"16*E1s 2U chassis, SIP, PRI/SS7 G.711A/U,G.723.1,G.729A/B, iLBC,AMR SDH STM-1 155M interface 1+1 Redundant power supplies" "32*E1s 2U chassis, SIP, PRI/SS7 G.711A/U,G.723.1,G.729A/B, iLBC,AMR SDH STM-1 155M interface 1+1 Redundant power supplies" "48*E1s 2U chassis, SIP, PRI/SS7 G.711A/U,G.723.1,G.729A/B, iLBC,AMR SDH STM-1 155M interface 1+1 Redundant power supplies" "63*E1s 2U chassis, SIP, PRI/SS7 G.711A/U,G.723.1,G.729A/B, iLBC,AMR SDH STM-1 155M interface (63*E1) up to 1890 concurrent calls 1+1 Redundant power supplies"