Issue link: https://www.e-digitaleditions.com/i/1255991
8 I ICT TODAY is the cost of the network; 1 GbE network switches are far more cost-friendly and offer a capital expense advantage for companies. There are many 1 GbE network switches available. They provide the buyer with a good selection and the ability to choose one that fits both the budget and network specification requirements. Another strong advantage of AVoIP network devices that run video traffic at 1 Gb/s over a 1 GbE network is the ability to run the signal over a longer distance. Data traffic that runs at a rate of 10 Gb/s over a 10 GbE network is more susceptible to electromagnetic interfer- ence (EMI) and radio frequency (RF) noise and runs at shorter distances. This can be a strong limiting factor when trying to run high-resolution video, such as ultra- high-definition (UHD) 4K/UHD at 60 frames-per-second. When copper cabling is used as the cabling infrastruc- ture, 1GbE network infrastructure devices benefit from the availability, cost effectiveness and maturity of Power over Ethernet (PoE) technology. Power over Ethernet can save costs and labor and expedite project completion. If PoE is not supported, every AVoIP device requires its own local power source that increases the complexity of the installation, thereby requiring specialized labor and potentially impacting installation times. To some degree, PoE can be used as a device management tool for AVoIP by enabling remote power cycles and power monitoring for edge devices. The main disadvantage of 1 GbE networks is that they are bit rate constrained. A 1 GbE network actually runs a net bit rate (removing IP headers and other layers of signaling and protocols, and using regular frames) of around 900 Mb/s. This represents the amount of bit rate available to work with versus the approximate 9000 Mb/s in 10 GbE networks. This is not always a limitation but is something to be aware of when weighing the pros and cons of one versus the other. 10 GbE – The Need for Speed High-resolution video consumes large amounts of data. For example, high-definition (HD) 1920 x 1080 resolution images running at 60 frames-per-second can consume up to 4.46 Gb/s while UHD video at 3840 x 2160 resolu- tion at 60 frames-per-second can consume up to 17.82 Gb/s. A 10 GbE network can pass HD video without video compression. Unlike 1 GbE-based AVoIP systems where video is always compressed in order to fit into the narrow bandwidth of 900 Mb/s, a 10 GbE AVoIP-based system often does not require compression in the case of HD video. When compression is required for UHD, the amount of compression required is very low, which is the most significant advantage of 10 GbE AVoIP systems; the amount of compression applied on video is minimal, if required at all. Simply put, when comparing the video quality of the streamed video with uncompressed video, it is bit- to-bit identical to the source. What the source produces is exactly what the display will show. Yes, some compres- sion is needed for UHD signals that can climb to 17.82 Gb/s, but the compression is very light versus compress- ing the same signal onto a 1 GbE network. This 10 GbE advantage may steer designers and installers away from 1 GbE networks. After all, who wants low video quality images running in meeting spaces or lecture/study halls? However, advances in compression algorithms and increases in computing power have resulted in impressive video quality to a degree of visu- ally lossless even when compressed to work in a 1 GbE pipeline. In other words, today's AVoIP encoders and decoders use advanced compression technology that makes it difficult to distinguish between the source and the compressed image when placing them side-by-side. For AV purposes, this means that a 1 GbE network can be sufficient. A 10 GbE AV network requires little to no compres- sion but uses the entire 10 Gb/s bandwidth provided by the network. The same 10 GbE network can accom- modate 1 GbE AVoIP alongside existing enterprise net- work traffic with ease, thereby eliminating the need for a dedicated 10 GbE AV network. NETWORK DESIGN Topologies A network topology defines how the various components of a network are arranged, including the various devices that the AVoIP system is connected to and how those devices are connected to each other. Although there are a variety of different network topologies, AVoIP encoder and decoder devices will nearly