Telos iPort Network Router User Manual


 
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Livewire-WAN Link
Livewire is a professional-grade IP Audio system, used over controlled local area networks. As a
modern replacement for older analog or TDM digital systems, it offers very low delay and high
audio fidelity. ere are a wide range of products made for broadcast studio facilities that take
advantage of Livewire: interface nodes for analog and AES3 audio, routers, mixing consoles,
dynamics processors, ISDN and POTS telephone interfaces, delay units, satellite encoders and
receivers, PC-based delivery systems, and – of course – codecs. Facilities span the gamut from a
single interface Node to multi-studio installations with dozens or even hundreds of connected
devices.
Because Livewire is uncompressed, it requires a lot of bandwidth: around 3Mbps for a stereo
channel. And because Livewire needs to be very low delay, it cannot tolerate a network with too
much latency or jitter. ese conditions are easily fulfilled with an inexpensive switched Ether-
net LAN. But these conditions don’t generally exist for wide area networks, which use telephone
lines and IP routers. e iPort bridges the two environments. It reduces the needed bandwidth
and accommodates the delay and jitter caused by WANs. Remember that 3Mbps rate? After
MPEG AAC compression, a typical rate would be 140kbps – over 20 times less. Most of the
reduction comes from the compression process, but some comes from using larger packets with
less header overhead.
If you already have a Livewire-based installation, the iPort is a simple and low-cost way to
extend it over a wide-area IP network. Connect the local network to one of the iPort’s jacks, the
WAN to the other, make some configuration choices, and you are ready to go. is application
nicely illustrates the advantages of IP Audio – were you to do the same thing with traditional
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