Overview Of Ex Series Switches: Fiber-Optic Cable Signal Loss, Attenuation, And Dispersion - Juniper EX9214 Hardware Manual

optical modules or cables. Your JTAC engineer will likely request that you check the
third-party optical module or cable and, if required, replace it with an equivalent
Juniper-qualified component.
Use of third-party optical modules with high-power consumption (for example,
coherent ZR or ZR+) can potentially cause thermal damage to or reduce the lifespan of
the host equipment. Any damage to the host equipment due to the use of third-party
optical modules or cables is the users' responsibility. Juniper Networks will accept no
liability for any damage caused due to such use.
The Gigabit Ethernet SFP, SFP+, and QSFP+ transceivers and the 100GBASE-LR4 CFP transceivers
installed in EX9200 switches support digital optical monitoring (DOM): You can view the diagnostic
details for these transceivers by issuing the operational mode CLI command
.
optics
Overview of EX Series Switches: Fiber-Optic Cable Signal Loss,
Attenuation, and Dispersion
IN THIS SECTION
Signal Loss in Multimode and Single-Mode Fiber-Optic Cable | 138
Attenuation and Dispersion in Fiber-Optic Cable | 139
To determine the power budget and power margin needed for fiber-optic connections, you need to
understand how signal loss, attenuation, and dispersion affect transmission. EX Series switches use
various types of network cables, including multimode and single-mode fiber-optic cable.
Signal Loss in Multimode and Single-Mode Fiber-Optic Cable
Multimode fiber is large enough in diameter to allow rays of light to reflect internally (bounce off the
walls of the fiber). Interfaces with multimode optics typically use LEDs as light sources. However, LEDs
are not coherent light sources. They spray varying wavelengths of light into the multimode fiber, which
reflects the light at different angles. Light rays travel in jagged lines through a multimode fiber, causing
signal dispersion. When light traveling in the fiber core radiates into the fiber), higher-order mode loss
(HOL) occurs. (Cladding consists of layers of lower-refractive index material in close contact with a core
show interfaces diagnostics
138