A Virtual Leased Line (VLL) service is a point-to-point data communication using ADSL network (over ATM) for communicating any data between two sites. The data speed of VLL depends on customer requirements such as 64, 128, 256, 512 Kbps.In actual network, multiple users are connected to DSLAM ; furthermore, the service provider assigns the VLL ratio for bandwidth sharing, when each customer sends data simultaneously. This is a disadvantage of VLL service when compared with Leased line (LL) service. The benefit of a VLL service is that