Any cost efficient methods to get greater than 1Gbps transfers

[jgreco]

Well of course they work ...

Seriously, I'd expect the passive injectors to be just fine as long as they're used in the intended fashion.

They'll work right up to the point where you forget, unplug your PoE device, and plug in something else.

Then one of three things will happen:

1) Nothing will happen - desired ideal outcome that I think we probably agree is what SHOULD happen.

2) The PoE injector will be found to be a PoS injector, injecting some nonstandard voltage at some nonstandard wattage in some nonstandard pin configuration, and makes the magic smoke come out of the new device that wanted 802.3-af.

3) The new device will be discovered to be PoS compliant, maybe because someone thought it a good idea to ground all the "unused" ethernet pins, and suddenly many watts at significant voltage cruise through the connector and cabling, making magic smoke come out and ruining connectors and other things along the way, because cheap injectors often aren't fused.

There's probably other edge case options I've forgotten. Anyways, point is, passive injectors do exist and they're somewhat riskier. I would say there's less risk today than there was five or ten years ago because these days most stuff is 802.3-af, or at least you can GET 802.3-af stuff at a very modest incremental price, and that's just the smart smart smart way to go if you're doing more than a port or two. Consider that you can get a Netgear GS108PE (provides up to 4 port PoE) for like $90.

Years ago the options were crappier and you'd end up buying midspans (think: multiport injectors). I very much liked the PowerDsine PD-3504G since it actually does speak 802.3-af and isn't just blindly tossing watts down the line.

But these days it's just too much like work. The PoE standards keep ramping up for more watts and more wiring ->> suuuucks.

 

[rogerh]

May not be totally OT, but v. useful. Thanks.

 

[Bidule0hm]

My particular favorites are Cisco 7940/7960 phones which use "Cisco Inline Power" (pre-standard 802.3-af) which has the positive and negative power pairs reversed.

This is very good design practices, I love that :D

/irony

 

[jgreco]

This is very good design practices, I love that :D

In Cisco's defense, they get lots of stuff backwards. Look at the Yost serial standard. Cisco ... 100% backwards.

 

[rogerh]

BTW, for those worried about stray POE voltages, NICs should be tested to 1500v RMS and 2.4kV impulse (common mode, obviously), so POE should not do much harm. OTOH, not everything does what it is supposed to.

 

[jgreco]

BTW, for those worried about stray POE voltages, NICs should be tested to 1500v RMS and 2.4kV impulse (common mode, obviously), so POE should not do much harm. OTOH, not everything does what it is supposed to.

I once saw a T1 NIU hooked up by AT&T through an AT&T Systimax jack (what you'd consider a Cat5 jack these days) for a temporary site. You're never supposed to do that because the telco side of an NIU runs around 150V DC. I was very impressed to watch the jack incinerate itself (and the RJ45 plug) when it got a little wet one day. Damn, I cannot find the picture.

The amount of voltage and current offered by PoE should be ... "less" ... but do not confuse that for being totally safe. Some of the current implementations are pushing as much as 51 watts down the wire. That's a lot of energy. Think of a 40 watt lightbulb and how hot that gets.

 

[jgreco]

Perhaps you are right about Cisco switches in production environment, but can you guaranteed this will not happened with consumer grade Poe Switches that cost less than shipping empty box from china.

I don't understand the complete technology behind it , but I think we can't compare the results from a switches that cost about small car to switch that is cheaper than meal in MC Donald's.

How the hell did I totally miss the quoted message? Damn, that's *funny*!

 

[Black Ninja]

The way technology is going , soon there will be an option to charge you artificial heart by plug in to your poe switch. I wish good luck with the firmware to all early adopters.

On a serious side , there is another problem I hear which is even more likely to happen then total switch going crazy with PoE:
What they were talking about was about PoE protocol because is evolving with different versions , and when device negotiate PoE version with switch mistake can occur for what device support and what switch offer and as result switch can send the device to much voltage and damage the end device.

 

[jgreco]

The way technology is going , soon there will be an option to charge you artificial heart by plug in to your poe switch. I wish good luck with the firmware to all early adopters.

On a serious side , there is another problem I hear which is even more likely to happen then total switch going crazy with PoE:
What they were talking about was about PoE protocol because is evolving with different versions , and when device negotiate PoE version with switch mistake can occur for what device support and what switch offer and as result switch can send the device to much voltage and damage the end device.

That was a problem ten years ago. It isn't a problem today.

 

[Black Ninja]

That is very good to know. I am little behind I admin it.:p

 

[Black Ninja]

This is very good design practices, I love that :D

/irony

That's not related but , I wanted to ask you something. Because if I do remember correctly you are the electronics guy
My 10Gb nic has this part(the L5 part on the picture) chipped at the bottom , but seller insist is working fine. I dont know what this does so I can even tell how important it is. Can you tell ?

 

[jgreco]

Yeah, it's not great but it is probably not anything to make a big deal about.

 

[Black Ninja]

Probably you are right. But still would like to know. It's very common problem with this comportment on these cards.It's not the first one I have to return because of this

 

[jgreco]

Probably you are right. But still would like to know. It's very common problem with this comportment on these cards.It's not the first one I have to return because of this

It looks like it is some sort of SMT drum core coil, or inductor. As long as the coil itself isn't damaged, it's probably still functional. The surrounding material, since it is clearly a little brittle, appears to be ferrite material. The loss of this isn't a real great thing, but probably isn't catastrophic. I don't think you're going to "know" unless some Intel engineer in here and confirms how vital it is to have that operating in tip-top condition.

 

[Ericloewe]

They're sitting on some pretty massive traces, which suggests power delivery. It's hard to tell exactly what it's doing from the small area pictured. Inrush limiting doesn't make much sense on a PCI-e card, but maybe some DC-DC conversion on the other side of the board? There's not much cutting-edge stuff that runs off 3.3V these days.

 

[Black Ninja]

I don't think you're going to "know" unless some Intel engineer in here and confirms how vital it is to have that operating in tip-top condition.

Maybe there is one in the audience, and He will tell me more about how will it effect the card.:)
I wish I wasn't so pedantic, but that's the way I am for better or worst. I can't just shove it in a PC , if I got picture then is good enough and test is concluded - WORK. I then wonder why this or that is happening. You know what I mean.;)

P.S. From the way describe things in your postings I believe you do share my appreciation for neat work.

 

[Black Ninja]

Well this engineer may or may not show up. I'll go back to the switches non-POE:

A lot of us purchased dell 5548 based on jgreco recommendation and I am no exception. I can't think of better choice I could of make for Gigabit switch with 10Gb uplinks. I might even purchase another to get more Gigabit ports.

The only thing this switch is missing is redundant power supply and before I spend the money for RPS-720, which is not only option, I would like to ask if anybody has it , and share what is the power consumption of this thing and is there anything I should be aware by going this route for PSU redundancy.

P.S. Unit is not expensive , but it seems is made to feed 4 units , and I just wonder if will suck more power than the whole switch itself.

 

[jgreco]

Dunno about the RPS-720, but let me tell you, the RPS-600 is a watt-burning screamer. I wanna say I caught it jacking up the average power utilization of a 5324 from about 60W without RPS to more like 80W. Which I think may have been per switch, so it might require some substantial power budget and some hearing protection too. But it's been like 10 years since we put those into production so who knows whether my memory is hosed.

I just tossed an MPS-1000 (POE RPS for the Dell 7K's) on the bench and measured it without being attached to a switch and it was 10 watts.

So anyways if it turns out to be a heat or watt burn issue, bearing in mind I don't recall what the inside of the 720 looks like, the inside of the 600 is pretty straightforward:



Borrowed from the Internet 'cuz I don't have one to pull apart right now. But basically it's just four Delta PSU's. So whatcha do is you open up the can and disconnect three of them. The AC is the white and black wires at the front conspicuously wired up to the IEC inlet. Then every month you mail the $5.59 you saved in electricity to me, put "beer fund" in the memo, and make me slightly less grinchy.

 

[Bidule0hm]

Looks like a filtering inductor for a power rail as already suggested (the ceramic caps also confirm this) so it's not critical at all if the ferrite core miss 2 or 3 mm³ on it's end.

I'd buy the card but ask for a small discount because after all it's a damage so the card value isn't the same as the one of a perfect condition card.

 

[SirMaster]

Maybe if you beg the FreeNAS devs nicely, they will update Samba to 4.4.0 in the next FreeNAS build :)

Samba 4.4.0 supports SMB 3.0 multi-channel, so you can use multiple gigabit ports to transfer data at the aggregated speed of the number of gigabit ports you have connected.