
Cisco Hoot and Holler over IP
Configuration Examples
18
Cisco IOS Release 12.1(5)T
Note In all of the following configuration examples, the routers are configured with an 
interface vif1 command. This is a virtual interface that is similar to a loopback 
interface—it is a logical IP interface that is always up when the router is active. In 
addition, it must be configured so that the Cisco Hoot and Holler over IP packets that are 
locally mixed on the DSPs can be fast-switched along with the other data packets. This 
interface needs to reside on its own unique subnet, and that subnet should be included in 
the routing protocol updates (RIP, OSPF, and so on).
Voice Multicasting over an Ethernet LANFigure 4 shows the simplest configuration for voice multicasting over an Ethernet LAN. Two routers 
are connected to each other over the Ethernet LAN. One E&M phone is connected to each router.
Figure 4 Voice Multicasting over a LAN
In router Abbott (Figure 4), the phone is connected to voice port 2/0/0, using the 
router-slot/voice-slot/VIC-port numbering convention. This router is configured as in the following 
example:
hostname Abbott
!
ip multicast-routing
!
voice class permanent 1
signal timing oos timeout disabled
signal keepalive 65535
!
interface Vif1
 ip address 1.1.1.1 255.0.0.0
 ip pim sparse-dense-mode
!
interface Ethernet0/0
 ip address 3.3.3.1 255.0.0.0
 ip pim sparse-dense-mode
!
ip route 2.0.0.0 255.0.0.0 3.3.3.2
!
voice-port 2/0/0
 voice-class permanent 1
 connection trunk 111
 operation 4-wire
!         
dial-peer voice 1 voip
 destination-pattern 111
 session protocol multicast
 session target ipv4:237.111.0.111:22222
!
E&M VIC
2/0/0
Router 1
IP cloud
E&M VIC
3/1/1
Router 2
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