- Wide-Area Networking Overview
- Configuring Frame Relay
- Frame Relay 64-Bit Counters
- Frame Relay Queueing and Fragmentation at the Interface
- Frame Relay PVC Bundles with QoS Support for IP and MPLS
- Frame Relay PVC Interface Priority Queueing
- Frame Relay IP RTP Priority
- PPP over Frame Relay
- Multilink Frame Relay FRF.16.1
- Distributed Multilink Frame Relay FRF.16
Contents
- Frame Relay IP RTP Priority
- Finding Feature Information
- Feature Overview
- Benefits
- Related Features and Technologies
- Related Documents
- Supported Platforms
- Supported Standards and MIBs and RFCs
- Prerequisites
- Configuration Tasks
- Configuring Frame Relay IP RTP Priority
- Verifying Frame Relay IP RTP Priority
- Monitoring and Maintaining Frame Relay IP RTP Priority
- Configuration Examples
- Frame Relay IP RTP Priority Configuration Example
Frame Relay IP RTP Priority
This feature module describes the Frame Relay IP RTP Priority feature.
- Finding Feature Information
- Feature Overview
- Supported Platforms
- Supported Standards and MIBs and RFCs
- Prerequisites
- Configuration Tasks
- Monitoring and Maintaining Frame Relay IP RTP Priority
- Configuration Examples
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Overview
The Frame Relay IP RTP Priority feature provides a strict priority queueing scheme on a Frame Relay permanent virtual circuit (PVC) for delay-sensitive data such as voice. Voice traffic can be identified by its Real-Time Transport Protocol (RTP) port numbers and classified into a priority queue configured by the frame-relay ip rtp prioritycommand. The result of using this feature is that voice is serviced as strict priority in preference to other nonvoice traffic.
This feature extends the functionality offered by the ip rtp priority command by supporting Frame Relay PVCs. This feature allows you to specify a range of User Datagram Protocol (UDP) ports whose voice traffic is guaranteed strict priority service over any other queues or classes using the same output interface. Strict priority means that if packets exist in the priority queue, they are dequeued and sent first--that is, before packets in other queues are dequeued.
Benefits
The strict priority queueing scheme allows delay-sensitive data such as voice to be dequeued and sent first--that is, before packets in other queues are dequeued. Delay-sensitive data is given preferential treatment over other traffic. This process is performed on a per-PVC basis, rather than at the interface level.
Related Features and Technologies
The Frame Relay IP RTP Priority feature is related to the following features:
- IP RTP Priority
- Class-based weighted fair queueing (CBWFQ)
- Priority queueing
- Weighted fair queueing (WFQ)
Related Documents
- Quality of Service Solutions Configuration Guide , Cisco IOS Release 12.0
- Quality of Service Solutions Command Reference , Cisco IOS Release 12.0
- Class-Based Weighted Fair Queueing
- IP RTP Priority
Supported Platforms
- Cisco 1003
- Cisco 1004
- Cisco 1005
- Cisco 1600 series
- Cisco 2500 series
- Cisco 2600 series
- Cisco 3600 series
- Cisco 3800 series
- Cisco 4000 series (Cisco 4000, 4000-M, 4500, 4500-M, 4700, 4700-M)
- Cisco 5200 series
- Cisco 7000 series
- Cisco 7200 series
- Cisco 7500 series
This feature runs on the platforms listed. However, it is most useful on voice supported platforms, such as the Cisco 2600 series, Cisco 3600 series, Cisco 7200 series, and Cisco 7500 Route Switch Processor (RSP) series.
Supported Standards and MIBs and RFCs
Standards
None
MIBs
No new or modified MIBs are supported by this feature.
RFCs
None
Prerequisites
Frame Relay traffic shaping (FRTS) and Frame Relay Fragmentation (FRF.12) must be configured before the Frame Relay IP RTP Priority feature is used.
Configuration Tasks
Configuring Frame Relay IP RTP Priority
To reserve a strict priority queue on a Frame Relay PVC for a set of RTP packet flows belonging to a range of UDP destination ports, use the following command in map-class configuration mode.
 Note | Because the frame-relay ip rtp priority command gives absolute priority over other traffic, it should be used with care. In the event of congestion, if the traffic exceeds the configured bandwidth, then all the excess traffic is dropped. |
|
Command |
Purpose |
|---|---|
Router(config-map-class)# frame-relay ip rtp priority starting-rtp-port-number port-number-range bandwidth |
Reserves a strict priority queue for a set of RTP packet flows belonging to a range of UDP destination ports. |
Verifying Frame Relay IP RTP Priority
To verify the Frame Relay IP RTP Priority feature, use one of the following commands in EXEC mode:
|
Command |
Purpose |
|---|---|
Router# show frame relay pvc
|
Displays statistics about PVCs for Frame Relay interfaces. |
Router# show queue interface-type interface-number |
Displays fair queueing configuration and statistics for a particular interface. |
Router# show traffic-shape queue
|
Displays information about the elements queued at a particular time at the VC data link connection identifier (DLCI) level. |
Monitoring and Maintaining Frame Relay IP RTP Priority
To tune your RTP bandwidth or decrease RTP traffic if the priority queue is experiencing drops, use the following command in EXEC mode:
|
Command |
Purpose |
|---|---|
Router# debug priority
|
Displays priority queueing output if packets are dropped from the priority queue. |
Configuration Examples
Frame Relay IP RTP Priority Configuration Example
The following example first configures the Frame Relay map class called voip and then applies the map class to PVC 100 to provide strict priority service to matching RTP packets:
map-class frame-relay voip frame-relay cir 256000 frame-relay bc 2560 frame-relay be 600 frame-relay mincir 256000 no frame-relay adaptive-shaping frame-relay fair-queue frame-relay fragment 250 frame-relay ip rtp priority 16384 16380 210 interface Serial5/0 ip address 10.10.10.10 255.0.0.0 no ip directed-broadcast encapsulation frame-relay no ip mroute-cache load-interval 30 clockrate 1007616 frame-relay traffic-shaping frame-relay interface-dlci 100 class voip frame-relay ip rtp header-compression frame-relay intf-type dce
In this example, RTP packets on PVC 100 with UDP ports in the range 16384 to 32764 will be matched and given strict priority service.