I can’t be sure exactly why you’re being told you need multicast, but keep in mind that if you are recording every camera - since it’s not a Meraki MV solution - there will be a video stream from every camera to the recorder (DVR). With 176 cameras that may be a fair amount of traffic, even before you account for operators viewing the streams.
@demazter we have ~1000 cameras running over a mixture of Meraki and Cisco infrastructure with most being remotely live viewed over a multi-link Meraki SD-WAN. However we are using MileStone XProtect, but the concept should be similar.
What type of cameras are they, IP or analogue?
What quality settings do you have and how much bandwidth does each stream use?
Does playback work okay?
What are the traffic levels on the recording servers and encoders?
Is anything else in that VLAN? - we keep IP camera to recorder and encoder to recorder in one dedicated VLAN at each site.