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In our first videocast episode, we identified what multipoint video conferencing is and how an MCU enables it either via hardware, hybrid or cloud solution.

But what does an MCU do exactly? Typically an MCU is tasked with a lot of different features and capabilities. An MCU usually takes all the audio and video streams from all the participants and sends them out to the rest of the group.

In its simplest form, an MCU will function as a “switch” where it detects who the active speaker is and only sends that particular attendee’s audio and video stream back out to the rest of the attendees. Today’s MCUs’ provide the functionality of a “mixer” – so that during the meeting an attendee can see all the rest of meeting attendees and not just the active speaker. To do so, the MCU will typically will have to transcode (encode/decode) which means it receives audio and video streams from the attendees (decodes), mixes them and resend (encodes). This is typically how MCUs function in a homogenous environment where endpoints more or less have the same capabilities when it comes to call signaling, and support of audio/video codecs. There are times an MCU will have to adapt as new capabilities are introduced in the endpoints, but for the most part the endpoints work in harmony with the MCU..

There are times an MCU will have to adapt to a few form factor capabilities and limitations, but for the most part the endpoints work in harmony with the MCU.

However, in a heterogeneous environment, today’s MCU needs to deliver a lot more, especially in order to deliver multipoint, multiplatform video conferencing. Over and above the typical media mixing functions, now the MCU has to be aware of different call signaling protocols and media formats supported by endpoints from different vendors. MCU must be equipped with endpoint intelligence to manage things like end-to-end encryption and video error resiliency.

Additionally, in a true multipoint environment, where users can be anywhere (inside or outside the enterprise walls), MCUs are now tasked to offer robust firewall/NAT traversal capabilities too. Content sharing/screen sharing is also becoming the norm and a must have for productive meetings, and the MCU has to be capable of delivering this functionality by working with different formats supported by multi-vendor endpoints.

The new MCU also has to take on security considerations and be able to adapt between intranets on the same network and those that fall outside of those networks. Content sharing is also becoming the norm and the MCU needs to be able to read between numerous formats.

How does the MCU perform in homogenous versus heterogeneous environments? You can check out the second episode of the on-demand videocast here to learn more.