On the Scalability of Open RAN's SMO Heartbeat Management with O-RAN SC

The Open RAN specification breaks vendors' lock-in promoting software defined networking principles, which establish the centralization of some network functions, particularly, the failure management (a.k.a., Heartbeat Service). However, centralization may introduce performance bottlenecks. Thus, this paper evaluates the scalability of the Heartbeat Service implemented by the O-RAN Software Community. Through measurements, we analyse how this service behaves when the infrastructure grows. Our results show the service reaches an average capacity about 45 messages/s. Moreover, we verified that the message sending period caused the biggest impact on performance, showing that operators must carefully configure this parameter to avoid false failure detection.