[LAD] AoIP question

I have been doing some reading on audio over IP (or networking of any kind) and one of the things that comes up from time to time is collisions. Anything I read about ethernet talks about collisions and how to deal with them. When I was thinking of a point to point layer two setup, my first thought was there should be no collisions. Having read all the AES67 and other layer 3 protocols there does not seem to be mention of collisions really. My thought is that on a modern wired network there should be no collisions at all. The closest thing would be a delay at a switch while it transmitted another packet that in a hub would have been a collision. So my thought is that AoIP at low latencies depends on a local net with no collision possible. Am I making sense? or am I missing something? The various documents do talk about three kinds of switches, home, enterprise and AVB. It is quite clear what makes an AVB switch, but what does an "enterprise" switch have over any other switch aside from speed? I am sure I am being small minded in my thoughts here. For example, I am expecting very little non-audio bandwidth and I am guessing that the average home switch does not prioritize any style of packet over another. I guess I am asking what parts of a switcher are important for audio? I am guessing that HW encription (offloading the SSL from the server to the switch) is not something that helps audio. Even with proprietary protocols, it would not make sense to use encription. There seems to be a real plug and play emphasis where the audio enabled LAN is firewalled from the rest of the world. The streams are multicast so any box that recognizes the packets can use those channels and offer it's own audio channels. Any box can send control messages to reroute audio... there must be some kind of authentication for that.... (light bulb) this is why AES67 does not include controls and perhaps discovery either. I can just see someone walking into a concert with a notepad and deciding they want their own mix... I am guessing the promoter would not want people walking away with their own "direct from the mixer" audio track of the event either. Not quite plug and play then. The wireless router wants to limit what traffic it deals with. So AES67 allows the control to be offloaded to a web interface with access control (switch SSL offloading would not help here anyway). Discovery ends up being manual at first glance. I am thinking it will not be long before the control and setup will automate loging into the web IF and setting things up. A system wide user/password and an interface that defaults to streaming it's own inputs as multicast is already discoverable. -- Len Ovens www.ovenwerks.net