A read-only counter of errors that occurred when the convergence port attempted to establish a connection with a WAN service. The description notes this may indicate congestion at the WAN service or a configuration problem, so an admin uses a rising count as a trigger to check both possibilities rather than assuming just one. If cxFwkStatsOpenErrors spikes right after a WAN provider reports a network-wide issue, the admin would attribute the errors to provider-side congestion rather than a local misconfiguration.