CableLabs’ XGS-PON Interop·Labs series has grown with every round this year, and October’s event — our third and final one of the year — brought together the largest group of suppliers yet. The event again focused on the ONU Management and Control Interface (OMCI), defined in ITU-T Recommendation G.988 and the Cable OpenOMCI I04 specification. That momentum carries straight into 2027: the Cable OpenOMCI I05 specification is now published, and our next PON interop, scheduled for February, will put it to the test.
In the latest interop, held Oct. 19–22, we again paired optical line terminal (OLT) and optical network unit (ONU) equipment from different suppliers to validate service configuration and monitoring scenarios. Suppliers brought updated software builds and new ONU models. The set of suppliers grew to include five OLT suppliers and 10 ONU suppliers, many of which brought multiple device models to the event.
XGS-PON, a passive optical network (PON) technology standardized by the ITU-T, supports symmetrical 10 Gbps speeds over fiber. OMCI is the protocol an OLT uses to configure, monitor and troubleshoot the ONUs connected to it.
Supplier Participation in the XGS-PON Interop
Thank you to the suppliers who participated in the October event. Their equipment spanned multiple device architectures and chipset families.
The OLT platforms were Adtran’s SDX 6312-4, Calix’s E7-2, Ciena’s uOLT (represented by RocNet), Nokia’s Lightspan MF-2 and Vecima’s EXS1610. These OLT systems were paired with layer-2 bridge ONUs and ONUs embedded in residential gateways from Adtran, Calix, Gemtek, Hitron, Nokia, RocNet, Sagemcom, Tinno, TP-Link and Ubee.
All told, we tested 50 OLT-to-ONU pairings during the interop week, up from 34 in June.
Testing Environment and Themes
As in earlier events, we created a dedicated network for each OLT system within our isolated Interop·Labs network. Each OLT system supported a local PON optical distribution network linked to one or more ONUs under test. Engineers used OLT debugging tools and a CableLabs-provided XGS-PON analyzer to capture OMCI message exchanges and traffic behavior in each scenario.
Nearly all OLT-to-ONU pairings successfully handled the following test areas:
- ONU registration and MIB upload
- Core managed entities (MEs), including ONU-G, ONU data, software image, cardholder, circuit pack, T-CONT, ANI-G and Priority queue
- Service provisioning MEs, including GEM interworking termination point, GEM port CTP, interworking point, GAL Ethernet profile, MAC bridge port configuration data, MAC bridge port filter pre-assign table, IEEE 802.1p mapper service profile, Extended VLAN tagging operation configuration data (downstream mode 6) and OLT-G
- ANI-G optical power reporting, including Rx power, mean launch power, laser bias current and temperature
- Ethernet link-loss alarms and traffic forwarding recovery after the link returns
In plain terms, these test areas covered bringing an ONU online, identifying its hardware and software, provisioning data services, monitoring optical signal health and recovering from link failures.
Many of the participating suppliers showed improvement in problem areas noted at earlier events. Broad test plan coverage of the Cable OpenOMCI requirements surfaced additional items, which will guide further OLT and ONU software development work toward conformance.
PON Interop Plans for 2027
As we plan for the new year, we’ll continue the cycle of lab validation, specification updates and new OLT and ONU software builds, with each round aiming to improve cross-vendor interoperability. Our next PON interop, in February 2027, will exercise the Cable OpenOMCI I05 specification. We look forward to seeing suppliers back in our Louisville, Colorado, labs and continuing to build on this momentum.
