Frequently Asked Questions

What is Voice over IP? Many organisations today use data networks to connect multiple Local Area Networks (LANs). Most of those networks run TCP/IP, the communication language of the Internet. At the same time, these organisations also use another network, the public switched telephone network or a private wide area network, for all of their voice and fax calls. Voice over IP (VoIP) allows you to run one network and use it for voice and fax, as well as data. In practise, this often results in a significant reduction in voice network costs. What is this course about? This course provides you with a good conceptual understanding of the technologies that are used to implement VoIP. It covers in detail how the current generation VoIP equipment on the market works. It includes both the ITU-T and IETF standards. In particular, this course covers H.323, H.225, H.245, and H.248 from ITU-T and SIP, SDP and RTP from IETF. This course demonstrates a number of aspects of the technology, including a simulated international VoIP network with phones connected via routers, PCs, telephone exchanges, a VoIP PBX and Internet telephone calls. This course also provides direction for engineering a VoIP network as well as methods of measuring and correcting Quality of Service issues related to packet loss, delay and jitter. Various codecs are compared for sound quality and bandwidth usage. Who will benefit from this course? This course benefits anyone interested in using VoIP for cost savings or new applications, specifically telecom and datacomm professionals who are responsible for the development, planning, design, troubleshooting, management or administration of voice or data networks. We expect course participants to be fairly proficient with either telecom or datacomm technologies, but have a need to fill in the gaps before they can understand how to combine these two technologies. What background do I need for this course? Since VoIP integrates voice with data, participants should have some familiarity with either telephony or data networks. What is the level of technical detail in this course? This course provides enough detail for you to understand the important issues related to VoIP networking. This course is appropriate for both technical and non-technical participants. Many technical concepts are covered in detail. However, they are covered in a manner suitable for a wide range of attendees. The technical detail relating to SIP, H.323, RTP, and QoS will be useful to technicians and engineers in designing and troubleshooting VoIP networks. The concepts and strategies covered give planners and managers what they need to design and implement VoIP and multimedia networks. Will I learn whether or not my organisation is suited for VoIP? We show you how to evaluate this question in several ways. First, a model is provided that allows you to perform a cost analysis to determine if VoIP makes sense for your organisation from a financial point of view. Also, you learn to evaluate your current data networks to determine if they are suited to carry voice and data traffic in a combined network infrastructure. Important limitations and challenges when deploying VoIP are also covered. Does this course cover other voice-over-data technologies such as frame relay and ATM? Since IP is the most common protocol used for data networks, Voice over IP is the primary focus of the course. However, the course emphasises Voice over Packet Networks in general, and those interested in other voice-over-data technologies also benefit. You learn how to determine whether IP, frame relay or ATM is the optimum solution for your organisation. The course highlights the similarities and the differences so that you understand the advantages and disadvantages of the various possibilities. Does the course address Quality of Service? Quality of Service (QoS) is one of the most important topics in this course. You learn how voice quality is measured, which network characteristics affect Quality of Service and how to assess and control those parameters. You hear demonstrations of both low- and high-voice quality resulting from various network configurations, and learn how to determine if your network is suitable for VoIP. The course also includes details on how to size and design a network to deliver the required Quality of Service. What standards are covered in this course? The relevant standards for VoIP networking that are covered in this course include TCP/IP, SIP, H.323, ITU's G-series voice coders and Real Time Protocol (RTP). How much time is devoted to each topic? Content Hours VoIP fundamentals 3.5 Packet technology for carrying voice 2.0 Signaling for VoIP 4.0 Integrating voice and data 4.0 Quality of Service (QoS) for VoIP 4.0 Standards for VoIP 3.5 VoIP applications 3.0 Times, including the workshops, are estimates; exact times may vary according to the needs of each class. Does this course address multimedia or just voice? The primary focus of this class is on migrating legacy PBX voice traffic from a circuit-switched network infrastructure to a packet-switched infrastructure. This course does include demonstrations of the added features inherent in VoIP, such as video calls with chat, presence and whiteboard. What hands-on exercises are included in the course? The in-class hands-on exercises include: Setting up and confguring IP phones Making calls with H.323 and SIP protocols Measuring the effect of codecs on network bandwidth and consumption Calculating the degradation in voice quality due to packet loss, delay and jitter Engineering a network to carry VoIP using Erlang charts Configuring IP phones and gateways Configuring an IP PBX to add extensions and manage voice mail And much more! How does this course relate to other Learning Tree courses? 367, TCP/IP: A Comprehensive Hands-On Introduction provides a wider introduction to TCP/IP internetworking concepts 466, Cisco® Networking: A Comprehensive Hands-On Introduction is an excellent follow-on for anyone with existing Cisco router internetworks, who is looking to take advantage of Cisco VoIP capabilities 949, Telecommunications Fundamentals: Network Convergence has both a strategic and technical focus that helps you make sense of the complex options for applying modern technologies to converged networks