We consider in this paper a network that consists of two senders and two receivers. We further assume that each sender could act as a relay for other communications. All channels connecting these nodes are supposed to be erasure channels where symbols are received correctly (error-free), or lost. This model is realistic for many practical scenarios in the context of wireless and sensor networks. In a previous works, we have addressed the capacity region of this network under physically degraded hypothesis. The non-degraded case is addressed in this paper. We derive a capacity bound for the proposed network and we show that it can be reached through a practical coding scheme based on MDS codes. We make also a comparison of the achieved rates compared to a simple time sharing of single sender relay channels.