The KPUD network new XGSpon systems

We are happy to report that the technical issues with the Calix XGSpon infrastructure have been resolved. The vendor (Calix) provided a firmware update for their equipment which corrected a “Training” error on the fiber links.

We have no widespread issues, or even pockets of problems on the XGSpon infrastructure anymore.

In the spring of 2024 KPUD started deploying a new technology for them called XGSPON. This service uses fiber optic “splitters” in the field to take one upstream (towards their equipment) connection and divide it into multiple downstream connections (towards your home).

This is very mature technology. This is what Google fiber, Centurylink, Comcast, Cox, Time Warner use. This is what Net253 uses for some of our own network operations.

XGSpon is pretty amazing; it supports 10,000mbit download and 10,000mbit upload. This insane speed is then multiplexed between the number of homes that are “split” to. The technology supports (and the big ISPs use) 1:128 split ratios. So 32 to 128 homes share 10,000mbit of download/upload speed. The usage is dynamically split; when a home is using less data, the bandwidth is not wasted on them but made available to the others. KPUD settled on a conservative 1:32 ratio for splitting. This split is higher quality than their legacy, where up to 48 homes share a 10,000mbit feed.

The beauty of XGSpon is the 1:32 splitter uses no power and can be deployed in the field near a cluster of homes. This eliminates a very large, expensive, power hungry networking switch and 33 fiber optic modules that plug into said switch. By multiplexing near the homes, instead of 32 fibers back to the cabinet, there is only one for most of the run. When a fiber is cut, getting all the homes back online is now 32 times faster than previously. This translates to better reliability (ignoring our current situation), lower operating cost, lower initial cost, and higher density in their cabinets.

As the fall came around we started having folks complain about frequent intermittent buffering/outages. We are not experiencing complaints from folks on the older legacy “active ethernet” systems KPUD operates. These legacy connections use a dedicated strand of fiber for every home and have two fiber modules per home, one per end of the link. The link operates at “just” 1,250mbit.

We are working with KPUD to identify possible solutions. KPUD is feverishly working to correct the situation. With the new technology, once KPUD has a solution, we can create a list of every impacted home in the county. Once fixed, the service is totally stable. If you are having issues, please let us know and we will put your address in the “churn”.

This issue is what is lingering in the Moutainaire area that was impacted by the fiber cut we blogged about.

Even though we have these “teething” issues with KPUD at the moment, XGSpon is the future. We would be happy if they upgraded their entire network to XGSpon. But that is cost prohibitive at the current time.