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Why no power over ethernet ?

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1 hour ago, ThingEngineer said:

Hak5 Packet Squirrel POE Upgrade

Nice work! Pretty sweet mod. Can it take input voltage up to 48V? does it regulate down?

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1 minute ago, Just_a_User said:

Nice work! Pretty sweet mod. Can it take input voltage up to 48V? does it regulate down?

Thank you! I'm just about done with the Instructable so you'll get all the details there. But to answer your question, yes it "steps-down" 48 volts input on the spare pairs (4/5 blue & 7/8 brown). That is what it's doing in the video, I should have included a voltmeter to show that.

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On 11/1/2017 at 5:38 AM, duan said:

Hi, just a little question, why do you use USB 5v as power input since it could be done by the ethernet ? (better way for standalone)

Whatever the reason forget about it, just do it yourself. ;)

Instructable: https://www.instructables.com/id/Hak5-Packet-Squirrel-POE-Upgrade-Mod

 

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2 hours ago, ThingEngineer said:

48 volts input on the spare pairs

Just checked out your breakdown, its a really nice mod. The buck converter you referenced isnt good for 48-50V it states Input voltage: 4.5 V to 28 V. Is that board exactly what you used in your mod? If it is, then its good for some but not all POE systems.  But still really nice to fit everything into the small package, The dc-dc buck converters seem to get way larger when accepting higher input voltages so I doubt they would fit so easily and would probably contribute more heat to the enclosure.

 

Edited by Just_a_User

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Just now, Just_a_User said:

Just checked out your breakdown. The buck converter you referenced isnt good for 48-50V it states Input voltage: 4.5 V to 28 V.

Is that board exactly what you used in your mod?

 

I talk about that in both the instructable and in the full video. Yes, that is the "advertised" rating and yes that is what I used anyway.

The chip is rated at +30 volts in but I did a destructive test on one, it doesn't fail until the input voltage goes above 70 volts. With such a small load on the output thermal dissipation and failure isn't an issue. Looking at the signals on the board it does a nice job at chopping the higher voltage. And since the internal high-side high voltage power MOSFET is apparently rated at or above 60V it works just fine at 48V. I've had it running for a couple days now with no issues. I suspect the internal regulator is what failed and not the MOSFET.

If you find a similar regulator or step-down converter rated for +48V input of comparable size you can use that.

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27 minutes ago, Just_a_User said:

Just checked out your breakdown. The buck converter you referenced isnt good for 48-50V it states Input voltage: 4.5 V to 28 V.

Is that board exactly what you used in your mod?

 

You could use something like this instead.

https://www.mouser.com/ProductDetail/Murata-Power-Solutions/NCS3S4805SC/?qs=sGAEpiMZZMtz8P%2feuiupScznIAMLQa8KIRu89kF5ZBQ%3d

 

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3 minutes ago, ThingEngineer said:

it doesn't fail until the input voltage goes above 70 volts

that's really good info.

3 minutes ago, ThingEngineer said:

I've had it running for a couple days now with no issues

that's double good info :)

Thanks for your hard work its a really nice mod!

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@ThingEngineer the mod is nice.


But i can see some problems with it. that are probably going to kill the PS or even the network equipment.
I don't have any schematics of the PS but if the Ethernet jacks are terminated according to the IEEE standards then it will not like the POE voltage on it.
The "bob smith" termination needs to be change to handle the POE DC power. 
With the standard termination getting POE it will apply the power to the data pairs to and there will run a high current trough those termination resistors.
These resistors are 75 ohm. with 2 of them in series you get 150 ohm. with the POE of 48V you have a current of 320mA (48V/150 ohm) running trough it and its not design to handle this.
There is around 15watt (48v*0.32ma) running trough these resistors.

Then you pass the POE from one side to the other side. beside screwing up the termination of these pairs any gigabit switch will see the PS and the device you put in your PS. this can screw up the ethernet signaling (the network checking for a 1000mb or 100mb connection and data packets that may be send).

You also don't have a POE PD controller so a standard POE compliant switch/injector will never give power because it can't sense the POE signature of the PD controller.
A cheap injector that has always supply power on mode B may work. but i would not trust it and the mod to work long or perfect.

Here is some good info about how to design a POE PD en POE PSE.
http://www.ti.com/lit/an/snoa464c/snoa464c.pdf
http://www.onsemi.com/pub/Collateral/EVBUM2156-D.PDF

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Whilst not a technical document I found this useful to compare various manufacturers & standards POE pinout's.

http://pinoutguide.com/Net/poe_pinout.shtml

A surprising amount of variation, I'm unsure that a "one size fits all" solution would be possible in a small(ish) package like the PacketSquirrel.

BUT you could always carry something like this and use it before plugging in http://a.co/52dIVY2

Edited by Just_a_User

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@Just_a_User yea there are some different standards out there. but the 802.3at and 802.3af are IEEE standards that are world wide. and any POE compliant system would use this.
So any POE you will come across in the field i am 90% sure it will be a 802.3at/af version. 
The only systems that will use something different are the old CISCO POE systems. those a proprietary and are not used in new CISCO switches any more.

ubiquiti does have a 24v poe proprietary products beside the standard POE products. and because ubiquiti is pretty populair this might be a system you want to support on the PS. but you will have a different setup for supporting the 24V poe.

I bought one of these to test out.
https://www.aliexpress.com/item/Max90-Operating-Humidity-The-802-3af-802-at-PoE-Tester-connected-to-an-RJ45-outlet-to/32805864045.html

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On 11/12/2017 at 8:24 PM, killergeek said:

But i can see some problems with it. that are probably going to kill the PS or even the network equipment.
I don't have any schematics of the PS but if the Ethernet jacks are terminated according to the IEEE standards then it will not like the POE voltage on it.
The "bob smith" termination needs to be change to handle the POE DC power. 

4

Thank you for bringing this up! Your concerns are mostly correct, this mod is very situational and I left out some of that detail. I added a section to the Instructable (Step 1) called understanding POE to explain that. In my case I wanted it to work behind a midspan POE injector, the injector breaks the path from pairs 4/5 & 7/8 to the router so it will not see the bridging of the pairs. And since the injector also bridges those pairs (Mode B) it does not matter that we are bridging them again in the packet squirrel.

On 11/12/2017 at 8:24 PM, killergeek said:

With the standard termination getting POE it will apply the power to the data pairs to and there will run a high current trough those termination resistors.
These resistors are 75 ohm. with 2 of them in series you get 150 ohm. with the POE of 48V you have a current of 320mA (48V/150 ohm) running trough it and its not design to handle this.
There is around 15watt (48v*0.32ma) running trough these resistors.

If I am understanding you correctly you are saying that if we have Mode A power present on the data pairs (1/2 & 3/6) the termination resistors in the Packet Squirrel will draw too much. The problem with this assumption is that the Packet Squirrel does not terminate the tap (center pin) on the network transformer, it's floating. And we wanted to make the Packet Squirrel work off Mode A power I would not want to terminate it anyway. The PD would do the termination, we would just tap 48 volts off the network transformer. I talk about this in the new Instructable section as well. Did I understand you correctly on this issue?

On 11/12/2017 at 8:24 PM, killergeek said:

Then you pass the POE from one side to the other side. beside screwing up the termination of these pairs any gigabit switch will see the PS and the device you put in your PS. this can screw up the ethernet signaling (the network checking for a 1000mb or 100mb connection and data packets that may be send).

See the first explanation regarding the Mode B midspan POE injector.

On 11/12/2017 at 8:24 PM, killergeek said:

You also don't have a POE PD controller so a standard POE compliant switch/injector will never give power because it can't sense the POE signature of the PD controller.
A cheap injector that has always supply power on mode B may work. but i would not trust it and the mod to work long or perfect.

We would only want a POE PD controller if the target device was not a PD and we wanted to activate the PSE or if there was no target device and we were just on an empty port and wanted POE. Neither of these were my case. SO MANY situations, I completely understand why Hak5 left out POE now lol.

I don't want the Packet Squirrel to be a compliant POE PD. It's already a covert man-in-the-middle device. Why would I want it to say, "Hey Mr. Network Switch, could I get some nuts please?" Nope, I want it to be a quite little parasitic squirrel drawing just enough power to get by while not interfering with the typical operation of whatever PD is on the target side.

20 hours ago, Just_a_User said:

A surprising amount of variation, I'm unsure that a "one size fits all" solution would be possible in a small(ish) package like the PacketSquirrel.

Exactly! And that is the real reason (I believe) POE was left out. If I was going to complain about something it wouldn't' be the lack of POE it would be that it forces the target to negotiate down to 10/100Base-T. But again I understand, two more network transformers and other components for 1000Base-T would add quite a bit to the component count and therefore the footprint. 

18 hours ago, RazerBlade said:

Nice that you have showed it was possible even in such a small formfactor despite what Hak5 said!

Thank you! But technically I didn't fit it in the case. ;) 

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If you really need POE the external option suggested by @Darren Kitchen and others is really the best choice. There are just too many possible scenarios. I really just did this for fun to see if I could.

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@ThingEngineer if you look at this design you can see that the transformer is terminated and the 2 unused pairs.
but if they used a different design then my info is invalid.

ether1.png

 

9 hours ago, ThingEngineer said:
On 13-11-2017 at 3:24 AM, killergeek said:

You also don't have a POE PD controller so a standard POE compliant switch/injector will never give power because it can't sense the POE signature of the PD controller.
A cheap injector that has always supply power on mode B may work. but i would not trust it and the mod to work long or perfect.

We would only want a POE PD controller if the target device was not a PD and we wanted to activate the PSE or if there was no target device and we were just on an empty port and wanted POE. Neither of these were my case. SO MANY situations, I completely understand why Hak5 left out POE now lol.

I don't want the Packet Squirrel to be a compliant POE PD. It's already a covert man-in-the-middle device. Why would I want it to say, "Hey Mr. Network Switch, could I get some nuts please?" Nope, I want it to be a quite little parasitic squirrel drawing just enough power to get by while not interfering with the typical operation of whatever PD is on the target side.

On 13-11-2017 at 9:02 AM, Just_a_User said:

A surprising amount of variation, I'm unsure that a "one size fits all" solution would be possible in a small(ish) package like the PacketSquirrel.

Exactly! And that is the real reason (I believe) POE was left out. If I was going to complain about something it wouldn't' be the lack of POE it would be that it forces the target to negotiate down to 10/100Base-T. But again I understand, two more network transformers and other components for 1000Base-T would add quite a bit to the component count and therefore the footprint. 

And yea i agree with you the hassle to support POE. but it may be a nice idea to make a add-on for the PS. 
the add-on with the function of a POE extender and tapping the PS in between the data.
So the switch will see a POE device and power it, but the data is flowing trough the PS.

most of the POE extenders are just Ethernet extenders that make it be able to extend to 200m instead of the 100m specified by the IEEE standard and keep the POE function working.

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PoE devices and the Packet Squirrel tcpdump payload sorted for me...a happy bunny squirrel.

 

Didn't want to modify the squirrel itself, but wanted to capture packets for a PoE phone without needing extra power sockets.

The squirrel doesn't need to be inline with the phone to do this - it just needs the packets sent to it.

I looked for a PoE powered, managed switch with PoE pass-through and port mirroring & found the Netgear GS105PE.  Others probably exist, but its the first one I came across.

image.png.8e8a2f1fc93a9cc1d8fe690abecb5d7c.png

 

The PoE switch powers the GS105PE, which powers the phone.  I did try a PoE splitter to power the PS from the 2nd PSE port on the GS105PE as well, but the Netgear wouldn't power both at the same time.  So I just stuck with the USB battery pack I use for the PS anyway. 

I set the phone port to 100Mbps to match the PS speed, mirrored port 1 to port 3, plugged it all in, powered up the PS and got all the packets.

At £50 it kinda doubles the cost of the PS and at 6"x4" its about the same size as a couple of battery packs.

But it does the job without modding the PS and without needing another power socket close by or a separate injector or PoE splitter.  Configure it once then plug and play.

 

 

 

 

 

 

 

 

Edited by Niceday

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Someone has indeed already done it properly, but I think using a PoE-to-Data+USB should work fine. :)

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@Niceday if you look at the manual of the GS105PE. it says "POE pass-thru: 19W with 802.3at/7.9W with 802.3af input power" so depending on what power is supplied and what is taken by the phone explains why you are not able to also supply the PS+splitter with POE.

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