In 1992, Cisco earned its first patent, number 5,088,032, for Interior Gateway Routing Protocol (IGRP), a method for routing between computer networks. IGRP is a proprietary routing protocol developed by Cisco to overcome the limitations of the standards-based protocol, RIP. The 15-hop count limit of RIP was a significant limitation in large networks. IGRP uses a number of metrics, including bandwidth, delay, hop count, and reliability, to determine best route. IGRP evolved into EIGRP and was a significant upgrade for most organizations, performing significantly faster and scaling much better than RIP. IGRP was the first of many proprietary protocols that improved on the standard (EtherChannel, Skinny, etc.).