Small Business Switch (SG 300-10P) + Cisco IP Phone (7960) + PoE Issues

[brendancaulfield]

All,

I am testing out some of the small business switches for potential use in home setups.  I have recently received the SG 300-10P.  After some frustration, I got the switch setup the way I want it - with one exception.  I am trying to use a Cisco 7960 Series IP Phone via PoE but I can't seem to get power granted from the Switch.  When the phone is plugged in, all I see is the "Invalid Signature Counter" increasing.  Has anyone else ever had similar problems?  I am unable to find much documentation on this device so troubleshooting is a bit of a struggle.

Thanks in advance and let me know if I can provide further information.

-brendan

[jimmysands73_2]

Interesting, you are right, very little documentation on Cisco site.

I have never worked with the make/model, but a search of NetPro showed alot of post in the

NetPro > Small Business Support Community > Small Business Switches

for the same make/model of sw you have.

From browsing post, it looks like a config issue, but I can not find the exact answer on that group.

Found this also:

https://supportforums.cisco.com/servlet/JiveServlet/downloadBody/13573-102-1-31177/AppNote-addSx300-23sept.pdf

[brendancaulfield]

Thanks for your response.  I used the doc you linked to as a guide but I am still experiencing the same issue.  I will keep poking around (unless someone else has suggestions) and report back with my findings.

Thanks again,

-brendan

[jimmysands73_2]

I know you probably tried, but does it power up an AP (or anything for that matter)?

Here is the quick start guide:

http://www.cisco.com/en/US/docs/switches/lan/csbms/sf30x_sg30x/quick_start/ML/sf30x_sg30x_ML.pdf

And here is your administration gjuide....this should help out some.

http://www.cisco.com/en/US/docs/switches/lan/csbms/sf30x_sg30x/administration_guide/78-19308-01.pdf

Go to the section:

Managing Power-over-Ethernet Devices

Configuring PoE Properties

Good luck

[nickradaev]

For people who are still looking for an answer, SG 300 seems to support only PoE standard 802.3af, 7960 only supports cisco pre-standard PoE.

So there is a PoE comatibility issue.

Some people say that there is a workaround by simply reversing the polarity of 2 of the pairs of a cat5 wire. Havn't tried it yet and it seem to be risky.

[bts.forklift]

It looks like you're going to need a smart adapter. Panoptic Technology makes one and I think there's one by Ubiquity. Here's a link to the Panoptic site. http://www.panoptictechnology.com/network-smart-adapters/