As in all engineering, this involves tradeoffs - the network must have adequate performance, be sufficiently reliable, but should not use more resources than required.
æz ɪn ˈɔːl ˌɛndʒɪnˈɪɹɪŋ, ðɪs ɪnvˈɑːlvz tɹˈeɪdɔfs ðə nˈɛtwɜːk mˈʌstɐv ˈædɪkwət pɚfˈoːɹməns, biː səfˈɪʃəntli ɹᵻlˈaɪəbəl, bˌʌt ʃˌʊd nˌɑːt jˈuːz mˈoːɹ ɹᵻsˈoːɹsᵻz ðɐn ɹᵻkwˈaɪɚd.