Configure The Rtp Parameters - Cisco 8851 Administration Manual

Procedure
Step 1 On the phone web page, select Admin Login > Advanced > Voice > Systems.
Step 2 In the Optional Network Configuration section, enter IPv4 or IPv6 address in the Primary NTP Server
and Secondary NTP Server .
Step 3 Click Submit All Changes.

Configure the RTP Parameters

Procedure
Step 1 In the phone web user interface, navigate to Admin Login > advanced > Voice > SIP.
Step 2 In the RTP Parameters section, set the Real-Time Transport Protocol (RTP) parameter values as described
in RTP Parameters, on page
Step 3 Click Submit All Changes.
Control SIP and RTP Behaviour in Dual Mode
You can control SIP and RTP parameters with SIP IP Preference and SDP IP Preference fields when phone
is in dual mode.
SIP IP Preference parameter defines which IP address phone tries first when it is in dual mode.
Table 12: SIP IP Preference and IP Mode
IP Mode
Dual Mode
Dual Mode
226.
SIP IP Preference Address List from DNS,
Priority, Result
P1 - First Priority Address
P2 - Second Priority
Address
IPv4 P1- 1.1.1.1, 2009:1:1:1::1
P2 - 2.2.2.2, 2009:2:2:2::2
Result: Phone will send
the SIP messages to
1.1.1.1 first.
IPv6 P1- 1.1.1.1, 2009:1:1:1::1
P2 - 2.2.2.2, 2009:2:2:2::2
Result: Phone will send
the SIP messages to
2009:1:1:1::1 first.
Cisco IP Phone 8800 Series Multiplatform Phones Administration Guide
SIP and NAT Configuration
Failover Sequence
1.1.1.1 ->2009:1:1:1:1 ->
2.2.2.2 -> 2009:2:2:2:2
2009:1:1:1:1 ->
1.1.1.1 -> 2009:2:2:2:2 ->
2.2.2.2
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