AVIXA CTS Study Group

AVIXA CTS Study Group

A space for those seeking a CTS, CTS-I and/or CTS-D Certification.

What's the difference between Upstream and Downstream Devices?

Started 29 days ago

Hello Everyone. I was recently watching some training videos from Extron and Q-Sys saw them mentioning upstream and downstream devices. But these were never defined in these courses neither I could find anything regarding Upstream and Downstream in CTS Exam guide. Not much info is available on internet either regarding AV upstream and Downstreams

I would really appreciate if someone could explain what are upstream and downstream devices/signals.

As I understand it, upstream is the information or data that you upload from a node to a server (it could be the cloud) and downstream is in the other direction from the server to a node, but I share this link from IBM that can help you.



Interesting question.

Upstream and downstream devices come in consideration when you design a system and how efficient equipment should operate in general. 

Upstream devices can be any device or platform that accept traffic from reporting devices.  

Downstream devices can be any equipment that take its intended operation application/firmware from a central repository location. 

While AV and network devices becoming more popular and simple to use, it is always beneficial to involve Network/IT Teams at the beginning rather the last minute delivering the projects to the clients.


If it helps, think of your IT network (and OT, if you distinguish between them) as a mountain with a stream of water flowing (gravity means it flows down the mountain). Just like your IT schematic, the mountain is smaller at the top. Downstream is going from narrow to wide, upstream is going from wide to narrow (typically up towards a server, whether it be on-prem or in the cloud). The same logic applies to the words 'uplink' and 'downlink'. And if your IT is wireless, remember that base-stations are often found at the top of a hill.