Sony PCS-1/1P Operating Instructions Manual page 211

Message
Use of the Private Phone Book is
not available.
The system is connecting to a
LAN via PPPoE.
Meaning
The "Memory Stick" in which the Private Phone Book is
registered has been removed from the Communication
Terminal. You cannot use the Private Phone Book.
The Video Communication System is connecting to a LAN
using PPPoE.
On Screen Messages
211