Specifications

Setting Up Cisco Unified IP Phones
How to Set Up Cisco Unified IP Phones
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Cisco Unified Survivable Remote Site Telephony Version 4.0 System Administrator Guide
Configuring Dual-Line Phones
Dual-line phone configuration is required for dual-line phone operation during Cisco Unified
CallManager fallback. Consultative transfer is also required (see the “Enabling Consultative Call
Transfer and Forward Using H.450.2 and H.450.3 with Cisco SRST 3.0” section on page 82).
Dual-line IP phones are supported during Cisco Unified CallManager fallback using the max-dn
command. Dual-line IP phones have one voice port with two channels to handle two independent calls.
This capability enables call waiting, call transfer, and conference functions on a phone-line button.
In dual-line mode, each IP phone and its associated line button can support one or two calls. Selection
of one of two calls on the same line is made using the blue Navigation button located below the phone
display. When one of the dual-line channels is used on a specific phone, other phones that share the
ephone-dn will be unable to use the secondary channel. The secondary channel will be reserved for use
with the primary dual-line channel.
It is recommended that hunting be disabled to the second channel. For more information, see the
“Configuring Dial-Peer and Channel Hunting” section on page 78.
SUMMARY STEPS
1. call-manager-fallback
2. max-dn max-directory-numbers [dual-line] [preference preference-order]
3. exit