Specifications

Frame Relay for Voice over IP Configuration Example
Voice over IP for the Cisco AS5300 13
Note We recommend FRF.12 fragmentation setup rules for Voice over IP connections over Frame
Relay. FRF.12 was implemented in the Cisco IOS Release 12.0(4)T. For more information, refer to
the Cisco IOS Release 12.0(4)T “Voice over Frame Relay using FRF.11 and FRF.12” feature
module.
Frame Relay for Voice over IP Configuration Example
For Frame Relay, it is customary to configure a main interface and several subinterfaces, one
subinterface per PVC. The following example configures a Frame Relay main interface and a
subinterface so that voice and data traffic can be successfully transported:
interface Serial0/0
ip mtu 300
no ip address
encapsulation frame-relay
no ip route-cache
no ip mroute-cache
fair-queue 64 256 1000
frame-relay ip rtp header-compression
interface Serial0/0.1 point-to-point
ip mtu 300
ip address 40.0.0.7 255.0.0.0
ip rsvp bandwidth 48 48
no ip route-cache
no ip mroute-cache
bandwidth 64
traffic-shape rate 32000 4000 4000
frame-relay interface-dlci 16
frame-relay ip rtp header-compression
In this configuration example, the main interface has been configured as follows:
• MTU size of IP packets is 300 bytes.
• No IP address is associated with this serial interface. The IP address must be assigned for the
subinterface.
• Encapsulation method is Frame Relay.
• Fair queueing is enabled.
• IP RTP header compression is enabled.
The subinterface has been configured as follows:
• MTU size is inherited from the main interface.
• IP address for the subinterface is specified.
• Bandwidth is set to 64 kbps.
• Generic traffic shaping is enabled with 32-kbps CIR where Bc = 4000 bits and Be = 4000 bits.
• Frame Relay DLCI number is specified.
• IP RTP header compression is enabled.
Note When traffic bursts over the CIR, output rate is held at the speed configured for the CIR (for
example, traffic will not go beyond 32 kbps if CIR is set to 32 kbps).