The unidirectional transmission links such as broadcast satellite links and cable links are strongly demanding type of link to provide high bandwidth and ubiquitous Internet connectivity with lower cost. In order to provide an internet connectivity, the UDLs, unidirectional links, should be available for the IP service. However, since the current Internet routing and upper layer protocols assume the bi-directional link, the UDLs have been considered as unavailable links for the IP service. This paper proposes an architecture and a mechanism for the IP service over the UDL. The proposed system emulates the bi-directional connectivity between all nodes on the UDL, in order to use the dynamic routing protocol, the TCP/IP protocol, on the UDL system. Receiver uses a link layer tunneling mechanism to forward the IP datagrams to the Feed over an IP cloud, that is not directly connected to the UDL. This proposed architecture enables the dynamic routing capability for UDLs, as well as user applications, without any software modification.