While Futhey notes that Duke is still trying to "fully characterize" the problem before releasing more information, he claims there is nothing specific about the iPhone that is responsible. Initial reports indicated that the iPhone's Wi-Fi roaming feature was to blame, since it would repeatedly hunt for the MAC addresses of invalid router addresses as it attempted to switch from one hotspot to another. This supposedly flooded Duke's network, and the university originally denied that Cisco had any responsibility for the outages. Both Apple and Cisco are said to be long-term corporate partners with Duke.