I have several wireless routers and access points around my house but they're mainly used for cellphones. Everything else is wired. I have multiple audio receivers, TVs, Apple TVs, NMTs, PCs... you name it.
I had some semblance of a scheme whereby in each 2nd floor bedroom, there'd be a smart TV, Roku, Apple TV, AV receiver and PC (or PCs) and where ever they were placed - in a TV stand, rack mount rack, etc - those local devices were connected to a 5 or 8 port switch. That switch / those switches would be connected via a Cat5/6 cable to each other and one was dropped down through the wall to the living room where the FIOS router would be. It was similar in the living room and kitchen where several devices in close physical proximity would be connected to a switch and that switch cabled to the FIOS router. Every device in my house has a fixed IP and all are on the same subnet, etc etc etc
In my bedroom I had an ersatz server that would play HD video and music (mp3's, flac's, wav's) to just about anything you could view or listen on anywhere around the house. I have 3 Netgear NAS's which I could also stream music from in any file format anywhere.
I never had a hiccup from anything. I never had lagging in video, buffering in audio, nothing, ever, never: my Denon receivers would spit out any file format, I'd watch Blu-Ray rips on an NMT, etc. Never had any kind of issue. I mean, *really* never had an issue. E.G., I could use the 'Play To' feature in WMP from any PC in my house and play a wav to any of the 5 receivers.
I realized some time back that my server fans were loud and I'd hear that low-level white noise day in and day out so I came up with an idea: put that server, NAS's, Internet radio recorder in my cool, rarely used basement. My house is balloon construction so in a matter of hours, I had 25 cables dropped down there. Another upside was the cabling rat's nest by each rack would be way simplified.
All the switches were Cisco 2005's (6 of them?) and 3Com 3C1670800's (3). I'd bought 2 Tenda 24 port gigabit switches at a Black Friday special for $50+ each a couple years back that were still sealed so I mounted them to a wall in the basement where most all the cables came down. About 25' away, I sent up a plain Jane 15U rack and put the two PCs in them, then slapped together a little shelf for the 3 NAS boxes. I wired everything up and typical network functions seemed normal. Until...
I went to play a wav file and it stalled and hiccupped big time. I tried different files: no change. I could stream mp3s without a hitch, but flacs would buffer and wavs would just stop playing.
My first thought was the switches. I found out a long time ago that bargains are an excuse to eventually buy what you need, so I dropped $600 on a 48 port Netgear switch.
I'm going to answer my own question right now: cables. I bet I have a bum cable somewhere. I used mostly (90% or better) brand new cables and many of them were good quality shielded cat 5, way better than the Monoprice cables I used for short runs before (Yes, they are good cables).
I guess my confusion (other than the suggestion of a bad cable) was when I mounted the Netgear switch, I was convinced that would resolve it.