A subnetwork which supports an arbitrary number of end systems and intermediate systems, but does not support a convenient multidestination connectionless transmission facility, as does a broadcast subnetwork.; 一種類型的子網(wǎng),支持任意數(shù)目的端系統(tǒng)和中介系統(tǒng),但不支持如廣播子網(wǎng)那樣的方便 的多終點(diǎn)無連接傳輸設(shè)施。