[mythtv-users] Ceton Based Recordings Failing

[Stephen Worthington]

On Sun, 15 Jul 2018 09:54:29 -0700, you wrote:

>I was having trouble at work getting enough bandwidth for GigE (gigabit ethernet) cameras and found that, depending on the switch, other devices plugged into the switch can cause all ports to be limited to the device's max speed (like 100 Mb, or even 10 Mb).  Might try verifying your speed, especially if you've plugged in a new device, lately. 
>
>
>Dave D.

That is a very strange switch then.  The way Ethernet switches work
means that each port is independent, and has independent buffers for
all its traffic.  When a 100 Mbit/s device is plugged into one port
and its traffic is going to a 1000 Mbit/s device on another port, the
switch buffers the incoming 100 Mb/s packets and sends them out at
1000 Mbit/s, and vice versus.  Only the traffic on the 100 Mbit/s
device is limited to 100 Mbit/s.  If the speed on any other port is
affected, then by definition, the "switch" is not a switch, but
instead it must be a hub.  But I do not know of any 1000 Mbit/s
Ethernet hubs - hubs were only made up until the speed increased above
100 Mbit/s.

What can happen occasionally, is that a 1000 Mbit/s device is plugged
into a 1000 Mbit/s port on a switch, but the speed negotiation fails
for some reason, and it only connects at 100 Mbit/s.  The usual cause
of this is a bad cable or bad socket.