James, a big part is product availability. Most manufacturers who offer NVRs do not offer NVRs with PoE switches built in, so that is a limitation.
That said, I will presume you are already looking at a manufacturer that offers both.
There's clearly benefits: simpler setup, one less device to buy and maintain, less space, etc.
The main downsides are: fears about reliability (what if a port or the whole embedded switch fails), and limited scalability (boxes are often limited to 8 ports even if they support 16 channels or more).
We prefer a separate managed switch so we can have more versatility. We commonly are also installing wireless APs (UBNT) which need 24V PoE. We also like the ability to power cycle ports individually via the switch GUI instead of running onsite to do it manually, or reboot the whole switch, which brings all ports down.
If you have a very small install and the budget won't allow a $200 switch, I guess a built in PoE switch may be your only choice, but thankfully we haven't had that issue yet.
There are practical reasons for both. First, if you don't know the difference between a managed and unmanaged switch, IMO, then it really doesn't matter, does it? Second it can be a way to get around "company standards" where the end users mandate a Cisco Switch for data that will cost as much for additional ports as the entire CCTV install. I know of a site that has to install a 24 Port Cisco Layer 3 for any expansion if the switch is full. Third, you don't have to worry about the cameras being issued new IP addresses by the customers DHCP server if you didn't set them as static in the device / switch. Lastly it then becomes a "piece of hardware" and just a component of the CCTV system with no direct interaction on the customer network and less security exposure with external cameras. All of that said, someone strong in IT would have an easy time configuring a managed switch and would gain value from it, especially if using a server based VMS. At least, that's been my experience.
We do it with Dahua and for up to 8 cameras it is fine - we have a few sites. I think now they have a 16 channel NVR with 16 PoE ports but I am really wondering if the power supply is really good enough to power 16 cameras - even some of the good 16/24 port PoE swithces have power limitations. Nevertheless we will try testing the 16PoE NVR also because as mentioned above there are reasons:
2) Space - you do not always have a rack, residential install, e.t.c
3) Less "Complexity"
4) PoE switches are loud
5) Very small resi project where there is no need for a PoE and price and noice are factors
P.S. I am not in favor of PoE NVRs but then again - even though I had reservations at the beginning - I am surely not against them also.
Jon, Good points, all are valid. I would argue that I would love to sell Lamborghinis and if you ask them they are the only way to go. However I know a few Toyota and Ford dealers that reside in mansions selling something lesser in stature. Every market has a variety of end user requirements and people to fill them. Should I feel bad if I sell and maintain Ford's?
On larger commercial jobs, I wouldn't even consider it.
But on a 4 cam basic domestic job? Every day of the week.
IPVMU Certified | 02/20/15 02:56am
We have used some Avigilon appliances, they have a built in manged switch. So far they have been great for smaller installations.... NVRs with integrated switches have a small footprint which is nice especially if space in a rack is limited or if being installed into a small room...