Media Encapsulation

Encapsulation is the process of taking a data stream, formatting it into packets, and adding the headers and other data required to comply with a specific protocol.

The process of encapsulation is tuned to meet the performance requirements of different applications and networks.

Any data that is transported over an IP network needs to be encapsulated into IP packets. Also, a variety of data needs to be inserted into each packet header, including both the source and destination IP addresses, the Time-to-Live of the packet, the packet's priority indication, and the protocol that was used to format the data contained in the packet (e.g. UDP, TCP).

Packet encapsulation is done in real time, just before the packets are sent out over the network because much of the data going into the packet headers change for each user.

Media Encapsulation process in SMPTE ST 2022-6

Making Packets

IP packets are constructed in a layered fashion. At each layer devices are operating only with the information contained within the associated header. An Ethernet switch only cares about the layer 2 headers and everything else is just payload. layer 3 sees the header and doesn't care about the lower-level transport. The application doesn't care about headers at all, they just deliver their data to the network and expect to get the data back at the other end (Church and Pizzi, 2010).






References
Church, S. and Pizzi, S. (2010). Audio over IP. Burlington, MA: Focal Press.