The Cisco IP Communications voice/fax network modules for the Cisco 2800, 2900, 3800, and 3900 Series unified communications routers enable packet voice technologies including VoIP (H.323, Media Gateway Control Protocol [MGCP], and Session Initiation Protocol [SIP]). Cisco Unified Communications solutions provide the means for integrating voice and data within a single network, allowing users to take advantage of services such as IP telephony, integrated services, and toll-bypass while providing an opportunity to improve productivity. By operating on Cisco IOS Software, these solutions incorporate advanced quality-of-service (QoS) features, intelligent network queuing, and standards-based encapsulation, providing efficient direct transport of both voice and fax over IP networks. Cisco IOS Software solutions enable time-sensitive voice traffic to be moved across even low-bandwidth WAN connections with the priority and quality that voice and fax demand. Transporting voice over IP networks continues to provide transport flexibility because IP can be routed across a multitude of WAN technologies (leased lines, Frame Relay, and ATM) along with providing direct connectivity to the desktop.