Wireless Networks Thread, Netgear GSM7224 + AGM731F Module in Technical; Hi Guys,
Little panicked here.
I just purchased a new switch and intended to replace the fibre switch that is ...
21st January 2010, 05:41 PM #1
Netgear GSM7224 + AGM731F Module
Little panicked here.
I just purchased a new switch and intended to replace the fibre switch that is old and unreliable with a GSM7224 and some fibre modules. I have 2 so I intend to replace the backbone and then over time add some more. I have installed 4 modules in the switch ready to do the switch over.
I currently only have one patch cable so I just tried it to test it but the module doesn't light up.. neither does any of them.
I hoped it would just be a switchover but now I am worried I haven't researched enough. I havew tried the fibre patch cable each way round.. I am wondering if its broken.
The GSM7224 says the modules just plug in, which they did.
Anyone use them and do they just plug in and work?
I did intend to update the firmware but for some reason it hates me and won't over HTTP.
21st January 2010, 06:58 PM #2
Upgrade the firmware, IIRC you'll need to use tftp to update it. Pumpkin is decent pumpkin
Make sure they're seated correctly and test with a known good fibre patch lead.
We have a couple of 7224s and a 7248 and the AGM-731F modules. Had no problems with either and nothing out of the ordinary required to make the modules work.
21st January 2010, 07:32 PM #3
A stupid question but.... what are you connecting them to?
1. Is the module at the other end Gigabit?
2. Is the module at the other end 850 or 1300 nm?
You never said, and you wouldn't be the first person to try and connect a gigabit module to a 100mb one!
21st January 2010, 07:41 PM #4
First thing I would do is check in the switch web managment to make sure they all show up alright and as above fo a firmware update to make sure the switch can interface with them properly.
After that a few things I would check (that you have probably covered):
make sure the TX/RX pairs are around the right ways, some cable monkeys get them switched causing issues.
If it is a SX module check that the little red light is present on the TX side of the module, if it is LX do not look directly at it!! as it will damage your eyesight and you may not be able to see it anyway due to the wavelength. Use a cellphone cammera to look at the end which will pickup infrared laser light and protect your eyes while allowing you to check.
Make sure the patch lead is the same fibre type ie 62.5 or 50 micron as mixing types does not work.
Make sure the modules are compatible with the ones at the other end of the link ie both 1GB and both SX or both LX. If it is a transciver at the other end or an older module you may need to reset it at the far end while the new module is connected to nefotiate the connection.
Make sure the ports are not disabled in the switch interface.
Reset the switch to make it run diagnostics and see if the modules report an error.
21st January 2010, 09:32 PM #5
Thanks for all this guys, will have to wait till I get another patch cable to check it out.
I have no idea what the fibre is going into the terminal, does my patch have to match that? its a 25 core fibre running between two buildings.
Suppose the easiest way is to check what the existing patch cables are and hope I got the same.
Knew I should have researched a bit more.
22nd January 2010, 01:03 AM #6
- Rep Power
The fibre spec will be printed on the outside of the cable jacket, something like 62.5/125 or 50/125 so you should just be able to look round the back of your patch panels.
Originally Posted by Simcfc73
22nd January 2010, 09:33 AM #7
Think I must have checked it ages ago cos it all matches.
24 core Internal/External 62.5/125 Multimode Fibre for the backbone
and the existing patch cables are
1m ST-SC MM 62.5u Duplex Yellow Fibre Optic Cable (old switch has SC connectors)
which I am replacing with
Belkin LC / ST Multimode 62.5/125 um Duplex Fibre Patch Cable 1m Length
Now I only replaced one end of the fibre so will try it at both ends next.
PS. Did notice the duplex vs multimode thing also which won't help I suppose.
22nd January 2010, 09:42 AM #8
- Rep Power
It could be something like the send and receive pair are swapped over, I had an old D-Link switch that had this on it and it puzzled me till i realised it was trying to use one cable of the pair and transmitting down that one optic.
I would look at the fibre module with no cable in and see what side the light is coming from. And do the same with the cable, these light should be on opposite sides from each other. The safest way to do this would be use a piece of paper in the dark and hold it in front of the fibre module and see if you can see it, then do the same with the patch cable end that plugs into the switch.
DISCLAIMER - laser light can be damaging to eyesight, don't look straight into it.
25th January 2010, 10:07 AM #9
Tested it with just a the new switches and modules at each end and it works fine. i guess that I can't mix and match Looks like I will need to replace all the other switches to gain the benefit of using these tidy modules.
25th January 2010, 11:11 AM #10
- Rep Power
It was mentioned earlier but I didn't see a reply - are both ends of the proposed link gigabit capable? The GBICs on each end won't (can't) switch speed as would be possible with gigabit on copper.
30th January 2010, 01:30 PM #11
BUMP - @Simcfc73
Originally Posted by james_yale
Would be nice to know what the outcome was. People use these threads as a source of inspiration.
30th January 2010, 02:12 PM #12
Sorry been playing with my new server
It works with the same module at each end, I intended to try and get all the fibre working through these switches but it looks like I will have to wait and purchase new switches over the coming years. The fibre convertor at one end was only 100mb which i why i didn't work.
I have a FSM726 at another location which takes fibre so I have bought a different GBIC module that fits in their to see if I can gigabit that link too.
I haven't fully switched over as I am waitign for half term.
30th January 2010, 06:13 PM #13
That's what we needed to know...
Originally Posted by Simcfc73
You are not the first and will not be the last, but others here will learn from your mistake and thats whats important.
So to get your self out of trouble and help roll your Gigabit switches why not buy a really cheapo gigabit media converter to replace your old 100mb unit?
Mini5 and Level One do some with SC Gigabit Fiber in 10/100/1000 Autoneg copper out for around £150
Once you have started to roll out your Gigabit backbone having one of these around will be useful anyway and they are a handy test rig to have in the tool bag along with a laser pointer and a few different patch leads.
31st January 2010, 06:22 PM #14
You can pick up "generic" modules for your netgear switches from the likes of hardware.com. Agilent AGM731F's are £50, whereas the "real deal" prosafe ones are about £150. I have these agilent ones all over the shop and they work fine, saved a packet too.
Thanks to Oops_my_bad from:
31st January 2010, 08:02 PM #15
I would recommend some caution when selecting and using "generic" modules.
Originally Posted by Oops_my_bad
For quite a while now some switch manufacturers have taken to disabling "generic" modules during firmware updates.
HP and Cisco do this to deter users from buying other inferior "OEM" GBic modules.
We all know that these are all made by the same suppliers such as Agilent, Finnstar etc but by coding the eeproms in the SFP's they can now decide which ones they allow to work in their kit!
So you could save yourself some serious cash initially then find that an essential update knocks out your cheap modules.
This has happened to me after an HP Warranty swap out, the firmware on the replacement switch immediately detected the non HP SFP's and refused to pass packets through them!
With no firmware rollback available I had to fork out for 4 new HP ones!
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