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Life Begins at 40(km) - 100G ZR Optics
Jun 27, 2015

The adoption of 100G has been underway for a long time. If you have a good memory, you'll recall that Juniper released the world's first 100GE router interface way back in 2009. Since that time, we've seen wide deployment of 100G Ethernet interfaces in many flavors and form-factors. That first interface back in '09 could go up to 10km using 100GBASE-LR4 optics. Not long afterwards 40km was possible with 100GBASE-ER4. Shorter reach, lower-cost options also came along. With the modular nature of pluggable optics, it has been pretty easy to pick the optimal module type for each interface and target link. 
 
Beyond 40km
While 100G is becoming near-ubiquitous, moving beyond 40km has proven to be a real challenge for client interfaces. Unlike LR4 and ER4, IEEE 802.3 doesn't define a standardized way to go beyond 40km, yet many networks need links up to 80km. At 10G rates, the industry developed a de-facto standard called 10GBASE-ZR for this specific application. However, network operators wishing to upgrade their 80km links to 100G have faced a real dilemma. To put it bluntly, it's a really tough problem to solve, especially when limited by the power & size available to conventional grey optics.
 
Introducing CFP-100GBASE-ZR
To address these needs, Juniper has announced the availability of its CFP-100GBASE-ZR module. This new pluggable optical interface module packs an impressive array of technology into a compact CFP. The CFP-100GBASE-ZR module uses DP-QPSK modulation and coherent receiver technology with an optimized DSP and FEC implementation. All of this is packed into a low-power module that can be directly retrofitted into existing CFP sockets on MX and PTX routers already deployed in the field - no new line cards or PIC/MICs are needed. 
 
CFP-DCO.png
New CFP-100GBASE-ZR Module for MX & PTX
 
Coherent Advantages
When it comes to optical performance, maximum reach and link robustness coherent technology is second to none. For this reason, all the big boys use coherent interfaces for metro and long haul link at 100G and beyond. Why is this a big deal? Consider the advantages:
  • Adaptive Impairment Compensation - Chromatic dispersion (CD), polarization mode dispersion (PMD) and polarization rotation are all dynamically compensated using DSP logic
  • Increased Optical Sensitivity - A coherent receiver and local oscillator provide high sensitivity making signal recovery possible after long distances
  • Forward Error Correction - Integrated FEC detects and corrects for received bit errors at the physical layer without L3 re-transmission
The Time is Right
While optical coherent interfaces are not new (Juniper has been shipping long haul coherent interfaces on PTX since 2013), squeezing all of that technology into a pluggable, low-power module is a breakthrough. Not only can you reuse your existing hardware, but earlier Junos releases (back to 13.3) are also supported. Of course, please read the fine print for your platform (PTX, MX MPC3, MX MPC4) for more details.
 
With the inherent performance and robustness of coherent optics and backwards hardware & software compatibility, CFP-100GBASE-ZR is a plug & play solution to bring 80km 100G to your MX & PTX-based networks. Finaly, there really is life after 40km.