This counter tallies the number of call setup attempts, both successful and unsuccessful, transmitted from this interface, the outbound counterpart to ciscoatmSigDetectSetupAttempts. Pairing it against ciscoatmSigOutEstabls shows how often calls this switch itself originates actually succeed, the number to watch when troubleshooting outbound call failures rather than incoming ones. This counter far outpacing ciscoatmSigOutEstabls on this interface would indicate this switch's own outgoing calls are failing at the far end or somewhere in the network, not that it's receiving too many calls.