This post is mainly focusing on NSX-T Multicast capability, so it’s important to understand Unicast. I’m not going to reinvent the wheel, a simple google search will give you enough information about Unicast. So I will keep it high-level here.
Unicast transmission
In unicast transmission, one sender is connected to one receiver. This is mandatory for conversational services but can be inefficient for other services since every client demands its own bandwidth.
For the case of a single transmitter unicasting a video at B bps to N receivers, the total bandwidth required is NB bps. The advantage of unicast transmission is that there is an intimate link between the sender and receiver, and hence a feedback channel can be established to signal errors and thus support retransmission and error control. Unicast streaming is used by operators such as YouTube and Skype.
reference: Link
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