Can a server K56flex modem call another K56flex server?
No, only client and server K56flex modems can interact. (Both Rockwell and Lucent are debating the possibility of K56flex to K56flex calls.) Client-client and server-server connections will use V.34 modulation speeds. See the section “%Ln (Speed Matching)” in the AT Command Set and Register Summary for V.34 and 56K 12-Port Modules publication for details. Note that if the line is PRI, the servers can call each other using ISDN at 65 Kbps.