Trouble with PoE using a Linksys srw2024p switch

[poiZin]

I hooked up a Linksys srw2024p to our network today, as it is able to supply Power over ethernet to networked devices. The switch is now hooked up, we are on the internet and LAN, but when I plug the ethernet cable into a phone, I get no power. I still only get power when using the special ethernet cable polycom supplied with the power injector on it. I dont want to use the power injector cable, I just want to use a regular cat5 to provide power to my phones.

Does anyone know if there is something I have to do to get this to work? Possibly something in the switches config? Which by the way I cant access through the web interface (i think its because I have a DLINK router ATM but Im not sure).

Any help would be much appreciated,

Thanks in advance!

 

[jlazzaro]

what model polycom? are you sure it supports 802.3af? your router has nothing to do with accessing your switch's web management interface...

 

[spidey07]

Seconded - make sure the switch and phone support 802.3af and you have category rated cabling. That means all 4 pairs are connected and wired properly and in spec.

 

[drebo]

From what I remember, that switch is fairly weak as far as its PoE capabilities go. While it is true that many phones do not actually pull the full 15.4W specified in 802.3af, some of the Polycom phones will get close to it. The IP 550s, for instance, are a pretty big power draw. If they're IP 650s with backlit sidecars running SIP 3.0...well, you can only imagine.

Also, from what I remember using one of those, they default PoE to off on all switch ports. You'll need to figure out how to get to the web interface and verify. Some switches will default to an "unmanaged" state, and require coaxing to get it into "managed" mode. Depending on the switch, it may pick up a DHCP lease (Look@Lan may be helpful if your DHCP server is less than descriptive), or it may have a specified default IP address. You'll have to read the manual to figure that out, but it's usually a simple process.

Edit: looked it up, 12 ports PoE, 180W total. YMMV.

Edit 2: Also, depending on your phone, it may not have PoE capabilities. We'd need your phone model to verify that. The IP 4XX and the 3XX series come to mind. Perhaps even the IP 501 as well.

 

[poiZin]

It is a PolyCom IP 501 SIP which does support PoE. It is Cat5 cable, which also supports PoE, and all 4 twisted pairs are connected using the scheme: White and orange, orange, white and green, blue, white and blue, green, white and brown, brown.

I know in general my router has nothing to do with the web interface for my cisco switch, what I mean is that the default address for the cisco is 192.168.1.254, and since I am using a DLINK router, the local network is 192.168.0.x as opposed to .1.x. Thus, I tried the address 192.168.0.254 as well and still not able to interface with the switch.

Edit: I also connected a linksys router today to make the local ips .1.x in case the linksys product is address fussy, but no dice on that either.

 

[imagoon]

Why not patch in to the switch, hard set the Windows IP address, connect and change the switch IP address?

EDIT:

That switch appears to have a console port, console in to it and change the ip.

 

[drebo]

I was right -- the Polycom 501 does NOT support standard 802.3af power over ethernet. You need a special patch cable to make it work.

You'll need this cable to make it work: http://www.voiplink.com/Polyco.../polycom-poe-cable.htm

From what I've read, depending on the phone you ordered, the Polycom Inline Power cable (the one that's a CAT5 cable with a DC input jack on it) MIGHT work in the same manner as the above cable. Might want to try that before you order something.

However, for the Polycom 501, you cannot simply use standard patch cables.

 

[poiZin]

Originally posted by: drebo
I was right -- the Polycom 501 does NOT support standard 802.3af power over ethernet. You need a special patch cable to make it work.

You'll need this cable to make it work: http://www.voiplink.com/Polyco.../polycom-poe-cable.htm

From what I've read, depending on the phone you ordered, the Polycom Inline Power cable (the one that's a CAT5 cable with a DC input jack on it) MIGHT work in the same manner as the above cable. Might want to try that before you order something.

However, for the Polycom 501, you cannot simply use standard patch cables.

--
Ah. That makes sense. Thanks so much for your help, I was starting to go nuts about this because my boss has been stressing that he wants this PoE up asap. Much appreciated. I do have another question for you, though. This cable, is that bulk part on it power injector, where you plug from AC to the ethernet cable, or is nothing required to plug into it to make it compatible?

Basically, is what is shown in the picture of the cable all I need (no power injector)? If a power injector is still needed I will have to get some better phones, and if so any suggestions on a similiar price range that supports the 802.3af without injectors? It doesnt have to be PolyCom btw.

 

[poiZin]

Also - I am still ahving trouble logging into the web interface of the cisco switch. I also did try the console port, serial connection and using hyperterminal to connect, however it did not detect any interaction with the switch, even through direct console. I used a cisco scanner to scan the local network to try and detect a possible ip of this switch, and no luck with that either. It seems no matter what I try I can not connect to this darn switch to configure it.

The way it says to reset it is to leave it unplugged and plug it back in, which I did after 2 minutes and I can tell it went through a reset with the no lights for a while, then all came on flashing.

How can I completely clear out this switch so that I can log into it through the web interface @ the address of 192.168.1.254?

 

[drebo]

Originally posted by: poiZin
--
Ah. That makes sense. Thanks so much for your help, I was starting to go nuts about this because my boss has been stressing that he wants this PoE up asap. Much appreciated. I do have another question for you, though. This cable, is that bulk part on it power injector, where you plug from AC to the ethernet cable, or is nothing required to plug into it to make it compatible?

Basically, is what is shown in the picture of the cable all I need (no power injector)? If a power injector is still needed I will have to get some better phones, and if so any suggestions on a similiar price range that supports the 802.3af without injectors? It doesnt have to be PolyCom btw.

The cable in the picture does NOT require anything but an 802.3af power source. It does not need the stand-alone power injector. That cable is designed to take 802.3af and turn it in to the Polycom proprietary format.

The newer Polycom phones (the 550 and 650) do support standard 802.3af. There are a number of other cheap phones out there that do as well, however, none of them have the quality of the Polycom IP 501. The 501 is a great and very usable desk phone. Obviously, the 550 is vastly improved, but it's also fairly expensive. I would recommend staying away from Grandstream, Snom, Linksys, and Aastra, as they're pretty crappy. The Polycom 430 is about the same price as a 501 and does support 802.3af, but it's surely not as nice.

I would stay away from the Cisco phones, even though the 7940 is cheap. The switch you have will not properly power them, even with the reverse-polarity dongle. And if you're using Asterisk, the 7912 has a TERRIBLE SIP image that doesn't play nice at all.

Honestly, the 430 and the 501 are your best options. If you already have the 501s, you'll probably just want to get the cable I linked to before. Polycom and Cisco make very good IP phones.

Now, if you're feeling spendy, Mitel makes some phones that have SunRay thin clients built in to them...now those were slick. Smart card tells the phone what your terminal session is as well as what your extension is. Also, Adtran has started making IP phones...I only saw them at Interop this year and only for a brief time, but they seemed interesting.

As far as phones go, though, I have a preference to Polycom and Cisco. The Cisco 7941s are pretty interesting, but a bit more difficult to get to work. I'd stay away from anything in the 7905/11/12 way. And if you need cordless, don't waste money on the Snom M3...buy a Linksys PAP2T and a $30 cordless phone from Staples. The M3 is neet, but not worth the expense when any standard analog cordless phone has all the same features (at least I can mimic all of the features in Asterisk, anyway, with * codes).

Ok, no more rambling from me.