ASCOM Myco 3 User manual

TROUBLESHOOTING GUIDE
Ascom Myco 3

TROUBLESHOOTING GUIDE
Ascom Myco 3
Trademarks
Ascom Myco™ is a trademark of Ascom (Sweden) AB.
Android ™, Google ™, Google play ™ and other marks are trademarks of Google LLC.
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TROUBLESHOOTING GUIDE
Ascom Myco 3
Abbreviations and Glossary
Abbreviations and Glossary
API Application Programming Interface
PCAP Packet CAPture
VoIP Voice over IP
RPCAP Remote Packet CAPture
WiFi Family of radio technologies that is commonly used for the wireless local area
networking (WLAN).
Used generically when referring to any type of 802.11 network.
WLAN Wireless Local Area Network
A type of LAN in which data is sent and received via high-frequency radio
waves rather than cables or wires.
VoWiFi Voice over WiFi
Refers to a system running VoIP over WLAN.
AP Access Point
BSS Basic Service Set
BSSID Basic Service Set Identifier
MDM Mobile Device Management.
DHCP Dynamic Host Configuration Protocol
A protocol for automating the configuration of computers that use TCP/IP.
DNS Domain Name Server
UDP User Datagram Protocol
TCP Transmission Control Protocol
IP Internet Protocol
Global standard that specifies the format of datagrams and the addressing
scheme. This is the principal communications protocol in the Internet Protocol
suite.
MAC Medium Access Control
In IEEE 802 LAN/MAN standards, the MAC sublayer is the layer that controls
the hardware responsible for interaction with the wired, optical or wireless
transmission medium.
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TROUBLESHOOTING GUIDE
Ascom Myco 3
SIP Session Initiation Protocol
SIP is a signaling protocol used for initiating, maintaining, and terminating real-
time sessions that include voice, video and messaging applications. SIP is
used for applications of Internet telephony for voice and video calls, in private
IP telephone systems, in instant messaging over IP networks, and in mobile
phone calling over LTE, Voice over LTE (VoLTE).
SSID Service Set Identifier
PBX Private Branch Exchange
A telephone system within an enterprise that switches calls between local
lines, and allows all users to share a certain number of external lines.
Also referred to as Call Manager.
PSTN Public Switched Telephone Network.
OSI Open Systems Interconnection
USB Universal Serial Bus: a serial bus standard to interface devices, for example
connect computer peripherals such as mice, keyboards, scanners etc.
RF Radio Frequency
DTIM Delivery Traffic Indication Message
NFC Near Field Communication
A set of communication protocols that enable two devices to establish
communication by bringing them within close proximity of each other.
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TROUBLESHOOTING GUIDE
Ascom Myco 3
Contents
1 Abo t This Doc ment ..................................................................................................................... 1
1.1 Target Group...................................................................................................................... 1
1.2 Prerequisites ...................................................................................................................... 1
1.3 Information Required by TAC ...............................................................................................2
2 Tro bleshooting Methodology........................................................................................................3
3 WLAN Overview.............................................................................................................................4
3.1 The Problem of Legacy WLANs ............................................................................................4
3.2 WLAN Planning and Provisioning..........................................................................................5
3.3 The Importance of Pre- and Post-Site Surveys........................................................................6
3.4 WLAN Dynamics .................................................................................................................6
3.5 Troubleshooting Implications and WLAN Design ....................................................................6
4 The Handset as a WLAN Wireless Client..........................................................................................8
4.1 VoWiFi Handset Protocol Layers...........................................................................................8
4.1.1 Troubleshooting the Layers ....................................................................................9
4.2 Voice Transmission over a VoWiFi System .......................................................................... 10
4.3 AP Scanning..................................................................................................................... 10
4.3.1 Active Scanning................................................................................................... 10
4.3.2 Passive Scanning................................................................................................. 10
4.3.3 Reconnect............................................................................................................ 11
4.3.4 Configured Channels and Scanning Intervals........................................................... 11
4.4 Power Save Mode.............................................................................................................. 11
4.5 Roaming............................................................................................................................ 11
4.5.1 Call Mode ........................................................................................................... 12
4.5.2 Scanning Algorithm.............................................................................................. 12
4.6 DFS Channel Probing ........................................................................................................ 12
4.7 Wi-Fi Configuration Recommendations.................................................................................13
5 Tro bleshooting Tools ................................................................................................................. 15
5.1 Site Survey Tools .............................................................................................................. 15
5.1.1 Wi-Fi Site Survey.................................................................................................. 16
5.1.2 Cellular Site Survey 1............................................................................................ 18
5.2 Protocol Analyzer Tools..................................................................................................... 19
5.3 Air Traces of 802.11 Traffic .................................................................................................20
5.4 Logging Scenarios ............................................................................................................ 21
5.5 Event Logs (Log Viewer) ....................................................................................................24
5.6 Debug with Timed Logging ................................................................................................26
5.7 Debug Using PCAP ..........................................................................................................28
5.8 Debug Using Remote PCAP...............................................................................................28
5.9 Export Logs with the Handset.............................................................................................29
5.10 Extract Log Files from the Handset .....................................................................................29
5.11 Diagnostics........................................................................................................................31
5.12 Perform a Factory Reset.....................................................................................................32
5.12.1 Factory Reset Using the Handset ..........................................................................32
5.12.2 Factory Reset via MDM.........................................................................................33
5.12.3 Hard Reset..........................................................................................................33
6 Tro bleshooting Scenarios...........................................................................................................35
6.1 Handset Errors..................................................................................................................35
6.1.1 System Related....................................................................................................35
6.1.2 Software Related .................................................................................................37
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TROUBLESHOOTING GUIDE
Ascom Myco 3
6.1.3 Hardware Related................................................................................................38
6.1.4 Installation and Maintenance.................................................................................43
6.2 WLAN Troubleshooting Scenarios ......................................................................................43
6.2.1 Voice Problems While Roaming.............................................................................43
6.3 Warning Messages............................................................................................................44
6.3.1 No Network Connection ......................................................................................44
6.3.2 No SIP Connection...............................................................................................47
6.3.3 Incorrect SIP Authorization Details.........................................................................48
6.3.4 No Phone Calls....................................................................................................49
7 Related Doc ments..................................................................................................................... 50
8 Doc ment History........................................................................................................................ 51
Appendix A Handset Parameters .....................................................................................................53
A.1 Article Numbers................................................................................................................53
A.2 Device Information ............................................................................................................53
Appendix B Ports............................................................................................................................55
B.1 SIP...................................................................................................................................55
B.2 Voice Traffic .....................................................................................................................55
B.3 Google Mobile Services.....................................................................................................55
B.4 Other Services..................................................................................................................55
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TROUBLESHOOTING GUIDE
Ascom Myco 3 About This Document
1 Abo t This Doc ment
This guide describes procedures to validate and perform troubleshooting for Ascom Myco 3 handsets. It
identifies some of the more common problem areas, and suggests approaches to troubleshooting and
investigating these problems. The guide contains detailed information about the behavior of the Ascom
Myco 3 under faulty or problematic conditions.
This version of the document provides troubleshooting procedures for Ascom Myco 3 devices running the
latest released software. Some information in this version of the document might be not applicable to the
earlier software releases, therefore it is recommended to use the latest software version (v2.X.X or later) to
get up-to-date information from this document.
This document describes features and settings for the following handset versions of Ascom Myco 3:
• Ascom Myco 3 Wi-Fi and Cellular
• Ascom Myco 3 Wi-Fi
• Ascom Myco 3 Wi-Fi and Cellular EU
• Ascom Myco 3 Wi-Fi EU
Ascom Myco 3 is referred to as the "handset" or the "device" in the manual, and can be specifically marked
with "Wi-Fi only" or "Cellular only" whenever the functionality differs between the handset versions.
1.1 Target Gro p
This document provides system administrators responsible for management and maintenance of Ascom
Myco 3 handsets with guidance about the types of problems that may occur during configuration and usage
of the devices. This guide explains the probable causes of these problems and suggests actions along with
a list of diagnostic and troubleshooting tools necessary to retrieve the existing issues.
This guide is also written with a focus on support network administrators responsible for troubleshooting
and supporting customer Voice over Wireless Fidelity (VoWiFi) systems, and the Wireless Local Area
Networks (WLANs) that support such systems. The guide may also be of considerable use to system
administrators and network planners intending to design, implement, deploy and commission a new WLAN
designed for VoWiFi access, or upgrade an existing WLAN to support a new VoWiFi system.
Many of the problems described in this guide arise because of poor provisioning and planning. In this
respect, system administrators and network planners are recommended to read the document Ascom
VoWiFi System, System planning, TD 93358EN.
1.2 Prereq isites
To gain the maximum benefit from this guide, readers should have the following:
Software
• The latest software version installed on the handset(s).
Knowledge and Experience
• How WLAN and Cellular networks function.
• Sufficient knowledge in networking concepts.
• A basic understanding of Voice over Internet Protocol (VoIP) and the VoIP Session Initiation Protocol (SIP).
• Have read Configuration Manual, Ascom Myco 3, TD 93309EN.
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About This Document
TROUBLESHOOTING GUIDE
Ascom Myco 3
• Have read other documents related to the installation, for example WLAN, or Cellular specification and
documents pertaining to the interoperability of the handset with the WLAN, or Cellular infrastructure.
1.3 Information Req ired by TAC
If an issue remains unresolved and a request needs to be opened with the Technical Assistance Centre
(TAC) team, different types of information and logs should be forwarded with regards to the area of
investigation.
Presented in the current section information includes but is not limited to the data required by TAC.
Additional information might be requested.
• The handset model.
• The handset software version (Firmware and Ascom Experience versions). For the details on the device
information, please refer to Appendix A Handset Parameters, page 53.
• The frequency of the occurrence of the error and information about how to reproduce the error, if
possible.
• A detailed description of the problem and what tests have been performed.
• The values of parameters that have been configured.
• The WLAN hardware and software versions of both controller and APs.
• If cellular version of the handset has been used, information about the cell phone provider should be
sent.
• If problems occur with Ascom Apps, for example Unite Axess app, information about the used Unite
software should be sent.
• Log files should be attached and appended with descriptions of the tests and equipment used in the
tests. For the detailed information on the types of logs that should be send, please refer to the 5.4
Logging Scenarios, page 21.
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TROUBLESHOOTING GUIDE
Ascom Myco 3 Troubleshooting Methodology
2 Tro bleshooting Methodology
There are many troubleshooting models that can be used by a support engineer. These methods might
vary but all of them are oriented towards defining and isolating problem areas. There is however usually a
general approach that applies to most situations.
This guide does not describe troubleshooting theories in details, rather than presents a suggested method
that has successfully been used.
A very common method is a cycle model as illustrated below:
Yes
Yes
Yes
No
No
No
Problem reported
3. Make hypothesis
Get support
2. What´s wrong?
What’s correct?
4. Prioritize where to start
5. Test and check
Apply known fix1. Get the picture
Problem
solved?
Stuck?
Familiar
problem?
Document the
solution
•Problem reporting. Define the nature of the problems that users experience and the circumstances in
which the problems arise. For example, VoWiFi problems usually involve interruptions in the audio
stream, disconnections, distortions such as echo and clicking noises, and delays. The user experiences
that small discrete parts of the conversation are missing.
•Get the picture. Elicit additional information from the user and try to picture the context and
circumstances in which the problem occurs.
•Ascertain what is working. At an early stage of the troubleshooting process it is of high importance to
rule out the devices that are functional. Why a handset is not functioning properly might depend on the
incorrect function of several other devices.
•Form a hypothesis. Make a list of possible causes. The fault is maybe on a device not primary a part of
the solution.
•Prioritize where to start. Eliminate causes that are quick to check first and do the more time-consuming
later. Also eliminate causes that make less impact for the users first. Remember that whatever action you
take may cause an interruption in the services. Make one change at a time and if problem is not solved
unroll your new changes. Document what changes were done.
•Test and check. Make sure the appropriate tools are available for testing a proposed solution. Do not
make unauthorized modifications.
An understanding of the above model can help in the troubleshooting process. A support engineer may use
the model and ask questions and gather facts and thereby identify a single device, location or application
that might be causing the problem.
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WLAN Overview
TROUBLESHOOTING GUIDE
Ascom Myco 3
3 WLAN Overview
A WLAN enables various devices, or WLAN clients, to communicate across Radio Frequency (RF) channels
through APs. APs provide RF coverage throughout the site covered by the WLAN and this enables users,
and their devices, to move around the site without being disconnected from the network. Each AP is
identified by a hard-coded MAC address.
Initially, WLANs were designed to allow users to send and receive data from devices such as laptop
computers but increasingly WLANs are being required to support different and more demanding types of
traffic such as voice and multimedia. A VoWiFi system is illustrated in Figure 1. VoWiFi Overview, page 4.
Figure 1. VoWiFi Overview
LAN
Handsets
Location Server
Controller
optional equipment
required equipment
AP
AP
IP-PBX
3.1 The Problem of Legacy WLANs
Legacy WLAN systems were designed for transmitting data packets; support for voice and other multimedia
was never envisaged when these systems were designed, deployed and commissioned. So many
traditional cell-based WLAN topologies proved unsuitable for handling channelization issues, AP-to-AP
handoffs, and the unpredictably of system bandwidth that are introduced when VoWiFi is implemented.
Voice is very susceptible to such issues being addressed satisfactorily. A WLAN that does not support
VoWiFi but is being upgraded to do therefore requires very careful planning, design, provisioning and
hardware deployment to get the level of performance to adequately support voice. These problems are
multiplied when different traffic types such as voice, video and data all contend for the same airspace.
Adding voice to a WLAN may require radical changes of the APs placement and the amount of APs needed.
If this is not considered feasible to undertake in a current installation VoWiFi may never perform as
expected.
It follows that if a legacy WLAN is to support VoWiFi then an assessment of how suitable the WLAN is to
support VoWiFi must be made. The number and deployment of additional devices involved in the WiFi
solution must be carefully assessed. For example, the assessment should consider the adequacy of the
current deployment in meeting cell boundary requirements because adequate cell overlap is a fundamental
requirement for a voice system. The assessment should conclude with a readiness report documenting the
suitability of the WLAN for both the wired and the wireless part of the network. The required parameter
settings of the devices supporting the WiFi system should also be documented.
The following table lists some of the topics that should be included in an assessment document:
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