HP StorageWorks SAN Director Installation Guide (A7393-90009, May 2007)

SAN Director installation guide 177
8 Setting up and installing modems
This chapter provides the following information:
• Using high availability connectivity, page 177
• Connecting modems, page 179
• Setting up a remote modem system, page 180
• Verifying the modem connection, page 181
Each CP card in the 4/256 SAN Director contains a modem serial port for connection to a
Hayes-compatible modem. The modem serial ports are wired as standard DTE ports and have the
same commands, log in capabilities, and operational behavior as the terminal serial ports.
However, asynchronous informational messages and other unsolicited text are not sent to the modem
ports. No additional software is required to use modems with the 4/256 SAN Director.
NOTE: The 4/256 SAN Director detects modems only during power-on, reboot, or a CP card
failover sequence. Setting up the modems before powering on the 4/256 SAN Director is
recommended.
For increased security, any active modem sessions are automatically disconnected if the modem
cable is disconnected.
For optimal security, disconnect the modem cable when it is not in use.
Using high availability connectivity
High availability of the modem connection can be ensured by connecting a separate modem to
each CP card and then connecting both modems to a shared telephone line (see Figure 39). This
ensures an available telephone connection to the active CP card even if a failover occurs; however,
it is necessary to log back in after a failover. When both CP cards are connected to a shared
telephone line, callers are automatically dialed in to the active CP card, which answers on the first
ring. If the active CP card cannot answer for any reason, the standby CP card answers on the
seventh ring and allows login to proceed.