... with E1, FXO/FXS access port; 2)4~100 E1, 192 FXO/FXS; 3)Support SS7, PRI, R2, V5.2 signaling ... , E1 can be expanded with plug in moudule.· Maxima support 192 FXS ( can be replace by FXO by different moduleParts information ... :Application as follow shows: Digital PBX \ PBX Telecom System with 192 ports FXO/FXS