Other methods of determining link speed like CDP or LLDP

We've noticed that OmniCenter is sometimes unable to gather correct link speed from our network devices. This seems like it could be avoidable because the opensource tool Netdisco discovers the speeds correctly. There may be other methods available to determine link speed, like the Cisco Discovery Protocol, or LLDP, that may be valuable to customers like us that cannot possibly manually configure the link speed for every port on every device in order to get thresholds set correctly.