Cisco Hoot and Holler over IP Configuration Examples
21
Cisco IOS Release 12.1(5)T
Dial peers are identified by numbers, but to avoid confusing these numbers with telephone numbers,
they are usually referred to as tags. Dial peer tags are integers that can range from 1 to 231 -1
(2147483647). Dial peers on the same router must have unique tags, but you can reuse the tags on other
routers.
The following commands show how to configure a dial peer with tag 1 for this voice port:
!Configure dial peer.
!Conference 1.
!Phone number 111.
!Multicast address 237.111.0.0, udp port 22222.
dial-peer voice 1 voip
destination-pattern 111
session protocol multicast
session target ipv4:237.111.0.0:22222
ip precedence 5
codec g711ulaw
!
Note The configuration for the codec g711ulaw in the above configuration is not
necessary—the default codec of g729r8 could be used (and it would not display for show
config).
Tips • The destination-pattern 111 for the VoIP dial peer matches the connection trunk
string for the corresponding voice port.
•The session protocol multicast command is essential for voice multicasting.
•The session target for voice multicasting dial peers is a multicast address in the range 224.0.1.0 to
239.255.255.255. This session target must be the same for all routers in a session. The audio RTP
port is an even number in the range 16384 to 32767, and must also be the same for all routers in a
session. An odd-numbered port (UDP port number + 1) is used for the RTCP traffic for that session.
•The following codec restrictions apply:
–
You must configure the same codec on all dial peers and routers in a session.
–
Only G.711, G.726, and G.729 codecs are supported.
–
When the default codec, G.729r8, is used, it does not appear in the configuration.
•Voice activity detection (VAD) is enabled by default. Cisco recommends that this setting should not
be changed.
Ethernet Configuration
Configure the router’s Ethernet interface as follows:
!Configure physical interface for transmitting multicast packets.
!
interface ethernet 0/0
ip address 1.5.13.13 255.255.255.0
ip pim sparse-dense-mode!