VoIP Monitoring and Troubleshooting
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The document outlines the importance of VoIP monitoring as part of Unified Communications (UC) and UCaaS services, emphasizing the sensitivity of VoIP to network issues and the challenges in troubleshooting. It explains key concepts of VoIP technology, including SIP signaling and audio data transmission, while highlighting ThousandEyes' network intelligence platform for proactive monitoring of VoIP quality metrics across diverse infrastructures. Additionally, it details various use cases and testing methods to monitor VoIP performance, identify issues, and optimize quality of service.
VoIP Monitoring and Troubleshooting
- 1. 1© 2017 ThousandEyes Inc. All Rights Reserved.Confidential © 2017 ThousandEyes Inc. All Rights Reserved.
- 2. 2© 2017 ThousandEyes Inc. All Rights Reserved. About ThousandEyes Network Intelligence platform that gives you a complete picture from users to internal and cloud-based applications Surface insights from a global data set Lightweight, flexible data collection Unified view of diverse performance data Solve issues across shared infrastructure See any network like it’s your own
- 3. 3© 2017 ThousandEyes Inc. All Rights Reserved. VoIP Monitoring • VoIP Monitoring is critical because it is: • A key component of the UC and UCaaS suite of services • Very sensitive to network issues • Notoriously difficult to troubleshoot • Accelerated UCaaS adoption in the past two years • “Early adopter phase” -> “Early mainstream phase” • Increased reliance on the Internet and 3rd party infrastructure • Traditional voice monitoring is reactive and expensive • Based on call detail records (CDR) and packet capture (pcap) • Limited for benchmarking and planning scenario’s
- 4. 4© 2017 ThousandEyes Inc. All Rights Reserved. So how does VoIP work? • Session Initiation Protocol (SIP) • Pre-requisite for the voice call – RFC 3261: Standard protocol (however propriety versions exist to force vendor lock-down) – Application level protocol residing above TCP/IP stack – TCP or UDP – Text-based protocol like HTTP – Encrypted with TLS – Response Codes indicates the state of the request message Phase1: Signaling VoIP Phone A SIP Server/Proxy VoIP Phone B SIP RegisterSIP Register SIP INVITE 100 Trying SIP INVITE 180 Ringing 180 Ringing 200 OK 200 OK AUDIO CALL SIP BYE 200 OK SIP ACK SIP ACK SIP BYE 200 OK
- 5. 5© 2017 ThousandEyes Inc. All Rights Reserved. So how does VoIP work? Phase1: Signaling VoIP Phone A SIP Server/Proxy VoIP Phone B SIP RegisterSIP Register SIP INVITE 100 Trying SIP INVITE 180 Ringing 180 Ringing 200 OK 200 OK AUDIO CALL SIP BYE 200 OK SIP ACK SIP ACK SIP BYE 200 OK REGISTER INVITE CONNECT DISCONNECT
- 6. 6© 2017 ThousandEyes Inc. All Rights Reserved. • Real Transport Protocol (RTP) – Analog voice signals converted into data packets and sent over UDP – Audio frames are encapsulated in RTP packets – RTP packets are encapsulated in UDP packets – UDP packets are encapsulated in IP packets So how does VoIP work? Phase 2: Audio Data IP header UDP header Frame 1 RTP header Frame 2 Frame 3 RTP Audio Stream SIP Network
- 7. 7© 2017 ThousandEyes Inc. All Rights Reserved. • How voice traffic is encoded and decoded • Determines the quality of the VoIP conversation • G.711, G.722, SILK Key VoIP Concepts & Metrics • MoS • Latency • Jitter (De-Jitter buffer) • PDV Codecs QoS • Prioritization of VoIP Traffic • DSCP codes – Traffic shaping, firewall and LB configuration – 3 bits for class: Best effort, Assured Forwarding, Expedited Forwarding, Voice Admit VoIP Metrics
- 8. 8© 2017 ThousandEyes Inc. All Rights Reserved. Proactive VoIP Monitoring Monitor an end-to-end VoIP call Keep track of VoIP quality metrics Find QoS Changes Along the Path Measure SIP performance Audio Codec Used MoS Score Average of packet delays Packets dropped by the de-jitter buffer
- 9. 9© 2017 ThousandEyes Inc. All Rights Reserved. Key Use Cases • Regional expansion (new offices, call centers and locations) • Migration to UCaaS or hybrid solution • Network topology and routing • Capacity and utilization • Latency, jitter and loss • Infrastructure faults • Routing issues • QoS and DSCP values Pre-Deployment Post-Deployment
- 10. 10© 2017 ThousandEyes Inc. All Rights Reserved. How ThousandEyes Voice Tests Work 1 Monitor your on-prem/hosted server from Enterprise Agents in branch offices. RTP tests require agents on both ends of the call. For inter-office monitoring across the enterprise WAN simulate VoIP calls between Enterprise Agents in branch offices.
- 11. 11© 2017 ThousandEyes Inc. All Rights Reserved. How ThousandEyes Voice Tests Work 2 Monitor on-prem or hosted SIP server from Enterprise Agents in branch offices. RTP tests require agent on both ends of the call. Requires at least one Enterprise Agent. To understand performance to external locations, simulate VoIP calls between your offices and globally located Cloud Agents.
- 12. 12© 2017 ThousandEyes Inc. All Rights Reserved. How ThousandEyes Voice Tests Work 3 Monitor an end-to-end voice call through your UCaaS VoIP provider from both branch offices and external locations.
- 13. 13© 2017 ThousandEyes Inc. All Rights Reserved. • Monitor ONLY the SIP infrastructure from within the corporate network or global locations. • Supports TCP/UDP; SIP Options and SIP Register • SIP Metrics: Availability, Response Time, Total Time Choosing the Right Voice Test • Combines both SIP Server and RTP Stream tests • Closest to emulating end-user experience • For eg: Failed SIP INVITE from an agent will not trigger a RTP call SIP Server Voice Call • Simulate a RTP voice stream between two agents. • Requires at least one Enterprise Agent • RTP Metrics: MOS, Latency, Jitter, PDV RTP Stream
- 14. 14© 2017 ThousandEyes Inc. All Rights Reserved.© 2017 ThousandEyes Inc. All Rights Reserved. Demo
- 15. 15© 2017 ThousandEyes Inc. All Rights Reserved. Troubleshooting SIP Infrastructure Identify errors in SIP signaling phase SIP Metrics: Availability, Response Time, Total Time Monitor SIP infrastructure from your WAN or global vantage points Correlate SIP server availability to the network topology and characteristics
- 16. 16© 2017 ThousandEyes Inc. All Rights Reserved. Troubleshooting SIP Infrastructure Read SIP headers to diagnose issues
- 17. 17© 2017 ThousandEyes Inc. All Rights Reserved. Monitor VoIP Call Quality Identify issues in call quality by tracking key VoIP call quality metrics Dallas agent shows a drop in MOS score Identify SIP proxies in the path Voice calls combine both SIP signaling and RTP audio streams sequentially
- 18. 18© 2017 ThousandEyes Inc. All Rights Reserved. See what you’re missing. Watch the webinar: https://www.thousandeyes.com/resources/voip-webinar