Testing is Essential for 400G Third-Party Optics
It is unsure to many when it will exactly happen, but 400G connectivity is the next big thing in networking. Many have already started preparing for this transition, with millions of 400Gbps switches already being shipped out over the past couple of years. Soon, more and more will be populated in 2020. The major switch from 100G to 400G represents a much-needed increase in bandwidth. From streaming 4K video to hyperscale data centers, speed has become a necessity for most. Yet, 400G has presented some challenges for those looking to migrate due to its complex infrastructure.
A major requirement for successful and error free implementation of 400G is simply testing. This is an issue that separates quality and functionality when customers choose among third party transceivers. AddOn Networks has developed a precise system in which 400G modules go through that ensures full functionality at its state-of-the-art testing lab.
It is said that transceivers below 100G use a simpler modulation scheme. In fact, PAM4, the scheme that is chosen for many 400G networking systems is even more complex as it has two bits into a single symbol with four amplitude levels. PAM4 provides the given data rate at half the frequency, meaning it doubles the network throughout while also reducing power consumption.
PAM4 creates some challenges though, even with all these upsides. The signal-to-noise ratio (SNR) effectively reduces transceiver reach. To mitigate the loss of signal integrity, in 400G there is a greater need for forward error correction (FEC). This is why module testing is so essentially and third party suppliers that are not able to test precisely will risk losing customers by providing low quality products
AddOn Networks' in-house testing facility is committed to quality as 400G testing has come full circle. This ensures quick delivery to customers and is the root cause of why customers choose third-party transceiver sources in the first place.
400G testing can be complicated; it is unlike the earlier generations of transceiver technology. It focuses more on if reliability levels are acceptable, rather than whether there are actual errors. Post-FEC, some 400G transceivers will operate error free while others will not. There seems to be a more sophisticated understanding of the error distribution method and what the root causes are that make these errors occur. FEC is complex and needs testing for logistical and dynamic power performance errors as well.
400G Testing at AddOn
The AddOn lab includes a MultiLane BERT tester, which is essential to testing the 400G factors above. There are also ways to provide information on how well a 400G transceiver behaves across networks. Whether it be in a Cisco, Juniper, or Arista these 400G switches can be tried out. There is also a EXFO 400G traffic generator that can be used to simulate how well traffic conditions are, or how 400G transceivers will perform on a specific network. If a customer buys from a supplier that does not have its own testing lab and equipment, the risks involved will be great and could extend lead times. The change from 100G to 400G is a necessity as we push network connectivity forward.