Assuring Performance of Carrier-Class Networks and Enterprise Contact Centers
SP-11: Ensuring Service Quality While Increasing RevenueFebruary 4, 2009Daniel Teichman
Senior Product Marketing ManagerVoice Service Assurance
Ensuring Service Quality While Increasing Revenue
• Service Quality Measurement• Getting from Measurement to Monitoring• Service Level Agreement (SLA) Benchmarking• SLA Reporting• VoIP Peering Examples• Summary
Testing and Monitoring LifecyclePre-servicelab testing
Pre-service testing
In-service monitoring
Field service testing for performance
Test service logic and operational functionality
Benchmarking service quality & performanceEnsuring ongoing network and service quality
Service Quality Measurement• Signaling• Media• Passive and / or Active Methodologies
Signaling Quality Measurements• Real-time analysis / reporting of call completion statistics
– Post-Dial Delay, Call Attempts, Calls Successfully Completed, Failed Calls, Answer Seize Ratio, Answer Bid Ratio, Network Efficiency Ratio, Call Setup time, Call Disconnect time, Minutes of Use
• Real-time analysis / reporting on protocol statistics:– SIP packets, SIP Invites, SIP Errors, SIP 1xx / 2xx/ 3xx etc, SIP
Registers, etc.
• Per call capture of signaling quality measures, retained storage for diagnostic and analysis purposes
Media Quality Measurements• More difficult to capture than signaling quality measures
– Includes RTP, as well as DTMF (RFC 2833) and fax (T.38)
• Real-time analysis / reporting of packet and call statistics– Packets Received, Lost, Duplicate, OOS– Jitter, Burst; Gap, Mean Opinion Score (MOS)– Instantaneous or Worst point in call as well as Average per call
• Per call capture of media quality measures, retained storage for diagnostic and analysis purposes
Getting From Measurement to Monitoring
• Measurement gives you data – lots of it!
• Monitoring create value from measurement data. It gives you information for diagnosis, analysis and reporting
• Monitoring enables pro-active behaviors, enhances reactive behaviors
• Correlation, data segmentation and automatic notification of service issues are the three keys to success
Correlation per Call / Session
• Correlate signaling across both trusted and untrusted sides of SBC• Complicated call flows, e.g. SBCs can/will change call Ids• Measure RTP across both trusted and untrusted sides of SBC
Data Segmentation• Network-wide assessment is not sufficient for specific SLAs
• Data segmentation is a mandatory requirement– Per network segment or component– Per interconnect point – Per customer (typically large enterprise)
• Should be part an integral part of the database structure as opposed to a reporting tool– Integration is a must for responsive reporting (when you have
million of records to analyze)– Segmentation has to be easy to apply – could have thousands to
manage
Data Segmentation Example
• Data segmentation by “tagging” Call Detail Information• “Tag” assignment by multiple parameters, such as:
– Phone number digits (country code)– IP address (source and/or destination)– SS7 address (originating and/or destination point code)– VLAN Id
• Combine “tags” to capture multiple “views” of traffic
Automatic Notification of Service Level Issues
• Pro-active integration with “northbound” Network Management systems
• Both network and segmented data based alerts– Network-based addresses internal metrics– Segmentation-based alerts enable isolation to particular
interconnect, peering site, or Enterprise
• Alerts on both signalling and media metrics, such as:– Call Failure rates exceed 1.0% threshold– Average MOS falls below 3.0
SLA Benchmarking• Done by testing live network conditions
– For the network– Per interconnect partner / Enterprise
• Done for specific Key Performance Indicators, such as:– Average / Minimum MOS– Average / Maximum Post Dial Delay– Answer Seize Ratio
• Should be normative across network if possible
SLA Reporting• SLA verification via ongoing monitoring or
via periodic or on-demand testing– For the network– Per interconnect partner / Enterprise
• Trend analysis indicates potential problems or future areas for re-negotiation
VoIP Peering Example 1• Event: Carrier routing table update process fails to complete properly
• Problem: Standard network level alerts will not recognize this problem
• What service quality monitoring does:– Identification of abnormal traffic conditions – low call completion rates– Pro-active alert to Network Management System upon threshold violation– Ability to isolate problem to specific peering partner or peering sites
• Remediation: Re-routing of traffic to alternate carrier
• Net impact: Minimize or avoid customer service disruptions reduce churn minimize revenue loss
VoIP Peering Example 2• Event: SLA compliance dispute between carrier and customer
• Problem: Customer believes VoIP quality falls below agreed SLA
• What service quality monitoring does:– Analysis and reporting on quality measurements specific to customer– Accommodate multi-site, multi-country reporting– Trend analysis over time
• Remediation: Set up periodic capture specific quality metrics from customer sites, using SIP loopback or SIP VQ reporting capabilities
• Net impact: Minimize or avoid future customer disputes maximize revenue potential
Summary• Service Quality Monitoring is MUCH more
than just measurement
• Service Quality Monitoring provides the ability to perform SLA verification and reporting
• More accurate handling of SLAs means more valuable peer and customer relationships