The Ethernet over E1 approach,which takes advantage of widely deployed telecom networks,is an efficient and economical way to interconnect two Ethernets in different regions.Two Ethernet over E1 schemes, namely a byte granularity scheme and a frame granularity scheme are discussed. The byte granularity scheme partitions Ethernet frames into several pieces for transmission and has a strict requirement on the maximum delay difference of multiple E1 links. To solve this problem, the newly proposed frame granularity scheme transmits separately each frame through E1 links without any partitioning. The architecture designs of both schemes are presented. This paper evaluates the throughput and delay performances of both schemes, both analytically from results calculated from delay models and using test results from field programmable gate array (FPGA) implementation. Although the frame granularity scheme has a slightly worse delay performance, it has a higher throughput, and is the only choice able to overcome large delay differences of the E1 links.