Alpha ONUs on soak pod drop upstream ARP/ICMP packets

Soak pod is Located at RadiSys site. Runs soak tests on voltha stack every few days. The voltha stack is deployed once and every few days a test job provisions subscriber, runs tests and un-provisions subscribers. Current DT FTTH workflow is being run on this pod.

The Current issue is the alpha ONUs on this pod sends a downstream untagged packet back to RG while it should be single-tagged and this is not acceptable by RG. This issue is not seen in voltha-2.8 or voltha-2.9, but only has been observed off-late.

The Root cause Per investigation this seems to be an issue with Alpha ONUs where it strips the c-tag while it is supposed to be transparent. Alpha ONUs have exposed strange behaviors with respect to any changes in the EVTOCD configuration or any other ME configuration. Patches predating FTTB patch sets seem to work fine on this ONU but the FTTB patches per-say are not an issue. Also, the FTTB patch has passed hw sanity tests on alpha ONUs when they were merged. Also, other ONUs like Sercomm or Zyxel do not have issues.

Next Steps is to Investigate, what if any, change could have impacted the Alpha ONUs in the FTTB patch for alpha ONUs. The soak pod also has BBSIM based tests running periodically and that should continue to run smoothly.