1

Since I have been doing a lot of IP camera jobs lately, it was only a matter of time that something really long-distance, more than can be covered with cat5e/cat6 cable, would come up. My current client needs to have a number of IP cameras installed at the perimeter of his estate, and also to link the main house with two auxiliary buildings, a guesthouse right next to the main one, and a personnel bunk about 400 meters away.

It needs to be said now that my client has explicitly (and repeatedly) stated that no wireless solution is to be considered.

My plan of action is to use multimode fiber optic cables for the cameras, along with ethernet-to-fiber media converters. I would avoid this, but distances from the house to the perimeter of the estate vary from 100 meters, to nearly a kilometer. I am hardly a fiber expert but I have good experience in this simple kind of installation from my previous job.

To the actual question:

Since I will anyways be using fiber for the personnel bunk, is there any advantage to using PPP instead of Ethernet for the link?

I have done a little research, and know, more or less, what PPP offers. BUT, I do not need in any case any of the more advanced features of the protocol like multi-link, authentication, compression and the like. Security is pretty much covered, since the fiber will be buried. All the links are point-to-point and there is no need for compression.

Still, is there any reason to choose PPP instead of Ethernet? I do not object to a little (or even some more) studying, since I have a wide timeframe for this. I need to do a really good job, and a "clean" one here, so I need the best option.

If you can point me to more reading, or some suggestions to help me choose I will be grateful.

Mark Henderson
  • 68,823
  • 31
  • 180
  • 259
dlyk1988
  • 1,674
  • 4
  • 24
  • 36
  • 3
    It sounds like you've answered your own question: `I do not need in any case any of the more advanced features of the protocol like multi-link, authentication, compression and the like` - why make things more complicated than you need to, making it harder to support? This is not an official answer though because it's not a technical one. – Mark Henderson Sep 08 '13 at 23:38
  • 2
    Few other things to think about: With fibre, how are you going to power the remote cameras and media converters? If you have to get power from elsewhere, I'd suggest running CAT5 from wherever the power source is instead and doing PoE. Then you can do fibre backhaul from there if need be, as you will probably be able to get a few cameras terminating at the same location to make backhaul easier, and then you don't need bulky hardware mounted ontop of a fence or a pole or whatever – Mark Henderson Sep 08 '13 at 23:41
  • @MarkHenderson Very good observation. That is what I initially thought, but... There are TWO mains lines running along the perimeter for lighting and alarm sensors, although neither got installed in the end. Also, it does indeed sound like I already have the answer. The thing is that because of my inexperience I might be missing something? Perhaps something fiber-related that makes PPP vastly superior to Ethernet for this scenario. – dlyk1988 Sep 08 '13 at 23:46
  • Nah, I think PPP is just going to make things worse. **IF** your cameras have PPP support built into them, *and* you have pre-existing PPP hardware at the other end, maybe it's worth doing as an exercise It can make some things simpler, as there's no default gateways per-se to worry about (everything goes over the PPP link, no matter what) and it can prevent new devices being connected, but there are other ways of doing this stuff anyway. – Mark Henderson Sep 08 '13 at 23:51

1 Answers1

7

Personally I wouldn't bother. You would need:

  1. Cameras that support PPP
  2. Hardware at the other end that supports PPP
  3. To power media converters and the cameras

This is just making something that's already reasonably simple into something that's more complicated when it doesn't need to be.

You've stated that there is already power running around the perimeter of the campus, but to make things simpler, you probably want to remove as many things as possible from the actual camera installation.

Personally, I would be running fibre to a central location, and then using PoE to distribute power and data to each camera from there. Media converters are not small, and need power, in addition to the camera needing power and data. So to contain all of that in the one space you need:

  1. Camera
  2. Media converter
  3. Power for media converter
  4. Power for camera
  5. CAT5/6 from convert to camera
  6. Fibre to the media converter

But if you ran fibre to a central location, and then ran just ethernet with PoE you have:

  1. Camera
  2. Cat 5/6

And that's it. Obviously I don't know specifics about this campus so I don't know if there is space on the inside of the fence that you can bury this stuff and still get access to it, or if you'd need to run the whole thing from a few different nodes.

Depending on the cameras you choose, they may need more power than PoE can provide (e.g. a heavy camera housing with PTZ), in which case you may need to throw in an additional power lead for that. (fwiw, most security cameras I've seen lately really suck. They are either nice units but rubbish resolution, or high resolution but have IR filters so they're no good for night vision, or cost $1,000/each. Good luck with your research. And if you do get a high res camera capable of 20+fps, storing that amount of data becomes a whole different nightmare).

But either way I don't think that PPP is the way to go.

Mark Henderson
  • 68,823
  • 31
  • 180
  • 259