Support of these objects is REQUIRED when the Counter32 versions can potentially wrap too frequently. This group is optional for all other hosts supporting the TN3270E-MIB. The IF-MIB (RFC 2233) requires that the 64-bit versions of its counters be implemented when an interface can support rates of around 20 million bits per second or greater. This implies a minimum wrap rate of just over 28 minutes. It is recommended that this same guideline be used for determining whether an implementation implements these objects. This group contains two objects with the syntax Counter64. An implementation that doesn't support these objects should return noSuchObject, since returning a zero is misleading.