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Configure Frame Relay for Voice over IP
Configure Custom Queuing
Some QoS features, such as IP RTP reserve and custom queuing, are based on the transport protocol and the associated port number.
16384 = 4(number of voice ports in the Cisco 3600 series router)
Custom Queuing and other methods for identifying high priority streams should be configured for these port ranges. For more information about custom queuing, refer to the “Performing Basic System Management” chapter in the Configuration Fundamentals Configuration Guide.
Configure Weighted Fair Queuing
Weighted fair queuing ensures that queues do not starve for bandwidth and that traffic gets predictable service.
In general, weighted fair queuing is used in conjunction with Multilink PPP with interleaving and RSVP or IP Precedence to ensure that voice packet delivery. Use weighted fair queuing with Multilink PPP to define how data will be managed; use RSVP or IP Precedence to give priority to voice packets. For more information about weighted fair queuing, refer to the “Performing Basic System Management” chapter in the Configuration Fundamentals Configuration Guide.
Configure Frame Relay for Voice over IP
You need to take certain factors into consideration when configuring Voice over IP for it to run smoothly over Frame Relay. A public Frame Relay cloud provides no guarantees for QoS. For
For Frame Relay links with slow output rates (less than or equal to 64 kbps) where data and voice are being transmitted over the same PVC, we recommend the following solutions:
•Separate DLCIs for voice and
—Apply adaptive traffic shaping to both DLCIs.
—Use RSVP or IP Precedence to prioritize voice traffic.
—Use compressed RTP to minimize voice packet size.
—Use weighted fair queuing to manage voice traffic.
•Lower MTU
Note Some applications do not support a smaller MTU size. If you decide to lower MTU size, use the ip mtu command; this command affects only IP traffic.