Posts about isdn Atom feed RSS feed 2022-12-07RetroNetCall: "ISDN B-Channel protocols" 2022-11-09RetroNetCall: "OCTOI project status update" 2021-12-28OsmoDevCall: "Retronetworking: V5 interfaces in ISDN/PSTN" 2021-11-12OsmoDevCall: "E1, TDM, PDH, SDH, Basics"