Ric_ Posted October 11, 2007 Posted October 11, 2007 For those without the cash for PoE take a look at http://www.automatedhome.co.uk/New-Products/Neat-Power-over-Ethernet-Injector-Cables.html Seems pretty obvious really.
FN-GM Posted October 11, 2007 Posted October 11, 2007 Could be useful for certain things, did you find it hard to understand her accent
Joedetic Posted October 11, 2007 Posted October 11, 2007 PoE is great. We have two Cisco PoE switches in the cisco lab at uni for IP Telephony. You can remotely reboot devices too just by running the shutdown and no shutdown commands, which is great if you've got 8 phones on a test rig and really cba to go round pulling the cables or remembering the button sequence to reboot. The only problems with it are that when it comes to gigabit, obviously you cant use it because of gigabit using all of the cables in your cat5e / cat6. So, as i was thinking to myself today, PoE could be one of the major affecting factors in the development of the next standard copper network media. For example, they'll need an extra pair for the power. Then on top of that there is the question of future proofing and not just enabling the present. (If you get what i mean). How many more pairs do they put in for future developments or will they try and get gigabit down 3 pairs leaving one for the PoE? Or will they move away from the PoE idea for faster speeds and leave it for 100mbps only or maybe just forget PoE and copper totally?? These sort of things fascinate me (obviously or i wouldnt be studying network engineering!)
srochford Posted October 11, 2007 Posted October 11, 2007 The only problems with it are that when it comes to gigabit, obviously you cant use it because of gigabit using all of the cables in your cat5e / cat6. You may need to explain that to the switch manufacturers :-) eg Netgear have 24 and 48 port gigabit switches with PoE on all ports: http://www.netgear.co.uk/smartmanagedswitch_gigabit_ethernet.php
Joedetic Posted October 11, 2007 Posted October 11, 2007 Oh I don't bloody know what's going on there lol. That's what we were taught on CCNA1 and 2 and are being taught on the IPT course so...meh. Dunno wtf that's all about. Is it PoE on the links that are negotiated to be gigabit? or is it PoE on 10 and 100 but when it comes to 1000 you're stuffed....I've never actually come accross a gigabit PoE device before tbh. I'd be interested to hear how it works with the gigabit and PoE because as far as I know and am being taught...you can't do it.
GrumbleDook Posted October 11, 2007 Posted October 11, 2007 Surely it is all done by magic? I remember reading the instructions for use of TCP/IP over carrier pigeon ... that actually made sense.
webman Posted October 11, 2007 Posted October 11, 2007 I remember reading the instructions for use of TCP/IP over carrier pigeon ... that actually made sense. Would that be RFC1149?
localzuk Posted October 11, 2007 Posted October 11, 2007 Gigabit ethernet PoE works in roughly the same manner as phantom power on an amplifier to power mic's and electric guitars...
kylewilliamson Posted October 11, 2007 Posted October 11, 2007 There are a couple of types of PoE - theres the other that uses the spare wires, and i believe you can also piggyback with power over a different frequencey from data... you can also do it yourself!
Joedetic Posted October 12, 2007 Posted October 12, 2007 I suppose if you modulate your signal over the power that'd be how they do it. Requires a relatively high powered carrier signal i suppose...but, still interesting stuff whether i'm right or not lol
torledo Posted October 15, 2007 Posted October 15, 2007 I suppose if you modulate your signal over the power that'd be how they do it. Requires a relatively high powered carrier signal i suppose...but, still interesting stuff whether i'm right or not lol As far as I'm aware you can get gigabit midspans that allow you to use PoE and still attain gigabit speeds - not sure if this was just an IEEE task force setup to look into this or an actual product...if someone could shed some light on this ? tbh the only real need for gigabit speeds and PoE would be the newer gigabit wireless access points - even then 100mbps is plenty of uplink bandwith for most installations, gigabit IP telehony is not really required even for video telephony applications.
Guest Guest Posted October 15, 2007 Posted October 15, 2007 Oh yes ... second only to RFC1925!!! No matter how hard you push and no matter what the priority, you can't increase the speed of light. That reminds me of when our college IT teacher tryed telling me that "they are developing a medium faster than fibre optics" No matter how hard i tryed he just wouldnt accept that you cant get faster than the speed of light. What made it more bizarre is that he (sortof)understood the concept of a line being "wider" so that wasnt his mistake. My college experiance was a rather wasted time as you may have guessed.
webman Posted October 15, 2007 Posted October 15, 2007 Coax is thicker than fibre therefore you can get more data down it!!!!1
broc Posted October 15, 2007 Posted October 15, 2007 Oh yes ... second only to RFC1925!!! No matter how hard you push and no matter what the priority, you can't increase the speed of light. That reminds me of when our college IT teacher tryed telling me that "they are developing a medium faster than fibre optics" No matter how hard i tryed he just wouldnt accept that you cant get faster than the speed of light. What made it more bizarre is that he (sortof)understood the concept of a line being "wider" so that wasnt his mistake. My college experiance was a rather wasted time as you may have guessed. You can get optical multiplexers that carry multiple data signals concurrently over a single fibre, so in that respect you could get more data through a single fibre than you might think! We were using some very expensive multiplexed fibre links between a couple of mainframe sites on a project I worked on way back in 2000-2001. The multiplexer used difraction gratings at each end to merge/split the light. The box at each end cost £250k, the client had multiple multiplexers at both sites. The long term plan was to replace the difraction gratings with some form of silicon that would do the same job at a fraction of the cost......
GrumbleDook Posted October 15, 2007 Posted October 15, 2007 I've always found telepathy to be quickest ... unfortunately there is not a standard out there for it so I have to keep turning it off except for when I am at home.
torledo Posted October 16, 2007 Posted October 16, 2007 Oh yes ... second only to RFC1925!!! No matter how hard you push and no matter what the priority, you can't increase the speed of light. That reminds me of when our college IT teacher tryed telling me that "they are developing a medium faster than fibre optics" No matter how hard i tryed he just wouldnt accept that you cant get faster than the speed of light. What made it more bizarre is that he (sortof)understood the concept of a line being "wider" so that wasnt his mistake. My college experiance was a rather wasted time as you may have guessed. You can get optical multiplexers that carry multiple data signals concurrently over a single fibre, so in that respect you could get more data through a single fibre than you might think! We were using some very expensive multiplexed fibre links between a couple of mainframe sites on a project I worked on way back in 2000-2001. The multiplexer used difraction gratings at each end to merge/split the light. The box at each end cost £250k, the client had multiple multiplexers at both sites. The long term plan was to replace the difraction gratings with some form of silicon that would do the same job at a fraction of the cost...... add-drop multiplexers are used extensively in WAN backbones and with technologie ssuch as DWDM fibre service providers can utilise multiple wavelengths to support concurrent data streams on singlemode fibre. It's expensive and hi-tech gear but is essential in service provider MANs and WANs.
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