The Cisco 801 through the Cisco 804 Series supports ISDN switched, leased line connections, Always on Dynamic ISDN (AODI), X.25 over ISDN D channel, Bandwidth Allocation Control Protocol (BACP), Multilink Point-to-Point Protocol (ML-PPP), Compression Control Protocol (CCP) compression (up to 4:1), and Bandwidth on Demand (BOD) with load balancing for links up to 128kbps, for effective throughput up to 512kbps.