Cabling Requirements And Emerging Technologies...

[Reefslayer]

Hello All,

I come from a networking SQL background. I understand networking but suffer significant gaps in my understanding of structured cabling and how technology requirements influence structured cabling solutions..
So here I am trying to brush up!!
What I'm looking for is just some general pointers in terms of the general office environment.

Looking forward to the possible implementation of voice over IP. What requirements does this place on the cabling employed? As higher bandwidth network solutions appear to be squeezing every ounce of performance from copper, is it conceivable that there simply wouldn't be any room for VOIP and say 10G over copper on the same cable?

Another element I need to consider is the possibility of power over ethernet. How does this impact the structured cabling in place. Would it require the installation of the latest cable? could it work in conjunction with VOIP and high bandwidth ethernet? Has anyone any experience with power over ethernet? I assume you may be able to power your IP phone along its net connection?

I know what I eventually want to do but I just don't know if I can do it!!

Any advice/ points of view gratefully appreciated.

Best Regards
Paul/Reefslayer.

 

[jimbopalmer]

POE uses all 4 pair of wire, so any structured wire or patch cables that JUST have 1, 2 , 3 & 6 won't carry the power, no trouble with the age of the wire, POE is not transmitting much signal.

VoIP itself is just IP in the wire, most of the challenges come in the switches and routers, keeping latencies low. Sadly you will discover all the low cost hub/switches under someone's desk as you deploy VoIP.

I tried to remain child-like, all I acheived was childish.

 

[DToolsDesigner]

IMHO if you really need 10 gig, fiber is the way to go. I have my doubts about ever being able to reliably and cost effectively do 10 gig over copper. Since it looks like cat 7 will be a screened and shielded 4 pair the cost of cable and termination I believe will make fiber the winner.
Sort of like the difference between trying to force a baseball through a garden hose (copper) or a 3" fire hose (fiber).
Certainly you could have a standard compliant wall plate configuration with a cat 5e or 6 for power and voice or a backup, and a fiber for data and/or VoIP.
Depending on the size of the installation and a few other factors, you can actually install fiber cheaper than copper.
Bottom line is, it is time to sharpen that pencil and really look at total cost of ownership before deciding which way to go.
My final point would be to really examine your bandwidth needs, is 10 gig a necessity or just a nice to have technology? After all, right now the fastest throughput you can get from a hard drive is less than 300 Mb/s, far below 1 gig.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[Reefslayer]

Many thanks for the contributions guys. All appreciated.

 

[jimbopalmer]

Some bandwidth comments: you can get 24 analog voice channels in a T1 (1.5 meg) the VoIP is not much different requirement for bandwidth so 10 gig is 150,000 symultanious calls, an unlikely amount in most organizations, even if you plan on mixing 90% Data 10% voice, 15,000 calls at once is a large organization.

You might want to look into how much voice bandwidth you use now.

I tried to remain child-like, all I acheived was childish.

 

[rsmadhava]

I understand that some cisco products supply power on same wires which carry Ethernet i.e, pair 1,2,3,6

There are also products which supply power through unused pairs like 4,5, 7 and 8. It is impornat to know more details of the product used to power up IP Phones.

 

[franklin97355]

Cisco has power over ethernet but the power is on pins 4 and 5 I believe.

 

[fonedude]

3 Com presently provides an add on box which provides power over ethernet. It will be integrated into the next version of the NBX. It is also autosensing, only turning on on ports where needed.

 

[jpm121]

There are also mid-stream patch panels that will take an incoming RJ-45, add on power, and then patch to another RJ-45 for the rest of the run.

Part of the 802.3af standard is that it has to be auto-sensing so it doesn't fry non PoE parts that get plugged in.

 

[PhoneGuy2000]

Your VOIP solution will run on your standard network cabling. Most jack manufacturers state that they are VOIP compatible, and 1 (Hubbell) actually guarranties VOIP using their product with any of the mainstream cable manufacturers. Also, at the Nashville BICSI show, we got a presentation about 10 Gig over copper. The industry is waiting for the IEEE to approve something like 649 MHZ as a frequency. They feel they will be able to push 10 Gig over Cat5E (not to be confused with Cat5e) and Cat6. Still, Richard is right. Fiber will transmit it more reliably and it won't be marginal. Consider installing a Cat5E and a 2 strand fiber Cable (not a zip cord) to each station. That would be standards compliant and you can use either cable for high speed data.