Basic troubleshooting for Askozia IP PBX phone systems - webinar 2016, English

•

1 like•841 views

In this webinar, we have a look at typical issues related to VoIP telephony and IP PBX. We introduce introduce SIP traces and explain how to create them and for which scenarios they are useful. Furthermore, we discuss typical caller ID problems and how to target them, as well as basic debugging for beroNet gateways and interface cards.

Agenda
Basic Troubleshooting
•Introducing SIP traces
•Tips and tricks for caller ID debugging
•Basic beroNet troubleshooting

Introducing SIP traces
What issues require a trace?
-
•phones are not ringing
•the wrong phone rings
•calls are being dropped
•provider do not register
•calls can not be made

Introducing SIP traces
How to create a trace?
•create a SSH connection
•password is equal to the web GUI
ssh root@[system’s.IP.address]

Introducing SIP traces
How to create a trace?
•enter Asterisk console
asterisk -r

Introducing SIP traces
How to create a trace?
•increase the log level
core set debug 3
core set verbose 3
sip set debug on

Introducing SIP traces
How to create a trace?
•recreate the issue

Introducing SIP traces
How to create a trace?

Introducing SIP traces
How to create a trace?
•after tracing: decrease log level
sip set debug oﬀ
core set debug 0
core set verbose 0

Introducing SIP traces
And if I use Windows?
•Use PuTTY
•establishSSH connection
•in the console, use the known commands
•WIKI.ASKOZIA.COM
•ASKOZIA PBX -> Help for integrators -> 17 SIP
traces

Tips for CallerIDs
Typical issues with Caller IDs
•Wrong Caller ID is sent when calling out
•Calls are getting blocked by the provider
•Wrong caller ID is sent to another phone, while transferring
•Wrong caller ID is sent to another phone, while forwarding
•Caller ID does not get matched with phonebook

Tips for Caller IDs
The correct format
•national
•international
•E.164
•without area code
•only extension
incoming
outgoing

Tips for Caller IDs
SIP Headers
Telephone account - advanced options
Provider account - advanced options

Tips for CallerIDs
Manual Dialplans
Provider account - advanced options
Telephone account - advanced options

Tips for CallerIDs
The right provider
•If possible, use providers where conﬁguration templates are available
•Always use providers with good documentation for Asterisk
•When forwarding, always make sure, CLIP NO SCREENING is activated

beroNet cards
Active interface cards and gateways

beroNet gateways
How to enter the web interface
Unix based:
ssh root@[IP.of.the.system] -L8888:10.1.0.2:80
Windows:
Use Putty
wiki.askozia.com->AskoziaPBX-Help for
Integrators-> 14 Access beroNet

beroNet gateways
Inside the web interface
User: admin
Password: admin

beroNet gateways
Inside the web interface
Uplink states of all the ports

beroNet gateways
Inside the web interface
Hardware conﬁguration

beroNet gateways
Inside the web interface
Dialplans

beroNet gateways
Inside the web interface
ISDN dialplan debugging

Questions?
Time to wake up!
markus.ehlers@askozia.com

This document discusses setting up a VPN for connecting external phones securely. It recommends using a VPN over SIP port forwarding due to vulnerabilities with open ports. A VPN encrypts traffic so metadata and calls cannot be intercepted. It also presents like the phone is on the local network, avoiding issues with networks or firewalls. The document then provides instructions for configuring an OpenVPN server on pfSense and Snom phones as clients to implement this VPN solution.

Saxon_TeacherWorkSample

Adam Saxon

This unit on the Industrial Revolution was taught to two 11th grade U.S. History classes with mostly English language learners. Pre- and post-assessments showed that students' understanding improved over the course of the unit. The teacher had to make adjustments such as providing guided notes and structuring groups to support student learning. Analysis of assessment results indicated that all students improved, with the largest gains made by those who started with lower scores. This demonstrates that the instruction was effective at helping students grasp key concepts.

Rod Rimando - Opportunities for advanced robotics in nuclear cleanup

Daniel Huber

This document discusses the U.S. Department of Energy's Environmental Management (EM) mission to clean up legacy waste from nuclear weapons production and research dating back to the Manhattan Project. EM oversees cleanup at 16 major sites around the country with an estimated remaining cost of $235 billion to complete by 2065. The document outlines EM's interest in using robotics and remote systems to improve worker safety, efficiency, and performance for hazardous cleanup tasks including decontamination, demolition, inspections of underground storage tanks and tunnels, and handling of radioactive and hazardous materials. It also discusses various operating domains where robotics could be applied, such as gloveboxes, hot cells, underground facilities, underwater locations, and aerial inspections.

How to set up emergency numbers in AskoziaPBX - webinar 2016, English

Askozia

Hotel_Bepoz

Trina Hill

This document summarizes the services and features provided by Bepoz POS for hotel and club businesses. It highlights key offerings such as 24/7 support, mobility access for staff and customers, integrated marketing and loyalty tools, real-time reporting and alerts, and flexible financing options with no upfront software costs. The goal is to provide an effective POS solution and service to help businesses run smoothly.

027_Business_Brochure_LR

Enda Conboy

This document outlines the pricing plans for a mobile service provider, listing the monthly access charge, monthly cost per mobile, and bundle details for each plan. The plans range from €70 to €950 per month and include an increasing number of minutes, texts, and data, along with rates for charges incurred after exceeding the bundle amounts. The most expensive plan provides up to 12,000 minutes, 35,000 texts, and 35,000MB of data.

Social psychology

Tengku Syakira

Pusheen, a female office cat, is pushed to work overnight preparing for a last-minute presentation. Due to her rushed preparation and unkempt appearance, Pusheen does poorly in her presentation and is ridiculed by her coworkers. Overcome with frustration, Pusheen quits her job and becomes a stripper, hoping to find a career where women are appreciated. The comic explores the social psychology concepts of extrinsic motivation, the looking-glass self, sexism, displaced aggression, and self-fulfilling prophecies through Pusheen's experiences.

Este documento describe los 10 pasos para instalar SQL Server 2014 de manera sencilla. Inicialmente se registra como estudiante en DreamSpark para descargar el software. Luego se selecciona la versión adecuada para el sistema y se especifica la carpeta de destino. Finalmente, se completa el proceso de instalación y configuración, asegurándose de cambiar el idioma a español para evitar problemas durante la instalación.

Audience feedback

Lily Young

The document summarizes audience feedback on a music video. Viewers liked the black and white cinematography, camera work, editing, and how it fit the song. They found the video convincing because it was filmed and cut well and matched the mood and message of the music. Some criticisms were that the artist didn't look like they were singing and there was too much repetitive walking. Based on this feedback, the creators concluded they should improve the lip syncing and add more scenes related to the train to make the story clearer and video more engaging.

Waterford Steel Brochure 2004

Enda Conboy

This document provides information on various Waterford range cooker models, including their dimensions, features, functions and optional accessories. It describes dual fuel and electric single and twin oven models ranging from 60 to 120cm, with various hotplate configurations. Specifications include oven types, electrical requirements, and trim/colour options. An accessories section lists extra items like griddles, hoods and cleaning kits that can enhance the cooking experience.

CURRICULUM VITAE OF AG JOOSTEAdbill jooste

Innovation - in a business development perspective (and own biotech experience)

Hans Eibe Sørensen

Innovation is simple, but often misunderstood. In plain terms: Innovation = Invention/idea + Commercialization. What most tend to forget it that the commercialization part is the tricky one. I gave this presentation to 200+ natural science students today. They are the future and should learn - up front - about the frequently occurring misconceptions on innovation in industry and academia alike. Enjoy the ride! Hans Eibe

Situations(2)

Erkebulan Ermek

CV_Ranka_Papic_eng

Ranka Papić

Ranka Papić has over 15 years of experience in banking, starting as a Data Verification Officer and progressing to roles with increasing responsibility such as Telecollection Officer, Senior Administration Collection Officer, Organization and Process Specialist, and Senior Organization and Process Specialist. She has a degree in Management from the Faculty of Organizational Sciences in Belgrade and is proficient in English, Microsoft Office, Visio, Adonis, Lotus Notes, and proprietary banking software.

Huelva powerpoint rosa

Rosa Fernandes

El documento describe varios monumentos, iglesias y lugares históricos de la ciudad de Huelva, España. Entre ellos se encuentran la estatua de Cristóbal Colón, el Monumento a la Fe Descubridora, el Monumento Virgen del Rocío, el Convento Hermanas de la Cruz, la Iglesia de San Sebastián, la Iglesia del Sagrado Corazón, el Puerto, la Plaza de Toros de La Merced, la Casa Colón, la Plaza de las Monjas, el Estadio Nuevo Colombino y el Parque Moret. El document

Produccion y desarrollo sustentable

andalonjr

El documento proporciona información sobre cómo prevenir y responder a diferentes desastres naturales como inundaciones, huracanes, incendios, erupciones volcánicas y terremotos. Explica las características de cada fenómeno y recomienda acciones como evacuar zonas de riesgo, mantenerse informado, cerrar puertas y ventanas para evitar la propagación de fuego o humo, y alejarse de árboles, postes y cables durante tormentas. El objetivo es crear conciencia sobre estos eventos y promover la seg

Mini canvas

autoa app

PIB 3er trimestre 2015

Afines, Asesoría en Finanzas y Eficiencia S.A.

El documento describe el desempeño de la economía ecuatoriana hasta el tercer trimestre de 2015, notando un menor dinamismo generalizado en la producción y el crecimiento. La mayoría de los sectores experimentaron contracciones trimestre a trimestre, incluidos la construcción, la industria, el comercio y la producción petrolera. Solo unos pocos subsectores como la acuicultura y los servicios profesionales evitaron este comportamiento a la baja. El documento atribuye este desempeño más débil a factores tanto de oferta como de demanda.

Inflación Diciembre 2015

Afines, Asesoría en Finanzas y Eficiencia S.A.

Rapidly variying flow

Milan Sheta

This document summarizes rapidly varying flow, which refers to significant changes in water depth over a short distance. It occurs where there is a disturbance to the balance between gravity and friction, such as at a weir. There is often a transition between deep, slow flow and shallow, fast flow. For a smooth transition, the total head is assumed constant, while an abrupt transition like a hydraulic jump can cause head loss. A hydraulic jump is an abrupt change from shallow, fast flow to deep, slow flow and occurs when upstream and downstream conditions impose different water depths. Mass is conserved across it, while energy is lost mostly as heat.

Balantzea enpresa

autoa app

Digital Signatures: how it's done in PDF

iText Group nv

These are the slides that were be presented at a GlobalSign customer event in Leuven on September 16, 2014. In my talk, I explained why digital signatures are important. I introduced the audience to the basic concepts used when signing documents and showed how these concepts are used in the context of PDF. Furthermore, I discussed different architectures to implement a digital signature solution, as well as how digital signatures can be used in a workflow and how we can create digital signatures for the long term.

SIP trunking in Janus @ Kamailio World 2024

Lorenzo Miniero

Green Code Lab Challenge 2015 Subject Details

Olivier Philippot

1) The document provides information about the Green Code Lab Challenge 2015, including important dates and deadlines, an overview of the challenge topics and goals, and details about the evaluation criteria and infrastructure provided. 2) Participants will develop an application to efficiently collect and transmit IoT sensor data from a Raspberry Pi to a server, and their solutions will be evaluated based on power efficiency, network use, best practices sharing, and justification of coding choices. 3) The challenge will run continuously for 48 hours, with solutions evaluated every 15 minutes on the criteria and teams ranked on a 1000 point scale, and failure to meet requirements like providing code by the deadline could result in elimination.

Hacktrikz - Introduction to Information Security & Ethical Hacking

Ravi Sankar

Defcon 21-ozavci-vo ip-wars-return-of-the-sip by pseudor00t

pseudor00t overflow

This document discusses vulnerabilities in VoIP networks that use SIP (Session Initiation Protocol). It describes how an attacker could use automated tools like the Viproy VoIP Penetration Testing Kit to discover SIP services, brute force credentials, spoof calls, bypass billing and CDR systems, launch denial of service attacks, and abuse trust relationships between SIP servers and gateways. The document cautions that while administrators may think their VoIP networks are isolated and secure, basic attacks are actually quite easy to carry out with the right tools.

How to protect your business telephony from cyber attacks - webinar 2017, Eng...

Askozia

Voice-over-IP (VoIP) provides many new features over PSTN. However, the interconnection with your IT infrastructure also carries risks affecting the security and integrity of your IP services. As IT networks are targeted by attackers, insufficient prevention can endanger not only your network but your telecommunication infrastructure that is build on top of it. This paper aims to educate about possible risks, common attacks and how to prevent them from being successful.

authentication.ppt

AchinikeWinifred

The document discusses authentication mechanisms including: 1) Password authentication using hash functions and salts to securely store passwords without revealing the actual passwords. 2) Challenge-response authentication protocols that use nonces and encryption to prove a user's identity without risking playback attacks. 3) Biometric authentication using unique physical traits but with limitations around reliability, cost, and privacy. 4) Token-based authentication using devices like smart cards that provide cryptographic challenges to prove possession of credentials. It also covers distributed authentication systems using trusted intermediaries like Kerberos' key distribution center (KDC) to enable secure shared secret key establishment, and certificate authorities (CAs) to validate public keys are associated with

Asterisk Complete Training

Flavio Eduardo de Andrade Goncalves

This document provides an overview and objectives for an E-Learning training course on building a complete PBX with Asterisk. The training will cover understanding and installing Asterisk, building a simple PBX with SIP phones and SIP trunks, configuring features like dialplans, IVRs and voicemail, and integrating applications. By the end of the course, students will have hands-on experience building their own basic Asterisk system. Various chapters include objectives, presentations on topics, and instructions for labs to gain practical experience configuring Asterisk.

Viewers also liked

Instalación de sql server 2014

Nadia RC

Audience feedback

Lily Young

Waterford Steel Brochure 2004

Enda Conboy

CURRICULUM VITAE OF AG JOOSTEAdbill jooste

Innovation - in a business development perspective (and own biotech experience)

Hans Eibe Sørensen

Situations(2)

Erkebulan Ermek

CV_Ranka_Papic_eng

Ranka Papić

Huelva powerpoint rosa

Rosa Fernandes

Produccion y desarrollo sustentable

andalonjr

Mini canvas

autoa app

PIB 3er trimestre 2015

Afines, Asesoría en Finanzas y Eficiencia S.A.

Inflación Diciembre 2015

Afines, Asesoría en Finanzas y Eficiencia S.A.

Rapidly variying flow

Milan Sheta

Balantzea enpresa

autoa app

Viewers also liked (14)

Instalación de sql server 2014

Audience feedback

Waterford Steel Brochure 2004

CURRICULUM VITAE OF AG JOOSTE

Innovation - in a business development perspective (and own biotech experience)

Situations(2)

CV_Ranka_Papic_eng

Huelva powerpoint rosa

Produccion y desarrollo sustentable

Mini canvas

PIB 3er trimestre 2015

Inflación Diciembre 2015

Rapidly variying flow

Balantzea enpresa

Similar to Basic troubleshooting for Askozia IP PBX phone systems - webinar 2016, English

Digital Signatures: how it's done in PDF

iText Group nv

SIP trunking in Janus @ Kamailio World 2024

Lorenzo Miniero

Green Code Lab Challenge 2015 Subject Details

Olivier Philippot

Hacktrikz - Introduction to Information Security & Ethical Hacking

Ravi Sankar

Defcon 21-ozavci-vo ip-wars-return-of-the-sip by pseudor00t

pseudor00t overflow

How to protect your business telephony from cyber attacks - webinar 2017, Eng...

Askozia

authentication.ppt

AchinikeWinifred

Asterisk Complete Training

Flavio Eduardo de Andrade Goncalves

BlackHat Hacking - Hacking VoIP.

Sumutiu Marius

This document summarizes a presentation on hacking VoIP systems. It begins with introductions of the presenters and an overview of VoIP security risks. The agenda is then outlined, covering footprinting, scanning, and enumerating VoIP systems to obtain information. Techniques for exploiting the underlying network through man-in-the-middle attacks and eavesdropping are discussed. Finally, exploiting VoIP applications through fuzzing, denial of service, and signaling manipulation will be covered.

Sounds Like Botnet

Itzik Kotler

VoIP is one of the most widely-used technologies among businesses and, increasingly, in households. It represents a combination of Internet technology and phone technology that enhances and expands the possibilities of both. One of these possibilities involves using it for botnet command and control infrastructure and a data exfiltration vector. The concept of VoIP Botnet is to operate in closed networks with limited access and the potential of censorship using everyday telecommunication and telephony services such as voicemail, conference calls, voice and signaling information. Moshi Moshi is a proof of concept VoIP Botnet that allows the operator to dial in from a pay phone or mobile phone, and get shell access and exfiltrate data from the bots. This presentation will discuss and demonstrate the use of VoIP technology to create "Moshi Moshi," we also explore some interesting properties of VoIP based botnet. Additionally, we will discuss mitigating factors and ways that VoIP providers should implement in order to prevent further VoIP abuse.

[2011 CodeEngn Conference 05] Deok9 - DBI(Dynamic Binary Instrumentation)를 이용...

GangSeok Lee

2011 CodeEngn Conference 05 DBI 란 Dynamic Binary Instrumentation 의 약자이다. 이는 실행 중인 어떤 Process 또는 Program 에 특수한 목적으로 사용될 임의의 코드를 삽입하는 방법이다. 이를 이용하여 동적으로 생성된 Code 처리, 특정 코드의 발견, 실행중인 Process 분석 등을 할 수 있다. 주로 컴퓨터 구조 연구, 프로그램, 스레드 분 석에 이용되며, Taint Analysis 에 대한 개념, 각종 Tool 과 사용 방법, 간단한 예제, 최신 취약점 분석 등 을 통하여 DBI 를 알아보도록 한다. http://codeengn.com/conference/05

Introduction to IP telephony & VoIP

Kaushal Bhavsar

Yeastar MyPBX-Basic configuration

Hossein Yavari

The document provides instructions for basic configuration of a Yeastar MyPBX phone system. It includes the following steps: 1. Set up the network connections and configure the MyPBX's IP address, password, date and time. 2. Create extensions for the phones and trunks to handle incoming and outgoing calls. 3. Set inbound and outbound call routes to determine how calls are directed between the trunks and extensions based on numbers and schedules. 4. Configure other settings like voicemail, feature codes and security before backing up the configuration.

WordPress Security 101 - Meetup Nairobi March 2020

stk_jj

Getting Started with Twilio

Michael Kimsal

Edge Of The Web

Justin Mclean

VOIP services

Pankaj Saharan

This document provides an overview of VoIP services through a seminar presentation. It discusses how VoIP came about as an alternative to traditional circuit-switched telephony using the PSTN. VoIP allows carrying voice calls over an IP network by digitizing and packetizing voice streams using protocols like SIP and H.323. Some key benefits of VoIP include reduced costs, increased flexibility, and mobility. Popular VoIP service providers include Skype, while security poses ongoing challenges to VoIP adoption.

Pentesting VoIP

Vengatesh Nagarajan

This document discusses penetration testing of voice over IP (VoIP) systems. It begins with an overview of VoIP, describing how it allows phone calls over the internet and its common protocols like SIP and RTP. It then covers attacks like information gathering, eavesdropping on traffic, VLAN hopping, spoofing caller ID, and denial of service vulnerabilities. The document concludes with a checklist of penetration testing techniques for VoIP systems, such as VLAN hopping, extension enumeration, capturing SIP authentication, eavesdropping on calls, and callerID spoofing.

Fun with Linux Telephony

Donald Burr

This document provides an introduction to setting up voice over IP (VoIP) telephony with Linux. It begins with an overview of VoIP terminology. It then discusses the two main Linux VoIP software solutions, Asterisk and FreePBX, and recommends FreePBX. The document outlines the hardware needed, including softphones for computers and smartphones, as well as IP phones, analog telephone adapters, and telephony interface boards. It also discusses options when Ethernet is not available, such as Ethernet bridges, WiFi IP phones, and custom wireless solutions using existing cordless phones.

Avaya lync integration 6 16

Chris Stegh

Similar to Basic troubleshooting for Askozia IP PBX phone systems - webinar 2016, English (20)

Digital Signatures: how it's done in PDF

SIP trunking in Janus @ Kamailio World 2024

Green Code Lab Challenge 2015 Subject Details

Hacktrikz - Introduction to Information Security & Ethical Hacking

Defcon 21-ozavci-vo ip-wars-return-of-the-sip by pseudor00t

How to protect your business telephony from cyber attacks - webinar 2017, Eng...

authentication.ppt

Asterisk Complete Training

BlackHat Hacking - Hacking VoIP.

Sounds Like Botnet

[2011 CodeEngn Conference 05] Deok9 - DBI(Dynamic Binary Instrumentation)를 이용...

Introduction to IP telephony & VoIP

Yeastar MyPBX-Basic configuration

WordPress Security 101 - Meetup Nairobi March 2020

Getting Started with Twilio

Edge Of The Web

VOIP services

Pentesting VoIP

Fun with Linux Telephony

Avaya lync integration 6 16

More from Askozia

Askozia Telefonanlage: Fallstudie einer DECT-Installation

Askozia

Askozia y snom presentan su solución integrada

Askozia

En este webinar, introducimos snom y Askozia como solución VoIP conjunta. Snom es un fabricante de teléfonos IP y soluciones DECT con sede en Berlín, Alemania. Askozia es un fabricante y desarrollador de centralitas PBX IP e híbridas, que provee soluciones software y hardware. Mostraremos como, combinando estas dos soluciones, podemos conseguir un sistema telefónico comercial de altas prestaciones, eficiente y asequible.

IX Interconnection add-on for AskoziaPBX - webinar 2017, English

Askozia

IX Interconnection Add-on für AskoziaPBX - Webinar 2017, deutsch

Askozia

10 reasons for your costumers for choosing Askozia - webinar 2017, English

Askozia

10 Gründe für AskoziaPBX für Unternehmen - Webinar 2017, deutsch

Askozia

Wie Sie Ihr Unternehmen vor Cyber-Attacken schützen können - webinar 2017, de...

Askozia

VoIP bietet viele Neuerungen gegenüber ISDN und analog. Durch die enge Verzahnung mit der IT-Infrastruktur birgt VoIP aber auch Risiken die in traditionellen Telefonnetzen nicht existierten. Durch den Einsatz von Computernetzwerken als Basis für die IP-Telefonie kann bei unzureichender Prävention eine Gefährdung der gesamten IT- Infrastruktur, also auch der TK-Infrastruktur, die Folge sein. In diesem Artikel erklären wir, wie Sie Ihre IP-Telefonie absichern können.

Askozia VoIP Security white paper - 2017, English

Askozia

How to prepare a DECT installation - webinar 2016, English

Askozia

Was bei einer DECT-Installation zu beachten ist - Webinar 2016, deutsch

Askozia

Notrufnummern korrekt einrichten - Webinar 2016, deutsch

Askozia

Secure calling for IP telephony - webinar 2016, English

Askozia

How to switch from analog or ISDN to VoIP - webinar 2016, English

Askozia

Wie der Wechsel von ISDN auf VoIP gelingen kann - Webinar 2016, deutsch

Askozia

Anbindung externer IP-Telefone via VPN - Webinar 2016, deutsch

Askozia

Combining an External pfSense firewall with AskoziaPBX - webinar 2016, English

Askozia

VoIP offers many new features in comparison to ISDN and analog. However, as your IP phone system is now part of your IT infrastructure, VoIP is also affected by some risks that haven’t been existing for traditional analog and ISDN phone systems. If a network component is successfully attacked, the whole IT network infrastructure can be in danger. This now includes your IP telephony infrastructure. In this webinar recording, we explain why a firewall is a must-have, and how to connect a pfSense firewall with AskoziaPBX.

Anbindung einer externen pfSense Firewall - Webinar 2016, deutsch

Askozia

VoIP bietet viele Neuerungen gegenüber ISDN und analog. Durch die enge Verzahnung mit der IT-Infrastruktur birgt VoIP aber auch Risiken die in den traditionellen Telefonnetzwerken nicht existierten. Durch den Einsatz von Computernetzwerken als Basis für die IP-Telefonie kann bei unzureichender Prävention eine Gefährdung der gesamten IT- Infrastruktur, also auch der TK-Infrastruktur, die Folge sein. In dieser Webinaraufzeichnung wird erläutert warum eine Firewall dringend notwendig ist und, am Beispiel von pfSense, wie sie an AskoziaPBX angebunden werden kann.

Hürden bei einer Rufnummernportierung - Webinar 2016, deutsch

Askozia

Askozia 5 features: Stateboard and Client User Interface - webinar 2016, English

Askozia

In this webinar, we have a look at the Stateboard and Client User Interface Features introduced with Askozia 5 in early summer 2016. Whereas the Stateboard provides live statistics about the telephony situation, the Client User Interface allows the assign single users restricted access rights to the web interface of AskoziaPBX to customise settings such as language, voicemail and speed dials (BLF).

Grundlegende Fehleranalyse für Askozia IP-Telefonanlagen - Webinar 2016, deutsch

Askozia

More from Askozia (20)