CWDM question

Christopher Costa ccosta at gaikai.com
Fri Dec 13 03:31:13 UTC 2013


If you're also doing 1310 does that mean there's a splitter cable inline
with the passive mux? If so, some are cheap and don't filter well outside
of the 1550 band.
On Dec 12, 2013 10:23 PM, "Keith" <kwoody at citywest.ca> wrote:

> That is whats next. They took down the whole fiber instead of just the
> 1471 wave to test
> which killed transit...grrr..
>
> They say their tx/rx are within spec.
>
> Next is jumpers and sfp swaps I guess.
>
> Thanks.
> On 12/12/2013 6:40 PM, Sam Roche wrote:
>
>> If you have a CWDM optical power meter and light source, see if you can
>> measure the power level on the receiving end and verify that it is within
>> the spec of the SFP. Maybe it is a bad jumper or port on the 1471 receive
>> on their end or send on your end.
>>
>> If the two switches can be brought to the same location, you might also
>> want to connect them together using short jumpers, but make sure you have a
>> power meter to ensure you use the proper attenuators to avoid burning out
>> your optics. This would rule out your fiber and mux in case it an issue
>> with an appliance or SFP. I've had CWDM SFPs burn out for no apparent
>> reason twice now.
>>
>> *From: *Keith
>> *Sent: *Thursday, December 12, 2013 8:11 PM
>> *To: *nanog at nanog.org
>> *Subject: *CWDM question
>>
>>
>> CWDM question
>>
>> Hi.
>>
>> We are doing a fiber link between us and another SP using CWDM.
>>
>> There is traffic flowing just fine at the 1310 wave, and have recently
>> added a
>> 1471 wave.
>>
>> On the 1471 wave there are some problems with it. From our perspective,
>> and we
>> have packet captured this, we are transmitting data to them, but they say
>> they
>> are not seeing anything. We are receiving from them, and while we show
>> that
>> packets are leaving our interface to them, they are getting nothing at
>> all.
>>
>> There are good light levels between the two locations and do not
>> understand
>> why they are not seeing traffic from us even though we are sending it.
>> Our packet
>> counters show we are transmitting to them and receiving from them.
>>
>> Is it possible to have RX and TX light and things appear to be ok, but
>> have the
>> RX on their side fubar in some way that it is not operating correctly in
>> that our
>> traffic is not reaching them?
>>
>> Thanks.
>>
>>
>>
>>
>>
>>
>>
>>
>
>


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