Mitel MiVoice Business Voice Quality And Troubleshooting Manual
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Mitel MiVoice Business Voice Quality And Troubleshooting Manual

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Mitel MiVoice Business
VOICE QUALITY AND TROUBLESHOOTING GUIDE
Release 8.0

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Summary of Contents for Mitel MiVoice Business

  • Page 1 Mitel MiVoice Business VOICE QUALITY AND TROUBLESHOOTING GUIDE Release 8.0...
  • Page 2 The information is subject to change without notice and should not be construed in any way as a commitment by Mitel or any of its affiliates or subsidiaries. Mitel and its affiliates and subsidiaries assume no responsibility for any errors or omissions in this document. Revisions of this document or new editions of it may be issued to incorporate such changes.

  • Page 3: Table Of Contents

    Configuration Errors ............28 Configuration Errors on the MiVoice Business Platform and Gateways ....28...
  • Page 4 MCD Voice Quality Troubleshooting Guide General Guidelines ............28 VLANs .
  • Page 5 Mitel MiVoice Business Troubleshooting Guide ........
  • Page 6 MCD Voice Quality Troubleshooting Guide...

  • Page 7: Introduction

    VoIP quality, refer to the MiVoice Business Engineering Guidelines. AUDIENCE This guide is intended for use by Mitel certified MiVoice Business technicians and Mitel Product Support. Technicians who use this guide should be familiar with •...
  • Page 8 IP network, or after a new carrier was added? • Where does the problem originate? For example, does it originate in Mitel equipment or in another vendor’s customer premise equipment? •...

  • Page 9: Terminology

    You can then focus your troubleshooting efforts on the equipment in the call path. Analog Service Unit (ASU) An optional Mitel Networks hardware unit that connects analog sets and analog trunks to the system. Bandwidth Amount of data per unit time that can be transmitted over a network connection.
  • Page 10 Customer Premise Equipment (CPE) The telephone equipment on the customer site. On a Mitel customer site, the MiVoice Business system is the CPE. Incoming calls that arrive at the MiVoice Business system over the PSTN typically originate at CPE equipment located on the other side of the PSTN.
  • Page 11 LANs. A system of interconnected LANs is called a wide-area network (WAN). Network Service Unit (NSU) A Mitel hardware unit that connects T1 or E1 trunks to the Mitel system. Network Traffic Analyzer A computer application or hardware device that allows you to •...
  • Page 12 Voice Quality Troubleshooting Guide Table 1: Voice Quality Terminology TERM DEFINITION On Premise Station (ONS) Stations which are installed on the same premises as the PBX, or which can operate satisfactorily with the system when installed in adjacent premises without special circuit arrangements. Packet Delay The amount of time required for a packet to traverse the network.
  • Page 13 Note that in the context of this guide, no audio is not considered a voice quality issue because there is complete absence of voice. Refer to the MiVoice Business Troubleshooting Guide for situations in which there is no audio. Wide Area Network (WAN) A communication network that links across metropolitan, regional, or national boundaries.
  • Page 14 Wideband A wideband signal contains a larger range of frequencies than have traditionally been used to represent a signal. At Mitel, a wideband signal is one that is sampled at 16,000 samples per second and supports a frequency range of 100 Hz to 7200 Hz. This signal is...

  • Page 15: Analog, Tdm, Or Pstn Network Issues

    Note: Digital connections (PRI, BRI, T1, Mitel Digital sets and IP sets) are always 4-wire. Two-wire analog audio refers to two physical wires (normally a twisted pair) where both the transmit (TX) and the receive (RX) audio are carried over the same physical pair of wires.
  • Page 16 Voice Quality Troubleshooting Guide Figure 1: Reflection at a Hybrid Another possible, but less likely, cause of electrical reflection is crosstalk between transmit and receive analog audio wires. Crosstalk can originate in faulty telephone wiring at endpoints that use separate transmit and receive analog wires. Crosstalk is one of the factors that affects xDSL speeds.

  • Page 17: Where Does Electrical Echo Originate

    CPE on one side of the PSTN might be heard in the CPE on the other end. You must educate your customer so that they understand that although echo is being heard on a Mitel phone, the echo may in fact originate in another vendor’s CPE on the other side of the PSTN.

  • Page 18: Who Is Responsible For Correcting Echo

    Voice Quality Troubleshooting Guide Figure 2: Echo Originating in Customer Premise Equipment Echo in CPE can also be caused by reflections that originate in the Central Office Equipment of the Telco. Typically, reflection on the PSTN does not result in echo on PSTN calls because the call delay is usually too short.
  • Page 19 Scenario 1 In Scenario 1, a MiVoice IP Phone is connected via IP to the MiVoice Business platform which is connected to the PSTN via 2-wire, Loop Start (LS) trunk. Figure 3: Scenario 1 In Scenario 1 1.
  • Page 20 Scenario 2 In scenario 2, an analog phone is connected to the MiVoice Business platform via a 2-wire ONS line; the MiVoice Business platform is connected to the PSTN via 2-wire LS trunk.
  • Page 21 Analog, TDM, or PSTN Network Issues In Scenario 2: 1. With respect to reflection and echo, the PSTN treats the MiVoice Business LS trunk like a 2-wire analog phone. The hybrid on the Mitel LS trunk card generates a reflection into the PSTN network just like the reflection created at the hybrid in the 2-wire PSTN phone.
  • Page 22 Figure 5: Scenario 3 In Scenario 3: 1. The PSTN is not aware of the equipment used on the MiVoice Business side of the PRI interface. 2. If the MiVoice Business system introduces an echo causing delay in the IP path, you are responsible for preventing (cancelling) the echo from entering the PSTN.

  • Page 23: Echo Cancellers And Echo Suppressors

    Analog, TDM, or PSTN Network Issues ECHO CANCELLERS AND ECHO SUPPRESSORS The telecom industry has dealt with the problem of echo long before the introduction of VoIP technology. Satellite calls have echo because of the significant delay involved. Before Digital Signal Processing (DSP) technology, the way to eliminate echo was through the use of a device called an “echo suppressor.”...

  • Page 24: Causes Of Perceived Echo

    (double talk). The goal is to prevent both echo and choppy audio, but sometimes, the solution is to establish a balance between residual echo and choppiness. Echo Cancellers in the Mitel Communications Platform Echo cancellers are used in •...

  • Page 25: Cell Phones

    Analog, TDM, or PSTN Network Issues loud noise, or ringing. Essentially, this is another instance of double talk. Background noise can appear to the echo canceller as if someone were talking, thus causing the double-talk effect. ® This issue is more likely to occur on Bluetooth headsets.

  • Page 26: Signal Level Mismatches

    Voice Quality Troubleshooting Guide SIGNAL LEVEL MISMATCHES If the audio level from the far end is much lower than the transmitted audio level, the far end speech level may be close to the echo level. This causes the echo suppressor (NLP) to interpret the far-end speech as echo.

  • Page 27: Echo Basics Summary

    Echo that is caused by reflection on the long delay segment of non-Mitel equipment on the other side of the PSTN cannot be cancelled by Mitel equipment. The owner of the non-Mitel equipment is responsible for cancelling any echo that originates at their...

  • Page 28: Ip Network Issues

    Voice Quality Troubleshooting Guide IP NETWORK ISSUES Conditions that can result in voice quality issues on IP Networks include: • Latency (Delay) • Packet Loss • Excessive Speech Transcoding • Jitter • Lack of Bandwidth LIMITS FOR NETWORK ISSUES Table 3 provides recommended network limits for end-to-end delay, ping delay, packet loss, and jitter.

  • Page 29: Jitter

    Measure jitter using a network analyzer, or • Check the Average Jitter for the IP phone in the Voice Quality Statistics form of the MiVoice Business System Administration Tool (see “Voice Quality Statistics for MiVoice IP Phones” on page 63 for details).

  • Page 30: Packet Loss

    You can determine the Packet Loss at an IP phone in the Voice Quality Statistics form of the MiVoice Business System Administration Tool (see “Voice Quality Statistics for MiVoice IP Phones” on page 63 for details).

  • Page 31: Excessive Speech Transcoding

    • IP connection across an IP trunk route Compression affects other aspects of the MiVoice Business system as well. These include IP phones, the MiVoice Business platform, MiVoice Business devices, IP applications, IP networking routes and trunk routes, and licenses. Voice subjected to excessive compression or too many transcoding hops (for example, from G.711 standard to G.729.a and back to G.711)

  • Page 32: Lack Of Network Bandwidth

    Poor voice quality can result from a lack of network bandwidth. Ensure that there is sufficient bandwidth on the LAN and on the links to the WAN to support the amount of expected traffic. Refer to the MiVoice Business Engineering Guidelines for the LAN and WAN bandwidth requirements.

  • Page 33: Environmental Issues

    This issue is usually caused by interference from power cables that have been routed alongside the Ethernet cables that connect the MiVoice Business controller or layer 2 switch to the IP phone. This type of voltage interference affects the Ethernet cable run from the switch to the IP phone because the IP phone uses a floating ground.

  • Page 34: Configuration Errors

    CONFIGURATION ERRORS ON THE LAYER 2/3 SWITCHES AND ROUTERS The MiVoice Business platform layer 2 Switch, and the network layer 2 switches, layer 3 switches, and routers must be configured correctly to avoid voice quality issues. Follow the guidelines in this section.

  • Page 35: Vlans

    Ensure that the packet per second (PPS) rate of routers and switches is adequate for the amount of voice traffic.  Set the router Maximum Transmission Units (MTU) value to divide larger packets into smaller packets, especially for slower speed links (anything less than T1 rates). See the MiVoice Business Engineering Guidelines for details.

  • Page 36: Lan Quality Of Service Policies

    The MiVoice Business platform can apply different LAN QoS policies to voice packets, signaling packets and other packets. Use the LAN Policy (QoS) form in the MiVoice Business System Administration Tool to set the LAN QoS policy values. In a Cisco-based environment the recommended settings are: ...

  • Page 37: Troubleshooting Voice Quality

    Troubleshooting Voice Quality TROUBLESHOOTING VOICE QUALITY METHODOLOGY When troubleshooting voice quality issues, follow the steps listed below: 1. Record site information (contact details, hardware and software, ARS information). 2. Collect problem details and list affected devices. 3. Create a detailed network diagram. 4.

  • Page 38: Hardware And Software Information

    HARDWARE AND SOFTWARE INFORMATION Use the following table to record the • Site hardware platforms (for example, MiVoice Business platforms, MiVoice Business gate- ways, Analog Service Units, peripheral nodes) • Software versions (for example, MCD Release 4.2) running on each platform.
  • Page 39 Troubleshooting Voice Quality Table 7: Collecting Problem Details VOICE QUALITY QUESTIONS PROBLEM DETAILS  What is the nature of the problem? Buzzing  Choppy voice  Clipped voice (truncated words) Tip: You can find sample audio recordings  Clipped voice (overdriven or distorted) of some of these voice quality issues on the internet at the following URL: ...
  • Page 40 Voice Quality Troubleshooting Guide Table 7: Collecting Problem Details VOICE QUALITY QUESTIONS PROBLEM DETAILS  Is it loud or soft? Loud  Soft  Varies from loud to soft  None (no volume issues)  Is the problem constant or intermittent? Constant ...
  • Page 41 Digital Enhanced Cordless Telecommunications (DECT)  IP DECT  Conference  Teleworker  Mitel MiCollab Audio, Web, and Video Conferencing  MItel MiCollab Client  All types  Is there a specific type of call destination Local associated with the problem? ...
  • Page 42 Voice Quality Troubleshooting Guide Use the following table to list the devices affected. Table 8: Affected Devices LOCAL OR VOLUME DEVICE EXTENSIO CALL LONG (LOUD OR TYPE TYPE TRUNK ID SYMPTOM DATE/TIME DISTANCE SOFT) 5330 IP 5001 External Constant May 5, 2011 Long Loud Only...

  • Page 43: Create A Detailed Network Diagram

    • Communication Platforms: Identify the number and type of communication platforms (for example: MiVoice Business Virtual, MiVoice Business Multi-instance, MiVoice Business for Industry Standard Servers, MXe, CX/CXi, AX controllers). If the system is resilient, identify the primary and secondary controllers.
  • Page 44 Voice Quality Troubleshooting Guide...

  • Page 45: Isolate The Issue

    Troubleshooting Voice Quality ISOLATE THE ISSUE Isolate the voice quality issue to a specific component (for example, IP phone, analog phone, controller, switch, or router) or to an area of the network (for example, ONS line, analog trunks, WAN, LAN, subnet, or vLAN) by placing calls to destinations that use different paths through the network.
  • Page 46 Voice Quality Troubleshooting Guide...
  • Page 47 IP Trunk Calls?  on a single IP trunk  on calls on the same MiVoice Business platform  on calls across a specific MiVoice Business trunking gateway  between the main and satellite office  across the WAN ...

  • Page 48: Troubleshooting Charts

    Quality of Service settings. on all network components (MiVoice calls, or IP phone calls Business platforms, layer 2 switches, layer 3 across TDM. switches, routers, and VLANs). Refer to the MiVoice Business Engineering Guidelines for QoS guidelines. Page 1 of 2...
  • Page 49 Configure Bandwidth Management zones. latency is most likely occurring in the calls across TDM Refer to the MiVoice Business Engineering VoIP network, either in the Mitel IP Guidelines and System Administration Tool system, or on the CPE VoIP system on online help for details.

  • Page 50: Hissing, Buzzing, Hum, Motor Boating

    PSTN. end. See “Identifying the Source of Echo” on phones when calling a page 55 for instructions. Inform customer specific external that this issue is not being caused by Mitel destination or remote equipment. office. Multiple analog and IP Echo is originating at cell phone or Bluetooth device.

  • Page 51: Crackling, Clicking, Popping, Or Static

    All calls involving a Ethernet cable that connects IP Phone to Route Ethernet cables separately away from MiVoice Business controller or layer 2 any power cables. Refer to the MiVoice single IP phone switch is routed in close proximity to Business Hardware Technical Manual for power conductors.
  • Page 52 Ensure Quality of Service settings are to incorrect Quality of Service settings correct on all network components (MiVoice phones on a specific on MiVoice Business platform, layer 2 Business platforms, layer 2 switches, layer 3 MiVoice Business switch, layer 3 switch, or router.

  • Page 53: Choppy Voice

    Note: Use the following tools to evaluate bandwidth on the network: - “Network Traffic Analyzer” on page 59 - “Voice Quality Statistics for MiVoice IP Phones” on page 63 - “VoIP Bandwidth Management on MiVoice Business Platforms” on page 60 - “Ping Test” on page 62...

  • Page 54: Clipping (Truncating During Double-Talk)

    (MiVoice Business platforms, layer 2 MiVoice Business switches, layer 3 switches, routers, and platform, layer 2 VLANs). Refer to the MiVoice Business switch, layer 3 switch, Engineering Guidelines for QoS or router. guidelines. Calls involving...

  • Page 55: Garbled Voice, Poor Intelligibility, Or Distortion

    CORRECTIVE ACTION Calls involving IP Packet loss due to lack of network Configure Bandwidth Management zones. bandwidth between network components Refer to the MiVoice Business Engineering phones on LAN or (MiVoice Business platforms, layer 2 Guidelines and System Administration Tool WAN.

  • Page 56: Distorted Music On-Hold

    Multiple calls involving TDM fabric (switching matrix) is faulty. Replace ASU, AMB, or AOB. Refer to the MiVoice Business Technician’s Handbook for analog phones on the instructions on how to replace an AMB or same Analog Service AOB.

  • Page 57: Dropped Calls

    WAN. Bandwidth Management and Call Check Bandwidth Management zone Admission Control is configured configuration. Refer to the MiVoice Business incorrectly. Engineering Guidelines and System Administration Tool online help for details. Packet loss or bit errors occurring due Ensure Quality of Service settings are correct...

  • Page 58: Tinny Audio (Drain Pipe)

    Access the Configuration (Debug) Menu on Phone. the phone to view its settings and network parameters, including its Gateway IP address (refer to the MiVoice Business Troubleshooting Guide for instructions). Silence occurs during IT administrator was performing Perform router maintenance after business maintenance on routers during an IP phone call.

  • Page 59: Delayed Response Time (Citizen's Band Effect)

    MiVoice Business Engineering Guidelines. Configure Bandwidth Management zones. Refer to the MiVoice Business Engineering Guidelines and System Administration Tool online help for details. Packet loss or bit errors occurring due Ensure Quality of Service settings are correct to incorrect Quality of Service settings.

  • Page 60: Low Or High Audio

    56) to apply correct settings. trunks Incorrect Loss/Level plan is selected on The Loss/Level plan is determined by the MiVoice Business platform. Country setting in the Licensing and Options Selection form of the MiVoice Business platform. Ensure that the Country setting is correct.

  • Page 61: Using Tests And Diagnostic Tools

    If necessary, you can use the tests and diagnostic tools described in this section to collect additional data on specific voice quality issues. IDENTIFYING THE SOURCE OF ECHO It is normal to receive reflection on a call from the PSTN to a phone on the MiVoice Business system. •...

  • Page 62: Line Measurement Tool

     determined if all LS trunks are from the same CO. For loopback, tests must be performed on LS trunks that are provided from the same CO into the MiVoice Business system.  established a connection between the LS trunk line on the AX Controller card chassis, Analog Main Board, Analog Option Board, or ASU II and the local CO.

  • Page 63: Configure System For Testing Using Central Office Numbers

    You can also run the Line Loss Level test on an LS trunk by setting up loopback through another LS trunk on the MiVoice Business system. You must program the trunks and designate one of the trunks as an answer point for the milliwatt tone.

  • Page 64: Individual Or Batch Line Quality Test

    This test takes approximately 15 minutes to complete on each trunk. While the test is running on a trunk, the system takes the trunk out of service. CAUTION: Only run this test at the request of Mitel Technical Support. System performance could be degraded while the test is running.

  • Page 65: Voice Over Ip Troubleshooting Web Site

    • detect VoIP calls in the captured data • verify Quality of Service settings on the MiVoice Business platform, layer 2 Switches, and routers • listen to problematic calls. Note: Before using a network traffic analyzer, such as Wireshark, ensure that you disable voice encryption in the System Options Assignment form of the MiVoice Business System Administration Tool.

  • Page 66: Handset Audio Tap

    Quality issues on VoIP calls can be caused by a lack of bandwidth. The Bandwidth Management feature in the MiVoice Business platform allows you to track and manage bandwidth consumption by the VoIP media streams. The bandwidth used by the media stream is measured between zones of co-located IP phones.

  • Page 67: Tracert Maintenance Command

    WAN, you may need to upgrade your service. TRACERT MAINTENANCE COMMAND This MiVoice Business System Maintenance Command traces the path • from the Real Time Complex card in the MiVoice Business platform to a destination IP address, or • from IP sets to a destination IP address.

  • Page 68: Ping Test

    You can use a ping utility to determine the round-trip delay between devices on the network. MIVOICE BUSINESS SYSTEM ADMINISTRATION TOOL PING UTILITY The IP Telephones form in the MiVoice Business System Administration tool provides a ping utility that you can use to determine whether a programmed, in-service IP telephone is accessible.

  • Page 69: Voice Quality Statistics For Mivoice Ip Phones

    You can view jitter, packet loss, and latency (delay) statistics for MiVoice IP Phones in the Voice Quality Statistics form in the MiVoice Business System Administration Tool. The form also lists other useful information such as the device type of the endpoint, the last CODEC used in the call, the IP address of the subnet and the IP address of the endpoint.
  • Page 70 5560 IPT (Master and slave devices are displayed separately), 5215 dual mode 5212, 6920, 6930, 6940. Refer to the System Administration Tool online help for the most up-to-date list of supported phones. Note that SIP phones, including Mitel SIP phones, do not support Voice Quality Statistics.

  • Page 71: System Diagnostic Reports

    View Logs File page. These logs can be used by Mitel Product Support to isolate and troubleshoot voice quality issues that are caused by resource shortages in the virtual environment.

  • Page 72: Station Message Detail Recording (Smdr) Logs

    Voice Quality Troubleshooting Guide STATION MESSAGE DETAIL RECORDING (SMDR) LOGS Review the MiVoice Business System Administration Tool SMDR call logs for information on problem calls: • call start time • calling party • called party • call duration • digits dialed (maximum 26 digits) •...

  • Page 73: Appendix: Additional Self-Help Resources

    To access the Online Service Desk: 1. Log into Mitel OnLine. 2. From Mitel OnLine, click Support, then click Online Service Desk. The first time you log in you will be asked for your company’s Technical Support ID. 3. Choose your channel partner location.

  • Page 74: Checking For Fixes In Software Patches

    6. Display a summary of your technical credits (depending on your access privileges). 7. Ensure that you enable your profile to allow Mitel to notify you via email when your ticket is updated.

  • Page 75: Fixed In Software Update

    To determine if a problem has been fixed in a minor software update: 1. Log into Mitel OnLine. 2. From Mitel OnLine, click Technical, and then click Knowledge Base. 3. Select the product name (for example, 3300 Integrated Communications Platform).
  • Page 76 Voice Quality Troubleshooting Guide...

  • Page 77: Index

    Index Index Configuration errors 28 on MiVoice Business and gateways 28 switches and routers 28 Contact details, for site 31 Acoustic echo CPE, definition 4 description 10 Crackling, troubleshooting 45 troubleshooting 43 Crosstalk ADSP 21161 56 definition 3 Analog Service Unit, definition 3...
  • Page 78 G.711 standard 25 G.722.2 standard 25 G.729a standard 25 Garbled voice, troubleshooting 49 Methodology, for troubleshooting 31 Gateway errors 28 Mitel knowledge base 67 MiVoice Business platform errors 28 system diagnostics 65 Handset audio tap troubleshooting guide 67 definition 4...
  • Page 79 Index crackling, clicking, popping, static 45 crosstalk 50 Recording delayed response time 53 hardware and software info 32 distorted music on hold 50 site information 31 dropped calls 51 Reflection echo 42 and delay 11 electrical echo 42 definition 6 garbled voice or distortion 49 Registering, for technical support services 68 hissing, buzzing, hum, motor boating 44...
  • Page 80 Voice Quality Troubleshooting Guide...

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