My memory is a bit hazy on this one - but I used to run the engineering team for... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

		arethuza on Feb 24, 2023 \| parent \| context \| favorite \| on: Reverse engineering a mysterious UDP stream in my ... My memory is a bit hazy on this one - but I used to run the engineering team for a company that did multicast based IPTV for hotels about ~2003 or so and I'm pretty sure the set top boxes used IGMP to control what video streams were sent to them - all devices on the fibre backbone got all the streams but each device in the rooms (connected by copper) could only handle a single stream. So multicast doesn't necessarily mean that every device gets every packet... I think. Also probably not worth using IGMP for audio.... :-)

bobdvb on Feb 24, 2023 [–]

It's often UDP/RTP delivery with SAP/SDP for announcement/discovery, then you use an IGMP join to attach to the stream.

The important thing about why you'd use IGMP Multicast instead of unicast is that you get a more assured latency which is important for audio sync.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact