Is there any way how to extend LifeSize Phone cable e.g. 30m?
yes you can use a Lifelink Adapter to Ethernet, up to 60m / 200 feet
Not trying to nit pick but this answer is misleading.There is no such thing as a LifeLink to Ethernet Adapter. It's a twisted pair (CAT5) balun. You should never plug this into an Ethernet port.
Attaching the LifeLink adapter document.
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