Nokia sees limits on how far IP and optical network convergence can go

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Nokia's Steve Vogelsang argued “to support a long-haul network, you really need more power." (Nokia)

Cisco recently pitched the proliferation of ZR and ZR+ pluggables as a technological tipping point which will enable operators to merge the IP and optical elements of the network into a single layer. But Nokia’s message on the subject is a bit more nuanced, boiling down to the saying “one size doesn’t fit all.”

Steve Vogelsang, CTO for Nokia's IP and Optical Networks Business, told Fierce merging the two layers does make sense and can yield efficiencies in certain circumstances. He pointed to metro networks as a prime candidate for the aforementioned single-layer architecture, adding packet collector rings and high-traffic routes between two routers are the two most common use cases “resonating” with customers thus far.

But he noted “the thing to keep in mind is these 400 ZR, ZR+ pluggables…you’re distance limited.” Vogelsang explained the reach of 400G ZR pluggables maxes out at around 120 kilometers, while ZR+ pluggable transmissions can generally go around 500 kilometers. (It should be noted, though, that Windstream Wholesale and Cisco’s Acacia recently hit a record 1,027 kilometers during a 400G ZR+ pluggable trial in February.)

RELATED: Cisco highlights how ZR pluggables are changing optical architecture

“We kind of look at that and say well it’s going to lead to all sorts of complexities in the IP layer because what ends up happening is if you can’t get the reach you need you have to drop more and more routers in place,” he said.

Vogelsang argued “to support a long-haul network, you really need more power. You have to enable a bunch of features in the DSP [digital signal processor] that, one, typically don’t exist in the smaller, low-power DSPs that would be integrated into a pluggable.”

Though new generations of DSPs which are smaller and lower-power could potentially enable operators to address more use cases with optics integrated in a router, Vogelsang said “I think for the foreseeable future there will be these two different distinct technologies, one targeting the long haul, one targeting sort of metro/regional.”

Business focus

Vogelsang also addressed investment priorities for Nokia’s IP and optical businesses, which are now part of the company’s new IP and Fixed Networks group following a restructuring which took effect at the start of 2021.

As far as optical is concerned, he said there’s a big focus on DSP technology, while the IP business is continuing to invest in broadening its silicon portfolio.

He stated its IP business has “been gaining market share for quite some number of years…Depending on the region, either number one, number two typically as a routing vendor.” Its optical operation is “also a very strong business for us” and “again depending on the region typically would be probably around number two because Huawei shows up in more areas in the optical business.”