private bool IsExpiresValid(SipMessageReader reader) { int expires = reader.GetExpires(defaultExpires, maxExpires); for (int i = 0; i < reader.Count.ContactCount; i++) { int localExpires = reader.Contact[i].Expires; if (localExpires == int.MinValue) { localExpires = expires; } if (localExpires != int.MinValue && localExpires > 0 && localExpires < minExpires) { return(false); } } return(true); }