Gigabit vs 100Mbps POE+ Switches for cameras

[Tuckerdude]

Hey folks, just a general question on Ethernet switches.

I've run a total of 32 cameras both internally and externally at my house. Up to now, I've made sure that when I extend my network runs (particularly outdoors), that I use Gigabit POE+ switches. I will typically install them mounted inside waterproof enclosures and have had years of trouble-free service.

The only issue is the size of these things. Believe me when I say that I've shopped around, and purchased quite a number of these so it's not without looking. However, if you drop down to 100Mbps, there are numerous and quite small (we are talking 3x4 inches in some cases) switches to be had! Of course, the power brick that goes along with them can be big, but that's a separate issue.

So the real question is....would I be better off sticking to the gigabit switches, or is it overkill if all I am doing is connected cameras to them? Again, these switches are dedicated solely to providing power and Ethernet connectivity.

Any thoughts or insights would be greatly appreciated!

 

[mat200]

Hi Tuckerdude,

In general you do not need Gbit switches for these cameras.

You can check the specs on the switch and the cameras and confirm the details.

 

[fenderman]

if you are running 32 cameras to a single switch or cascading them you need gigabit..or at least a gigabit uplink

 

[mat200]

Hi Tuckerdude,

I like to have all my camera directly connected to a switch, this increases reliability.

Clearly you've got a number of downstream switches, which works for you.

So here's an example to determine what you need and to get an idea.. this isn't perfect but will give you an idea:

Look at your camera model and lookup the Bit Rate, for example
IPC-HFW4830E-S
8MP IR Mini Bullet Network Camera
Bit Rate
H.264: 24K ~ 10240Kbps
H.265: 14K ~ 9984Kbps
IPC-HFW4830E-S - Dahua Technology

Let's say you have 7 of those on one PoE switch - and one port for the uplink

7x10.24Mbps =< 72Mbps

Also remember there will be an overhead for the TCP packets typically < 10% so we'll use 10%
72+ 7.2 = 80Mbps

So that segment can do ok with 10/100 switch

Naturally the upstream switch as fenderman points out will need to be Gigabit, or if you have more bandwidth consumed by the cameras you will need a 1Gb uplink.

Of course it maybe easier just to get 1Gbit switches and not calculate the details and have lots of available bandwidth.

When looking at switches do pay attention to what the backplane of the switch can handle.

Personally I would rather buy one nice switch than have a lot of little switches to keep an eye on.

 

[NoloC]

Hi Tuckerdude,

I like to have all my camera directly connected to a switch, this increases reliability.

Clearly you've got a number of downstream switches, which works for you.

So here's an example to determine what you need and to get an idea.. this isn't perfect but will give you an idea:

Look at your camera model and lookup the Bit Rate, for example
IPC-HFW4830E-S
8MP IR Mini Bullet Network Camera
Bit Rate
H.264: 24K ~ 10240Kbps
H.265: 14K ~ 9984Kbps
IPC-HFW4830E-S - Dahua Technology

Let's say you have 7 of those on one PoE switch - and one port for the uplink

7x10.24Mbps =< 72Mbps

Also remember there will be an overhead for the TCP packets typically < 10% so we'll use 10%
72+ 7.2 = 80Mbps

So that segment can do ok with 10/100 switch

Naturally the upstream switch as fenderman points out will need to be Gigabit, or if you have more bandwidth consumed by the cameras you will need a 1Gb uplink.

Of course it maybe easier just to get 1Gbit switches and not calculate the details and have lots of available bandwidth.

When looking at switches do pay attention to what the backplane of the switch can handle.

Personally I would rather buy one nice switch than have a lot of little switches to keep an eye on.

Or anotherwords WHAT @fenderman SAID.

 

[mat200]

Or anotherwords WHAT @fenderman SAID.

Hi NoloC,

Do note that sometimes going through the math is educational and helps us with a better understanding of what we're looking at.

Also note: the answer is a bit more nuanced, the calculations are conservative - using the max bit rate and a good % for the TCP overhead.

Example - I can have about 10x 10/100 switches with 7 cameras each feeding into one 10/100 switch which has a 1Gb backplance and 1Gb uplink. Thus not all switches would need an 1Gb uplink in this case, only the "mother" switch which would in turn feed the streams to a BI PC or NVR. With h.264/h.265 we're seeing quite an improvement with bandwidth utilization.

 

[Tuckerdude]

Hey folks...many thanks for the replies!

mat200, totally appreciate you taking the time to explain your answer. It WAS educational, and helps in my overall understanding of my network topology. For clarity, I will say that up to now, I've used Gigabit switches in every case except for when I wanted to hang two cameras off a single ethernet cable using a splitter. As "dicey" as that sounds, these little splitters work extremely well and don't require a power source of their own to function. They simply take a single POE line and split it into two so you can get two (bullet cams, not PTZ) onto one. But the rest are GB switches. I think I will experiment with one of these super-small 100MB switches and see if I notice anything. I just received this one from Amcrest:

https://www.amazon.com/gp/product/B074ZTNHNW/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

It's TINY and provides 4 ports of POE+ connectivity. The dimensions on the switch are 2 3/4" x 3 3/4". And even though the power brick is bigger than the switch itself, it does afford me the chance to downsize the waterproof enclosure I would need to house it. I'm all about trying to make my installs disappear into the background as much a possible. Sometimes it's not possible, but in some cases I've been able to be quite "Stealthy". Here is a picture of the little switch for size comparison:



Anyway, I wanted to say thanks again for the responses, super helpful! Have a good weekend guys!