This Recommendation gives the characteristics of equipment (external to PCM muldexes) operating at 2048 kbit/s and providing one or several of the following tributaries into/from channel time slots of a 2048 kbit/s composite signal: bidirectional synchronous 64 kbit/s access (Figure l a/G.739); unidirectional synchronous 320 kbit/s access (Figure 1b/G.739).