Sony IPELA PCS-XG100 Operating Instructions Manual page 190

• If you want to establish an ISDN connection after connecting to six or more
other points via IP, all other connections must be severed before connecting
to the ISDN terminal.
• The bit rate will be identical for terminals connected via ISDN and via IP.
For example, if a connection with a bit rate of 2 Mbps between each IP
terminal is made and a new connection with a bit rate of 2 B (128 Kbps) is
established with an ISDN terminal, the bit rate for both the IP and ISDN
terminals will be 128 Kbps.
Note
"H.263" during ISDN connections will be supported in a future version.
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