Difference between revisions of "Telephone system:Cisco PoE hack"
(created Cisco CP-79x0 pre-standard PoE series hack cable) |
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Inspired from info at [http://www.voip-info.org/wiki/view/Cisco+POE voip-info.org], found it confusing, so I started testing myself.. | Inspired from info at [http://www.voip-info.org/wiki/view/Cisco+POE voip-info.org], found it confusing, so I started testing myself.. | ||
| − | + | === the stuff tested === | |
* [http://www.netgear.com/business/products/switches/smart-switches/smart-switches/GS110TP.aspx Netgear GS110TP] which turned out to be 802.3af type A (power on the data pairs) | * [http://www.netgear.com/business/products/switches/smart-switches/smart-switches/GS110TP.aspx Netgear GS110TP] which turned out to be 802.3af type A (power on the data pairs) | ||
* Cisco CP-7940 and CP-7960: known to be pre-standard PoE. | * Cisco CP-7940 and CP-7960: known to be pre-standard PoE. | ||
* 22k resistor | * 22k resistor | ||
| + | === what you need to do to build one === | ||
* Build an adapter cable that has a regular connector wired type B, and an outlet with the cables crimped on it the same (regular 'extension' cable, but can be very short) | * Build an adapter cable that has a regular connector wired type B, and an outlet with the cables crimped on it the same (regular 'extension' cable, but can be very short) | ||
* undo the outlet's cap carefully, keeping the wires in place | * undo the outlet's cap carefully, keeping the wires in place | ||
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* carefully place the cap back with the resistor leads joining the other wires | * carefully place the cap back with the resistor leads joining the other wires | ||
| + | === connecting it === | ||
Now, if you connect everything, '''the phone won't boot'''. It seems to be a kind of protection. | Now, if you connect everything, '''the phone won't boot'''. It seems to be a kind of protection. | ||
* leave the phone disconnected | * leave the phone disconnected | ||
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* when the PoE led lights up, plug it in to the CP-79x0 phone's switch socket: it should get power and start the boot sequence | * when the PoE led lights up, plug it in to the CP-79x0 phone's switch socket: it should get power and start the boot sequence | ||
| − | === | + | === tests === |
| − | When it didn't work, I tried to make a [http://hardwarebook.info/Ethernet_10/100/1000Base-T_and_100Base-T4_Crossover cross cable] (at least I think I did, I have to verify), but that didn't seem to work either: it triggered power, but the phone did nothing (probably thanks to a reversed polarity protection diode). | + | When at first it didn't work, I tried to make a [http://hardwarebook.info/Ethernet_10/100/1000Base-T_and_100Base-T4_Crossover cross cable] (at least I think I did, I have to verify the spare pair ordering), but that didn't seem to work either: it triggered power on the switch, but the phone did nothing (probably thanks to a reversed polarity protection diode). |
Then, when I plugged in the straight cable without phone, it booted; so I took a gamble and plugged the powered rj45, and it worked. | Then, when I plugged in the straight cable without phone, it booted; so I took a gamble and plugged the powered rj45, and it worked. | ||
| − | After testing, the actual network seems to work fine | + | After testing, the actual network seems to work fine (tested with 3m cable) |
Revision as of 21:49, 8 July 2013
Inspired from info at voip-info.org, found it confusing, so I started testing myself..
the stuff tested
- Netgear GS110TP which turned out to be 802.3af type A (power on the data pairs)
- Cisco CP-7940 and CP-7960: known to be pre-standard PoE.
- 22k resistor
what you need to do to build one
- Build an adapter cable that has a regular connector wired type B, and an outlet with the cables crimped on it the same (regular 'extension' cable, but can be very short)
- undo the outlet's cap carefully, keeping the wires in place
- use S-39 on the 'forks' for pin 1 and 3 (white-orange and white-green).
careful that you have the ordering correct: outlets order pins by color pairs.
the S-39 is for the forks to quickly get tinned without destroying the insulation - be sure the leads of the resistor are slightly shortened, so that it will just pop out of the outlet at the back.
- solder it!
- carefully place the cap back with the resistor leads joining the other wires
connecting it
Now, if you connect everything, the phone won't boot. It seems to be a kind of protection.
- leave the phone disconnected
- connect a regular network cable to the switch of your desired length
- connect the adapter's outlet to the cable and wait (at most 5 seconds)
- when the PoE led lights up, plug it in to the CP-79x0 phone's switch socket: it should get power and start the boot sequence
tests
When at first it didn't work, I tried to make a cross cable (at least I think I did, I have to verify the spare pair ordering), but that didn't seem to work either: it triggered power on the switch, but the phone did nothing (probably thanks to a reversed polarity protection diode).
Then, when I plugged in the straight cable without phone, it booted; so I took a gamble and plugged the powered rj45, and it worked.
After testing, the actual network seems to work fine (tested with 3m cable)
