ery high frame efficiency SO achieved. In addition to sizing the transport paths to handle the peak bandwidth expected, VCAT may be used to create an arbitrary-sized transport pipe. The pipe may be sized for the average bandwidth consumed for a single connection, or may be sized in order to provide a statistically multiplexed transport pipe. 3.3.2.3 Dynamic Bandwidth Allocation Along with VCAT, the capability to dynamically change the amount a bandwidth used for virtual concatenated channel has been developed. This capability is commonly referred to as Link Capacity Adjustment Scheme (LCAS). Signaling messages are exchanged within the SONET overhead in order to change the number of tributaries being used by Telecommunication Networks TABLE 3.4 Efficiency of VCAT in Mapping Ethernet Signals Frame Ethernet Rate VCAT Channel SONET Rate Efficiency (%) 10Mbit/s Ethernet VT-1.5-7v ~11.2Mbit/s 10Mbit/s Ethernet VT-2.0-5v ~10.88Mbit/s 100 Mbit/s Fast Ethernet STS-12v ~96.77Mbit/s Gbit/s Ethernet STS-1 21v ~1.02 Gbit/s Gbit/s Ethernet STS-3c-7v ~1.05 Gbit/s a Virtually Concatenated Group (VCG). The number of tributaries may be either reduced or increased, and the resulting bandwidth change may be applied without loss of data in the absence of network errors. The ability to change the amount of bandwidth allows for further engineering of the data network and providing new services. Bandwidth can be adjusted based on time-of-day demands and seasonal fluctuations. For example, businesses can subscribe to higher bandwidth connections (for backup, etc.) when the demand for bandwidth is low and hence the cost is lower. LCAS can further provide "tuning" of the allocated bandwidth. If the initial bandwidth allocation is only for the average amount of traffic rather than the full peak bandwidth, and the average band- width usage changes over time, the allocation can be modified to reflect this change. This tunability can then be used to provide (and charge for) only as much bandwidth as the customer requires. 3.3.3 IP over MPLS ov