[38574] in North American Network Operators' Group
RE: POS OC48 interfaces using different wave length
daemon@ATHENA.MIT.EDU (pasi.vaananen@nokia.com)
Thu Jun 7 13:29:50 2001
Message-ID: <B9CFA6CE8FFDD211A1FB0008C7894E460379E9F7@bseis01nok>
From: pasi.vaananen@nokia.com
To: web@typo.org, simonl@rd.bbc.co.uk
Cc: vgi@opentransit.net, nanog@nanog.org
Date: Thu, 7 Jun 2001 12:28:30 -0500
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Errors-To: owner-nanog-outgoing@merit.edu
> >I am thinking about using different POS interfaces on dark-fibers.
> >
> >On one side, i already have POS-OC48-LR card (Cisco).
> >This card use 1550 nm wave length.
> >
> >We would like to use a POS-OC48-SR (Cisco).
> >This card use 1310 nm wave length.
> >
> >Are 1310 and 1550 optics comptatible ?
>
> You have to have the same wavelength at both ends, otherwise it won't
work.
>
> >If yes, i guess that there is impact on the power Budget available.
How-Much ?!
>
> LR tends to be 1550nm, because 1550nm has less signal loss over the same
> length of fiber.
>
The receivers are typically wideband, and can receive signals transmitted on
either wavelength, 1550nm window is used because of lower signal loss as
pointed
above. So, provided that the link length is in 1310nm power budget, there
should
not be harm on using 1550nm other way. In short links, depending on laser
types, and overall link attenuation you might need to add attenuator on the
link to prevent the saturation in the receiver.
In case you have the goods in hand, you can try it out, but use attenuators
to emulate link if you are just connecting equipment together over short
fiber link.
Pasi
