Specifications

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Cisco 1751 Router Software Configuration Guide
OL-1070-01
Configure IP Precedence for Dial Peers
Use the ip precedence command to give voice packets a higher priority than other IP data traffic. The
ip precedence command should also be used if RSVP is not enabled and you would like to give voice
packets a priority over other IP data traffic. IP precedence scales better than RSVP, but provides no
admission control.
To give real-time voice traffic precedence over other IP network traffic, use the following global
configuration commands:
In IP precedence, the numbers 1 through 5 identify classes for IP flows; the numbers 6 through 7 are
used for network and backbone routing and updates.
For example, to ensure that voice traffic associated with VoIP dial peer 103 is given a higher priority
than other IP network traffic, enter the following:
Router(config)# dial-peer voice 103 voip
Router(config-dial-peer)# ip precedence 5
In this example, when an IP call leg is associated with VoIP dial peer 103, all packets transmitted to the
IP network via this dial peer will have their precedence bits set to 5. If the networks receiving these
packets have been configured to recognize precedence bits, the packets are given priority over packets
with a lower configured precedence value.
Configure RSVP for Dial Peers
RSVP must be enabled at each LAN or WAN interface that voice packets will travel across. After
enabling RSVP, you must use the req-qos dial-peer configuration command to request an RSVP session
and configure the QoS for each VoIP dial peer. Otherwise, no bandwidth is reserved for voice traffic.
To configure controlled-load QoS for VoIP dial peer 108, enter the following global configuration
commands:
Router(config)# Dial-peer voice 108 voip
Router(config-dial-peer)# req-qos controlled-load
Router(config-dial-peer)# session target ipv4:10.0.0.8
In this example, every time a connection is made through VoIP dial peer 108, an RSVP reservation
request is made between the local router, all intermediate routers in the path, and the final destination
router.
Note We recommend that you select controlled-load for the requested QoS. The
controlled-load service uses admission (or capacity) control to ensure that preferential
service is received even when the bandwidth is overloaded.
Command Task
Step 1
dial-peer voice number voip Enter the dial peer configuration mode to configure a VoIP dial
peer.
Step 2
ip precedence number Select a precedence level for the voice traffic associated with that
dial peer.