While evaluating high-speed network test equipment, it may be tempting to forgo deep physical layer testing capabilities to save money and reduce testing complexities. In some cases, these ‘just good enough’ solutions appear to fit the bill, but lack of deep insights can lead to product re-designs, longer development cycles or systemic failures in the […]
Since the emergence of 400 Gigabit Ethernet (GbE) around 5 years ago, we have seen PAM-4 modulation replace NRZ on both optical and electrical interfaces. We now see a broad and healthy ecosystem building for 400 GbE, and even 800 GbE, using PAM-4 signaling. In fact, we are even seeing the first 100 Gb per […]
If you would like a more in-depth review of what the path forward with 800G pluggable optics may look like may we suggest watching Preparing the Way for 800G: 100G Electrical and 800G Pluggable Optics. —————————————————————————————————————————————————————————————– The creation of the 800G ecosystem has begun. Alpha samples of 800G OSFP modules have been demonstrated and we […]
One of the great challenges facing data communications is matching the silicon bandwidth with the face plate density. Today, switch silicon can process over 12 Tb/s. But getting this off the front panel at a reasonable density is a challenge. One direction is to move to faster Ethernet speeds. A great example of this is […]
The ability to generate errors is a basic feature in most test sets, it can be used to establish if the receiver can detect and signal if errors occur. Of course, the VIAVI ONT has taken this to new levels with our advanced FEC stress tools used to validated and troubleshoot FEC correction logic and […]
One of the questions we get asked now and then is on the connector life in our ONT products. Pluggable optical modules can be plugged in and out of our test sets, both as part of their test and validation but also in normal applications engineers will plug in and out different optical interfaces in […]
With the move to pluggable coherent optical modules for the first time since 10G, we see client and line side considerations coming together. The most obvious example of this is optical signal to noise (OSNR) and related measurements. For any modules with the potential for use in an amplified system, OSNR becomes the fundamental figure […]
With the advent of 400G Ethernet, it has become critically important to fully understand and validate Forward Error Correction (FEC) logic and the related software and firmware. 400G Ethernet uses PAM-4 signalling optically and electrically. Because of the susceptibility to the impact of noise, distortion, and other disturbances, most links will run with a raw error […]
Growing up in Castleisland, County Kerry, my family was lucky to know the famous journalist Con Houlihan. With his fantastic command of the written word he was often asked to advise on the progress of young student’s written English by concerned mothers. Con’s stock reply would normally be ‘Well, they are making all the right […]
Optical interconnectivity at 400 Gbps has introduced many new design challenges. These include the step from NRZ to PAM-4 coding with the presence of a background error rate, the new QSFP-DD form factor for transponders with thermal and integration challenges and aggressive cost expectations early in the lifecycle. One of the most difficult challenges is […]
