s you assume best-cast scenarios, 60 km is a stretch.
Frank
-Original Message-
From: Mikael Abrahamsson [mailto:swm...@swm.pp.se]
Sent: Thursday, September 08, 2016 1:36 PM
To: Frank Bulk
Cc: nanog@nanog.org
Subject: Re: Optical transceiver question
On Wed, 7 Sep 2016, Frank Bulk wrote:
On Wed, 7 Sep 2016, Frank Bulk wrote:
Is it an industry practice to market distance based on the hot optics,
not on the worst case, which is minimum TX power?
No. If this is 1310nm optics with 0.4dB/km budget, the budget figure
should be end-of-life figure, ie worst case according to the spec
The typical situation of the vendor is that the link-budget of the
transceiver considers the worst scenario for TX and loss of dBs generated
by time of operation of the laser, standard attenuation of the fiber, how
it changes in how old it is,... in other ways, the calc ispessimistic.
In my experi
Frank Bulk wrote:
> We recently purchased some generic optics from a reputable reseller that
> were marketed to reach 60 km.
transceivers don't work like that. They are sold with a specific
optical budget, normally rated in dB at a specific wavelength. The km
equivalent is usually based on G.652
nke; nanog@nanog.org list
Subject: RE: Optical transceiver question
Not buying fresh veggies here... All optics have about a 5 db range that the
vendor will say it is good. The better venders stamp the output power on the
optics but not all do this... What he said is to achieve the 60 Km sell
It's a bit like car fuel efficiency values, even with reputable brands :)
In this industry, the number of kms for such optics is a best case
approximation of the combination of (most notably) those elements:
worst case power budget, capability to deal with chromatic scattering on this
length wit
Subject: Re: Optical transceiver question
What you're saying is if you purchase ten identical optics with the same SKU,
and put them on a few hundred meters of coiled SC/UPC to SC/UPC simplex fiber
and an optical power meter on the other end, they're showing varying real world
Tx powers fr
We have seen cases where the patches introduce enough loss to cause a lot of
loss. Have you done an OTDR on each link?
Jared Mauch
> On Sep 7, 2016, at 4:23 PM, Frank Bulk wrote:
>
> We recently purchased some generic optics from a reputable reseller that
> were marketed to reach 60 km.
>
> B
What you're saying is if you purchase ten identical optics with the same
SKU, and put them on a few hundred meters of coiled SC/UPC to SC/UPC
simplex fiber and an optical power meter on the other end, they're showing
varying real world Tx powers from between +0 to +5dBm?
That's not right at all, t
We recently purchased some generic optics from a reputable reseller that
were marketed to reach 60 km.
But what we found, based on the spec sheets, is that it could only reach
that distance if the optics were transmitting on the high side of the
transmit power range.
For example, if the TX range
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