[SOLVED] poe switch

[velocci]

Hi all, I have a 16 port non-poe switch. I've outgrown that switch and now i'm also getting security cameras that are powered using poe. If i just buy a small 8 port poe switch and plug that into my current switch or plug it into the main router, will that slow down my network speed as opposed to buying a new 24 port poe switch and plugging all my devices and cameras into that?

 

[Math Geek]

that depends on speed need. by plugging a second switch into the first one, you limit total bandwidth from the cameras to that single port speed.

it may be good enough, it may not. you'll have to look at the cameras and see what their needs are. if it's good enough, then go for it. otherwise you'll want a new switch where each device can gets its own port. if the cameras do not use the internet but only local network, then it won't slow internet access any but your total network bandwidth will of course take the hit. againyou'll have to do some looking and see if the cameras need a lot of speed or not.

 

[DeauteratedDog]

that depends on speed need. by plugging a second switch into the first one, you limit total bandwidth from the cameras to that single port speed.

it may be good enough, it may not. you'll have to look at the cameras and see what their needs are. if it's good enough, then go for it. otherwise you'll want a new switch where each device can gets its own port. if the cameras do not use the internet but only local network, then it won't slow internet access any but your total network bandwidth will of course take the hit. againyou'll have to do some looking and see if the cameras need a lot of speed or not.

I don't think this logic applies in this situation.

Assuming either local storage on a single NVR or cloud storage, the cameras are going to be sharing a single port going into the NVR (or cloud) anyway, so sharing a port on the camera side shouldn't matter.

Also, 1 Gbps / 7 cameras = 140 Mbps per camera. Not a problem for any consumer or almost any pro camera.

 

[velocci]

i get the problem with plugging the smaller poe switch into the 16 port switch sharing the 1Gbps bandwidth, but what if I plug the 8 port poe switch into the main router? the router has 4 ports. each switch gets its own port on the router. wouldn't that be like having a single 24 port switch?

 

[bill001g]

All depends on the traffic path Say you hook switch 1 to port 1 and switch 2 to port 2 of the router.

The total bandwidth between the 2 switches is 1gbit. If you cameras and the dvr are all on a single switch all the traffic will just go between those devices. There is still a full 1gbit going to the router and the other switches.

The problem would come if you put the dvr on 1 switch and all the cameras on the second. All this traffic would have to pass the router. It would only affect those 2 ports in the router things connected to the other 2 would not be affected.

The lan ports on a router are in effect a 5 port switch. 4 ports you can see and a 5th port going to the router chip.

Pretty much all port on any modern switch can run 1gbit up and 1gbit down all at the same time. The limitation is more if you attempt to pass more than 1gbit over any 1 port.

 

[velocci]

I may use the QNAP NAS TS-653D as my NVR. I can plug the NAS and the cameras in the same switch so that would help, or all my most important devices on one switch, that would help right? but in general, without considering what devices I have, two switches plugged into the main router using their own port is generally the same as having the one big switch right?

 

[USAFRet]

I may use the QNAP NAS TS-653D as my NVR. I can plug the NAS and the cameras in the same switch so that would help, or all my most important devices on one switch, that would help right? but in general, without considering what devices I have, two switches plugged into the main router using their own port is generally the same as having the one big switch right?

With the NAS and cameras on the same switch...data flows from the camera, to the switch, and then down to the NAS.
It travels no further up the chain.

All data from that switch flows upstream to its parent router or switch, through on gigabit connection and port.

 

[velocci]

ok I'm not sure what you're trying to say there, due to the fact I'm not an expert at networking. are you saying that 1) if the devices are on the same switch, then the speed between the devices is not affect and 2) if the devices are on two different switches, the speed between the two devices will get reduced?

 

[USAFRet]

ok I'm not sure what you're trying to say there, due to the fact I'm not an expert at networking. are you saying that 1) if the devices are on the same switch, then the speed between the devices is not affect and 2) if the devices are on two different switches, the speed between the two devices will get reduced?

Yes.

Each port is gigabit capable., up and down.
All devices on ONE switch, each get that gigabit transfer speed when transferring between them.

4 cameras and the NAS on one switch, they all talk to the NAS at gigabit speed.

Now...if the 4 cameras are on one switch, and that switch is connected to another switch via one port and cable, and the NAS is on the second switch...all 4 cameras are sharing that gigabit upstream port.


But in the context of your cameras...all 4 at the same time won't saturate a single gigabit port transfer speed. So no worries either way.

 

[velocci]

no, I would put both switches to the router and I would put the cameras, nas and the computers that i use to transfer files to and from on that same switch. everything else will go on the other switch.

is there a poe switch with 24 ports that's under $200 Can? I'm having a problem finding one. not all ports need to be poe. I would only need 4, but ideally would like to have more for possible future need.

 

[USAFRet]

I'm not seeing a 24 port for that.
16 (8+8PoE) for $170
https://www.amazon.ca/TL-SG1016PE-TP-Link-Rackmount-Web-Managed-802-11at/dp/B0721V1TGV

 

[velocci]

ok thanks. I'll keep looking.

 

[SamirD]

You need to think of the switches as plumbing pipes.

So if you have a tank of water with 4 ports, each port can get the same speed for water flow.

But as the water from a single port flows down to another tank with 16 ports, while individually each of these 16 ports can flow as much as the previous 4 ports, the maximum flow of water from the top tank will be limited to the flow of a single port. But this only applies when water is flowing from the top tank down to the next one.

The same applies the other way around where the 16 port tank is on top and the 4 port is on the bottom. The maximum flow from the 16 port to the 4 port will be limited to a single port since that's how they're connected.

Now, as everyone has mentioned, it shouldn't matter at all as all the cameras combined don't have enough water to even fill a single port. So tank to tank limitations won't apply.

 

[velocci]

so lets say I have 4 computers. computer 1 is transferring files to computer 2 and computer 3 is transferring files to computer 4, all at the same time. Lets say I just have one switch. so i would still get 1gbps transfer rates (theoretically) on each of the 2 transfers?

 

[USAFRet]

so lets say I have 4 computers. computer 1 is transferring files to computer 2 and computer 3 is transferring files to computer 4, all at the same time. Lets say I just have one switch. so i would still get 1gbps transfer rates (theoretically) on each of the 2 transfers?

Yes.

 

[SamirD]

so lets say I have 4 computers. computer 1 is transferring files to computer 2 and computer 3 is transferring files to computer 4, all at the same time. Lets say I just have one switch. so i would still get 1gbps transfer rates (theoretically) on each of the 2 transfers?

Yep! Most switches today have more than enough bandiwidth for full duplex transfers on all ports. So the 4 port switch in your example will have an '8Gbps switch backplane'.

The only time you really have any bottlenecks are between switches since you have to use a single port limited to 1Gbps full duplex or 2Gbps. (Now, there are what are known as 'stackable' switches that use special cables to connect the switch backplanes together, but that's enterprise level equipment.)

And generally these bottlenecks aren't even important as there isn't much out there that fully utilizes gigabit bandwidth. But nas units can depending on their capabilities so if your example, computer 1, 2, 3, 4 were transferring from the nas and the nas was capable of transferring fast enough to saturate 1Gbps x4 computers, it would actually be limited by its single gigabit connection to the switch. This is why a lot of higher performance nas units have 2x ethernet ports or 10Gbps capability.

 

[velocci]

wow, you guys just blew my mind. I always thought the most I can have throughout my home is 1Gbps in total. That's what I thought 1Gbps on a router or switch meant. I didn't know it meant on each port. wow! i'm glad I asked.

 

[SamirD]

wow, you guys just blew my mind. I always thought the most I can have throughout my home is 1Gbps in total. That's what I thought 1Gbps on a router or switch meant. I didn't know it meant on each port. wow! i'm glad I asked.

Glad you learned something new! Back in the day, it was a 'shared bandwidth' in something called a hub which worked exactly like a switch except that all the ports shared the bandwidth. So a 5 port 100Mbps hub would share all the bandwidth between 5 ports versus a 5-port switch which would give each port a full dedicated 100Mbps--a 5x jump in performance.

Can you imagine how big of a leap a shared 10Mbps network made when it went to a switched 10Mbps network? And then 100Mbps? And then 1Gbps? I've seen the jumps and it's remarkable. 10Mbps used to be as fast as a network could go and now it's considered 'slow' Internet access. :O