CCTV cameras: single PSU or individual PSUs ?

[Curious.George]

Re: CCTV cameras: single PSU or individual PSUs ?

A POE switch inside a network is not a way into a network

Sure it is! Does your switch ensure that traffic originating/destined for that camera (PD) can't, instead, access other devices connected to other ports on the switch? I.e., can you unplug the switch end of the drop that services the camera (which is something an adversary could readily do) and plug in something ELSE to that port on the switch and ENSURE the switch won't let that "something else" access any other devices reachable from that switch?

How are you preventing this from happening, given that the camera is likely in a place where it can be accessed by adversaries (e.g., outside your home/business)?

Take an unused port on your router (or switch) and run it to a jack out by your front door and convince us that the other devices on your network (inside your home) are INACCESSIBLE to a casual user walking up with a laptop and connecting to that jack. I.e., you should be willing to put an unpatched MS OS on that internal network without fear that a passerby could hack it -- because the FABRIC would prevent such access.

Hint: I have two dozen (or more) external "drops" that you can walk up to day or night and attempt to do this. ALL of your traffic will be blocked from entering the switch. Additionally, traffic from the "legitimate" device expected to use each of those drops is constrained to only flow to its intended nodes -- so, even a misbehaving (i.e., HACKED) device can't talk to anything "unauthorized".

Extra credit: what happens if someone touches the business end of a Tesla coil to one of your "exposed" drops?

[shovenose]

Re: CCTV cameras: single PSU or individual PSUs ?

It's 2019, if you aren't using IP cams with PoE you're doing it wrong.

[diif]

Re: CCTV cameras: single PSU or individual PSUs ?

A POE switch inside a network is not a way into a network and whilst it might be a single point of failure it will be many times more reliable than a shitty Chinese 12v supply. I binned loads of supplies in 6 months and also the cameras and DVRs the shitty quality supplies had killed.

I've yet to see a decent picture from any analogue CCTV camera.

[Curious.George]

Re: CCTV cameras: single PSU or individual PSUs ?

A single power source is a single point of failure but using one means you can put the DVR and cameras on a UPS.
12v analogue systems are crap quality, POE IP cams are the way to go, they have a far better picture, only need one wire and can be put on a UPS even easier than 12v systems.

PoE switch is a single point of failure... It also gives an adversary a way into your network (not possible with analog cameras) -- even if only to subvert the hardware! (put 120V on camera feed and you'll just toast the video front-end but likely not propagate into the network to which the video interfaces)

OTOH, IP cameras have the added advantage of "having (flexible) smarts". While you can get analog cameras that will do motion detection, signal alarms, etc., you have to manually configure them AT the camera -- instead of "over the wire".

I have cameras and microphones integrated into my overhead loudspeakers (so I can communicate with anyone who is at/around the speaker).

[diif]

Re: CCTV cameras: single PSU or individual PSUs ?

A single power source is a single point of failure but using one means you can put the DVR and cameras on a UPS.
12v analogue systems are crap quality, POE IP cams are the way to go, they have a far better picture, only need one wire and can be put on a UPS even easier than 12v systems.

[Curious.George]

Re: CCTV cameras: single PSU or individual PSUs ?

I don't bother with that. I do IP cams with Poe and Cat6.

CAT6 is usually overkill for a camera.

[Curious.George]

Re: CCTV cameras: single PSU or individual PSUs ?

A single supply would be easier to swap out though, because you can just have a busbar where the cameras are connected and then connect that to the PSU.

That means you have to power each camera through a longer piece of cable as you now must "extend" the power connection to be of the same length as the "signal" cable. Individual power supplies (or, power supplied to "adjacent" cameras from a shared power supply) lets you (potentially) distribute power over a shorter run.

[CapLeaker]

Re: CCTV cameras: single PSU or individual PSUs ?

I don’t bother with that. I do IP cams with Poe and Cat6.

[Dannyx]

Good day folks. Having installed, or at least dealt with, a modest amount of cameras as part of my current job, I came across one aspect which seems to divide us in two schools of thought: those who suggest that a single PSU run ALL cameras and those who suggest that each camera have its individual power brick. For now, we went with the second option for all our installs, which is messier and takes longer to set up, but offers better redundancy, since if one brick were to fail, the rest would still remain up, whereas with a single supply....well, if it fails, ALL cameras go out. A single supply would be easier to swap out though, because you can just have a busbar where the cameras are connected and then connect that to the PSU.

Aside from that (and possible financial aspects), the main point was picture quality/distortion. One chap suggested having a single PSU run all cameras impacts quality and causes noise on the image, though I haven't tested or witnessed this myself to confirm. He invoked some sort of "impedance mismatch", to replicate his words exactly, but we haven't gone in depth here.
So, any thoughts on this ? Both from personal experience of CCTV guys out there and from an electrical perspective ? Cheers guys.