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The challenges of VoLTE Service Monitoring

LTE rollouts supported by TEMS around the world

Ensure QoE

UnderstandScenarios

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Currently no accepted standard for measurement, monitoring VoLTE Services

Ascom has defined a formal definition, implementation strategy to help Operations Covers issues related to EPC, IMS, Application Service

We will describe this solution in a number of short articles

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UnderstandTest Scenarios

VoLTE Service Monitoring Challenges

TEMS™ VoLTE Service Monitoring: VoLTE Voice Call including passive signalling data analysis

The Agent: Software and Hardware layersTMM SW

agent

TMM HWagent

Test Suites

IMDN

CPIM

SMSoIP

L3 Radio

USSDoIP

L3 Radio

FEMTOCELL

L3 Radio

SIP Procedures

SIP

OMA DM

provisionXCAP

HTTP

TLS

IMS Procedures

RTP

AMR H.264MSRP

MEDIA Procedures

GSMA IR.92

(VoLTE)

GSMA IR.94

(Video over LTE)OMA SIMPLE OMA CPM

VoWiFiGSMA RCS

FEMTOCELL

Procedures

COM SERVER

(TMM) TEMS Monitor Master LTE ProceduresSRVCC

LAN adapter 2G/3G Modem 4G Modem

Test Cases

API Layer

Service Layer

Network Layer

Protocol Layer

Access Layer

PCC

Procs.

Gx App

Diameter

Base

Device/Client

Simulation

IPSec

Our Agents implement all these SW layers on top of a HW interface layer. By using an LTE modem to simulate a Smartphone we get optimum control, flexibility & low level access – and a proven architecture refined by thousands of hours of testing.

Emulated InterfaceInternal InterfaceMedia Path

TEMS Tracker: VoLTE to VoLTE calls

Element Service Metrics for MO and MT

Ascom TEMS Monitor MasterActive Agent

• Call setup preconditions• Call setup resources confirmation• Call setup alerting• Call setup answer• Audio exchange• Call release

• Call setup time• Audio POLQA score• Audio average jitter• Audio maximum jitter• Audio minimum bit rate• Audio average bit rate • Audio maximum bit rate• Audio packet loss rate

3rd PartyPassive Probe

• Collect signalling related S11, Gm, Gx and Rx network interfaces• Call trace

TEMS TrackerAnalysis of signalling collected by Passive Probing system

• Call Routing (User1, PCSCF1, PCRF1, PGW1, MME1)• MO and MT S11 LTE Tunnel Info• S11 GTP Failure Cause Code• S11 GTPv2 Qos info• Gx Auth Info• Gx Diameter Failure Cause Code• L1 and L2 audio SDP Info• L1 and L2 SIP Failure Cause Code• L1 and L2 SIP Reason Header• src audio RTP Info• dst audio RTP Info

• S11 GTPv2 Procedures• Create Bearer• Update Bearer• Delete Bearer

• Gx Diameter Procedures• Auth• Re-Auth• Credit Control

• L1 and L2 Call Start Time• L1 and L2 Call Ringing/Progress Tim• L1 and L2 Call Answer Time• L1 and L2 Call Answer Confirm Time• L1 and L2 Call End Tim

Ascom TEMS Monitor Master

IT Agent• Subscriber profile within HSS database• Subscriber profile within PCRF database

Analysis of Active Agent + Passive Signalling + Subscriber profile information

• Automated Root Cause of Failure Analysis

• Automated Service and Quality Degradation Analysis

Copyright 2016, Ascom Network Testing Ltd 8

The VoLTE Voice Call test caseThe Test Case Dashboard

• Service availability over time– when did the problem start?

• Service availability per step – where did the problem start?

Copyright 2016, Ascom Network Testing Ltd

Displays recent results for the selected (VoLTE Voice Call) test case:

• Quality Metrics over time – how well is the service operating?

• VoLTE to VoLTE service status by region on a world map

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The VoLTE Voice Call test caseThe Test Run Details dashboard

The Test Run Details dashboard displays details of a single test, including:

Copyright 2016, Ascom Network Testing Ltd

• Subscriber details: network operator, MSISDN, IMS and bearer

• Dependencies: the test cases run to support this test run: - LTE Attach, - IMS Entry Point Discovery, - IMS Registration and - IMS Subscription to Events

• Links: to Radio Trace, IP Trace, and Audio files to download

• Messages: information collected during this test run from a Passive Probe or CDR related to this scenario. Such as Audio Information, Call Routing, S11GTPv2 procedures, S11GTPv2-Route, S11GTPv2-QoS, S11GTPv2-Tunnel Info, …

• Root cause of failure: if there was an issue, an analysis of all the collected information designed to help identify what caused it.

• Test Case Flow: a diagram of the test case steps, showing the message flow and status of each step. See Signal Flow

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VoLTE Service Monitoring – Related posts

Articles:

• Day 1. VoLTE Service Monitoring

• Day 2. How critical is the VoLTE Service for my company?

• Day 3. New generation VoLTE Service Monitoring solution

• Day 4. I already monitor LTE, so I must be good for VoLTE?

• Day 5. Monitoring VoLTE Customer Experience

• Day 6. How can you uncover hidden areas of your VoLTE network and services to deliver the customer experience you really want?

• Day 7. VoLTE Customer Experience and Service Monitoring ... the perfect combination for an Active Monitoring strategy

• Day 8. VoLTE Multi-layer monitoring

Check the VoLTE Service Monitoring posts for links to subsequent articles.

Copyright 2016, Ascom Network Testing Ltd 16

VoLTE Service Monitoring – Related documents

TEMS VoLTE Service Monitoring solution:

1. A New Standard & the Test Cases Overview

2. Solution architecture & the VoLTE Voice Call test case

3. VoLTE Voice Call including passive signalling data analysis

Copyright 2016, Ascom Network Testing Ltd 16