
infrastructure Facilitating interworking between NGN & IMS Implementing number portability within the NGN
Service Quality Monitoring:The Bigger Picture
Packet delay Packet delay variation Packet loss ratio Packet error rate
Session Success/Failure Metrics
Session timers Metrics
Session Timers Metrics
Session Efficiency Metrics
M
O
S
C
C
I
E
-
M
o
d
e
l
P
E
S
Q
QOS Mechanism
QOS Monitoring
QOS Benchmarking
QOS Service-Level Agreement
SIP Monitoring:Holistic Approach to SQM
Understand customers experience Performance and quality indicators for
evaluating different segments of service usage
Be proactive with useable metrics Identify quality impairments before
customers have noticed
SLA monitoring Comparable metrics for internal &
partner SLA monitoring
Do my sessions meet quality
expectations?How long does ittake to connect?
Why does my session keep
dropping?
How fast ismy service restored?
What performancelevel is my session
operating at?
Analyzing a SIP Sessions Performance
SIP timers should at least match (if not surpass)
familiar traditional telephony timers
INVITE: sip:[email protected]:
[email protected]: sip:[email protected]
100 - Trying
180 - Ringing
Rings180 - Ringing
200 - OK Answers200 - OK
ACK
BYEHangs up
200 - OK
User A
User B
Proxy
Talking TalkingRTP
200 - OK
REGISTER: sip:[email protected]
401 - Unauthorized
REGISTER: (add credentials)
Registration Request Delay
(RRD)
Session Request
Delay (SRD)
Session Disconnect
Delay (SDD)
Session Duration Time
(SDT)
Session Establishment Rate
(SER)
SIP Monitoring Life CycleSession
Processing
Metric Dimensioning
& Creation
Service Degradation
Rules
Customers
Customer groups
Services
Service levels
Domains
Partners
Equipment type
Root-Cause Isolation
SIP Performance Indicators
Session Initiation Session Progress Session Termination
Performance indicators provided for VOIP telephone calls, multimedia distribution & multimedia conferences
Registration Request Delay (RRD)
Session Request Delay (SRD)Post-Dial Delay (PDD)
Average hops/ INVITE (AHI)
Session Duration Time (SDT)Call Hold-Time (CHT)
Session Disconnect Delay (SDD)
Session Disconnect Failure (SDF)Cut-off Calls
Session Establishment Rate (SER)
Answer Seizure Rate (ASR) Network Efficiency Rate (NER)
Session Establishment Efficiency Rate (SEER)
Ineffective Session Attempts (ISA)
Session Defects/ million (SPM)
Session Completion Rare (SCR)
Session Success Rate (SSR)
Call Completion Rate
Call Success Rate (CSR)
Service Degradation,Detection & Isolation
Detecting service degradation effectively
Cut-off calls > 0.3 of total calls the last hour
Current ASR < 75% of average ASR for the last 4 weeks
Generating operations, engineering & business alarms
Threshold management Abatement threshold (hysteresis) Isolating root cause of poor customer
experience with drill-down Identify CDR contribution to aggregated result Immediate attention of customer support
SIP: End-to-End Performance Summary
The Challenge
Monitoring Approach
SolutionBenefits
Four phases of SIP monitoring life cycle:
Evaluate customers experience
Be proactive with actionable metrics
Manage customers& inter-connectivity SLAs
Implementingend-to-end
service quality monitoring
in SIP-based networks
Session processing Metric dimensioning
& creation Service degradation
rules Root-cause isolation
Audience Poll #3
What should be the preferred method for SIP-based network quality monitoring?
Testing results from SIP analyzers & emulators Examine CDRs/IPDRs generated by network
devices Calculate KPIs/KQIs of the SIP signaling layer Use subjective live test calls
Q&A
A Light Reading Webinar The Role of SIP in VOIP ServicesSpeakersData Connection Ltd. (DCL)Continuous ComputingAgendaSIP OverviewSIP Signaling ExampleMore Complicated SIP ScenarioCurrent SIP Challenges IMSSIP IMS RequirementsDeveloping Products for IMSSIP PervasivenessSIP Peer-to-Peer ApplicationsSIP Peer-to-Peer ApplicationsNext Generation NetworkNext-Generation NetworksIP Multimedia SubsystemIP Multimedia SubsystemAudience Poll #1NGN ScaleabilityCurrent NGN ImplementationCurrent NGN ImplementationNGN Mapping to OSI ModelNGN 2.0: Dedicated SSR Session LayerMedia-Independent Session SetupSingle Protocol Interworking PointEvolution/Interworking Path to IMSAudience Poll #2Service Quality Monitoring:The Bigger PictureSIP Monitoring:Holistic Approach to SQMAnalyzing a SIP Sessions PerformanceSIP Monitoring Life CycleSIP Performance IndicatorsService Degradation,Detection & IsolationSIP: End-to-End Performance SummaryAudience Poll #3Q&A