This document proposes a limited set of Diffserv PHBs and codepoints to be applied at (inter)connections of two separately administered and operated networks. Many network providers operate MPLS using Treatment Aggregates for traffic marked with different Diffserv PHBs, and use MPLS for interconnection with other networks. This document offers a simple interconnection approach that may simplify operation of Diffserv for network interconnection among providers that use MPLS and apply the Short-Pipe tunnel mode.