Any ideas on testing a fibre through put/ speed

[tosca925]

We have a fibre connection that runs underground to another block, I have a feeling that the fibre has been damaged. We have two fibres pairs connected (one for redundancy) trouble is, as a pair they no longer work, can't even see any light down them when you shine a torch :-). We are currently using one fibre form each pair in the patch panel to keep us up and running.

I have pushed the KS3 software out to several rooms but the one at the end of the fibre has not picked it up. I am not sure if the data is not getting to this room at the speed it should.

Does any one know of a way I can test the speed/through put of the fibre or have nay ideas on the GPO deployment issue?


I have just gone to the GPO and redeployed the software to see it goes across for the next reboot.

[CyberNerd]

Sounds like a cable problem, you should be able to see light down the fibre with a torch - we had rats eat some of out cables and had similar symptoms.
first try pinging the machines to see if you get any loss, try 'ping -f' to flood the connection - any loss and check the cables:

You really need to test the fibre with a refactometer.
You should expect:
(0.5 dB x number of connectors) + (0.2 dB x number of splices) + Fibre loss on the total length of cable

If the loss is greater than 8 dB you'll start loosing data.
tcp will put a hold-down timer on lost packets so a small loss of packets mean *big* delays in transmision

[plexer]

get a local contractor to come in and test you may even be able to get it as a freebie if you ask them to quote on cost of replacement if it turns out to be damaged.

I just had some copper gigabit links tested free by the local company I use for structured cabling.

Ben

[apeo]

Adding to what CyberNerd said... you can add the switch -l and specify the send buffer size, sometimes you can only detect packet loss at higher packet sizes. Example use of switch:

Ping ipaddress -t -l 1500

[john]

No light at the end of the cable = bad, and in freqent cases, like mine, we had Rats in the ducts, not good, they made a bit of a mess, also dense cotnractors and diggers are quite annoying, and big tall waggons going under small bridges with fibres along the top of them, etc, basically its great stuff but too fragile.