Cable Specifications; Network Cable Specifications And Guidelines; Fiber Optic And Network Cable Specifications; Signal Loss In Multimode And Single-Mode Fiber-Optic Cable - Juniper M10i Hardware Manual

Appendix D

Cable Specifications

Network Cable Specifications and Guidelines

Fiber Optic and Network Cable Specifications

Signal Loss in Multimode and Single-Mode Fiber-Optic Cable

Network Cable Specifications and Guidelines
Cable Specifications for Routing Engine Management Interfaces
The various PICs supported on the router accept different kinds of network cable,
including multimode and single-mode fiber-optic cable. For more information, see
the following sections:
Fiber Optic and Network Cable Specifications
Signal Loss in Multimode and Single-Mode Fiber-Optic Cable
Attenuation and Dispersion in Fiber-Optic Cable
Attenuation in SONET/SDH PICs
Calculating Power Budget for Fiber-Optic Cable
Calculating Power Margin for Fiber-Optic Cable
The router supports PICs that use various kinds of network cable, including multimode
and single-mode fiber-optic cable. For information about the type of cable used by
each PIC, see the M10i Internet Router PIC Guide.
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. LEDs are not coherent sources, however. 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 cladding,
higher-order mode loss (HOL) results. Together these factors limit the transmission
distance of multimode fiber compared to single-mode fiber.
Single-mode fiber is so small in diameter that rays of light can reflect internally
through one layer only. Interfaces with single-mode optics use lasers as light sources.
on page 183
on page 183
on page 184
on page 184
on page 185
on page 185
Network Cable Specifications and Guidelines
on page 187
on page 183
183