In Unspecified Bit Rate (UBR) service provided by ATM networks, users send cells into networks with no feedback, no guarantee cells may be dropped during congestion. This paper describes a congestion control scheme using active network technology to avoid congestion in a conventional ATM network. Ants routing algorithm for congestion control and associated with active network fashion is implemented.

The routing algorithm uses information that is monitored and revised according to the congestion status of output ports and sends commands to other switching elements. The Active switching elements share information about traffic levels of an interconnection network and reciprocate customized programs to rerouting cells in the presence of congestion at switching element's output ports. As a result, it is possible to build active switching network that can avoid congestion in a conventional ATM network.