As module bitrates elevated from 100Gbs so too did the complexity of the modules. Beginning with DSP based mostly sign conditioning and clock restoration and onwards to pluggable coherent optics, PAM-4 and CMIS. With this new stage of complexity, we needed to take a really totally different strategy to module-to-pluggable optics growth, debugging and validation. Particularly, the three key domains of module growth, debugging and validation have to be addressed:
- Excessive velocity electrical interface – excessive velocity SERDES
- Optical interface – lasers, photodiodes
- Module administration – management over I^2C interface
Traditionally, every of these areas could be debugged and validated in a considerably remoted method. The sign integrity (SI) and H/W groups would work on the high-speed electrical host interface, the photonic engineers would work on the optics whereas the S/W staff would develop and debug the module microcontroller. This strategy labored effectively as much as 100G. However with the DSP and complexity now we have now with pluggable coherent and 400G PAM-4 all these domains should be developed, debugged, and validated in a intently orchestrated matter.
On the coronary heart of that is the DSP based mostly sign conditioning and firmware. It impacts the behaviour of the photonics and host interface – from how a module responds to photonic lack of sign to how the host electrical interface is equalized– with all intimately coupled to the DSP. Because of this, a whole strategy is required to efficiently debug 400G class pluggables. Standalone I^2C debuggers and benchtop BERTs are not the precise instruments for the 400G world.
{The electrical} interface – an clever BERT which ought to help framed and unframed– should be intently coupled with module administration CMIS class instruments. In flip, they should orchestrate the photonic area occasions and impairments like OSNR and polarization scrambling.
VIAVI has been at the vanguard of pluggable optics take a look at and measurement for greater than a decade and our ONT 800G and MAP product strains supply built-in, multi-domain module T&M instruments prepared for 400G and above. Our TraCol utility brings msec module administration and management decision, coupled with full host electrical interface and utility orchestration. It may additionally help shut coupling of photonic impairments to present full management and visibility in all domains.
Backside line: Don’t attempt to debug complicated DSP-based modules with last-generation fundamental instruments, counting bit errors is of no assist at past 100G. Use the ONT built-in strategy with perception and smart purposes and grow to be at one together with your module. That is the true path to Zen!
To start out by yourself path to Nirvana, contact a VIAVI consultant as we speak.
