This Recommendation describes aspects which are pertinent to and should be considered in the design of international Signalling System No.7 (SS No.7) signalling networks. Some or all of these aspects may also be relevant to the design of national networks. Some aspects are dealt with for both international and national networks (e.g. availability), others are discussed in the context of the international network only (e.g.the number of signalling transfer points in a signalling relation). A number of aspects require furiher study for national networks. This Recommendation also gives in Annex A examples of how the signalling network procedures may be applied to the mesh network representation.