- IP SLAs Overview
- Configuring IP SLAs UDP Jitter Operations
- Configuring IP SLAs UDP Jitter Operations for VoIP
- Configuring IP SLAs UDP Echo Operations
- Configuring IP SLAs HTTP Operations
- Configuring IP SLAs TCP Connect Operations
- Configuring Cisco IP SLAs ICMP Jitter Operations
- Configuring IP SLAs ICMP Echo Operations
- Configuring IP SLAs ICMP Path Echo Operations
- Configuring IP SLAs ICMP Path Jitter Operations
- Configuring IP SLAs FTP Operations
- Configuring IP SLAs DNS Operations
- Configuring IP SLAs DHCP Operations
- Configuring an IP SLAs Multioperation Scheduler
- Configuring Proactive Threshold Monitoring for IP SLAs Operations
- Finding Feature Information
- Prerequisites for IP SLAs UDP Jitter Operations
- Information About IP SLAs UDP Jitter Operations
- How to Configure IP SLAs UDP Jitter Operations
Configuring IP SLAs UDP Jitter Operations
This document describes how to configure an IP Service Level Agreements (SLAs) UDP jitter operation to analyze round-trip delay, one-way delay, one-way jitter, one-way packet loss, and connectivity in networks that carry UDP traffic in IPv4 or IPv6 networks. This module also explains how the data gathered using the UDP jitter operation can be displayed and analyzed using Cisco software commands.
- Finding Feature Information
- Prerequisites for IP SLAs UDP Jitter Operations
- Information About IP SLAs UDP Jitter Operations
- How to Configure IP SLAs UDP Jitter Operations
- Verifying IP SLAs UDP Jitter Operations
- Configuration Examples for IP SLAs UDP Jitter Operations
- Additional References for IP SLAs UDP Jitter Operations
- Feature Information for IP SLAs UDP Jitter Operations
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.
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.
Prerequisites for IP SLAs UDP Jitter Operations
Time synchronization, such as that provided by the Network Time Protocol (NTP), is required between the source and the target device to provide accurate one-way delay (latency) measurements. To configure NTP on source and target devices, perform the tasks in the “Performing Basic System Management” chapter of the Basic System Management Configuration Guide. Time synchronization is not required for one-way jitter and packet loss measurements. If time is not synchronized between source and target devices, one-way jitter and packet loss data are returned, but values of “0” are returned for the one-way delay measurements provided by the UDP jitter operation.
Before configuring any IP Service Level Agreements (SLAs) application, use the show ip sla application command to verify that the operation type is supported on the software image.
Information About IP SLAs UDP Jitter Operations
IP SLAs UDP Jitter Operation
The IP Service Level Agreements (SLAs) UDP jitter operation diagnoses network suitability for real-time traffic applications such as VoIP, video over IP, or real-time conferencing.
Jitter means inter-packet delay variance. When multiple packets are sent consecutively from a source to a destination, for example, 10 ms apart, and if the network is behaving ideally, the destination should receive the packets 10 ms apart. But if there are delays in the network (like queuing, arriving through alternate routes, and so on) the arrival delay between packets might be greater than or less than 10 ms. Using this example, a positive jitter value indicates that packets arrived greater than 10 ms apart. If packets arrive 12 ms apart, then positive jitter is 2 ms; if packets arrive 8 ms apart, negative jitter is 2 ms. For delay-sensitive networks like VoIP, positive jitter values are undesirable, and a jitter value of 0 is ideal.
However, the IP SLAs UDP jitter operation does more than just monitor jitter. As the UDP jitter operation includes data returned by the IP SLAs UDP operation, the UDP jitter operation can be used as a multipurpose data gathering operation. The packets that IP SLAs generate carry packet-sending and receiving sequence information, and sending and receiving time stamps from the source and the operational target. Based on this information, UDP jitter operations are capable of measuring the following:
Per-direction jitter (source to destination and destination to source)
Per-direction packet loss
Per-direction delay (one-way delay)
Round-trip delay (average round-trip time)
As paths for sending and receiving data may be different (asymmetric), the per-direction data allows you to more readily identify where congestion or other problems are occurring in the network.
The UDP jitter operation functions by generating synthetic (simulated) UDP traffic. Asymmetric probes support custom-defined packet sizes per direction with which different packet sizes can be sent in request packets (from the source device to the destination device) and in response packets (from the destination device to the source device).
The UDP jitter operation sends N number of UDP packets, each of size S, T milliseconds apart, from a source device to a destination device, at a given frequency of F. In response, UDP packets of size P is sent from the destination device to the source device. By default, ten packet frames (N), each with a payload size of 10 bytes (S), are generated every 10 ms (T), and the operation is repeated every 60 seconds (F). Each of these parameters is user-configurable, so as to best simulate the IP service that you provide, as shown in the table below.
UDP Jitter Operation Parameter |
Default |
Configuration Commands |
||
---|---|---|---|---|
Number of packets (N) |
10 packets |
udp-jitter num-packets |
||
Payload size per request packet (S) |
10 bytes |
request-data-size |
||
Payload size per response packet (P) |
The default response data size varies depending on the type of IP SLAs operation configured.
|
response-data-size |
||
Time between packets, in milliseconds (T) |
10 ms |
udp-jitter interval |
||
Elapsed time before the operation repeats, in seconds (F) |
60 seconds |
frequency (IP SLA) |
The IP SLAs operations function by generating synthetic (simulated) network traffic. A single IP SLAs operation (for example, IP SLAs operation 10) repeats at a given frequency for the lifetime of the operation.
How to Configure IP SLAs UDP Jitter Operations
- Configuring the IP SLAs Responder on a Destination Device
- Configuring and Scheduling a UDP Jitter Operation on a Source Device
- Scheduling IP SLAs Operations
Configuring the IP SLAs Responder on a Destination Device
Note | A responder should not configure a permanent port for a sender. If the responder configures a permanent port for a sender, even if the packets are successfully sent (no timeout or packet-loss issues), the jitter value is zero. |
DETAILED STEPS
Configuring and Scheduling a UDP Jitter Operation on a Source Device
- Configuring a Basic UDP Jitter Operation on a Source Device
- Configuring a UDP Jitter Operation with Additional Characteristics
Configuring a Basic UDP Jitter Operation on a Source Device
1.
enable
2.
configure
terminal
3.
ip
sla
operation-number
4.
udp-jitter {destination-ip-address |
destination-hostname}
destination-port [source-ip {ip-address |
hostname}] [source-port
port-number] [control {enable |
disable}] [num-packets
number-of-packets] [interval
interpacket-interval]
5.
frequency
seconds
6.
end
7.
show
ip
sla
configuration
[operation-number]
DETAILED STEPS
To configure the percentile option for your operation, see the “Configuring the IP SLAs—Percentile Support for Filtering Outliers” module.
Configuring a UDP Jitter Operation with Additional Characteristics
Before configuring a UDP jitter operation on a source device, the IP SLAs Responder must be enabled on the target device (the operational target). The IP SLAs Responder is available only on Cisco IOS software-based devices. To enable the Responder, perform the task in the “Configuring the IP SLAs Responder on the Destination Device” section.
1.
enable
2.
configure
terminal
3.
ip
sla
operation-number
4.
udp-jitter {destination-ip-address |
destination-hostname}
destination-port [source-ip {ip-address |
hostname}] [source-port
port-number] [control {enable |
disable}] [num-packets
number-of-packets] [interval
interpacket-interval]
5.
history
distributions-of-statistics-kept
size
6.
history
enhanced
[interval
seconds] [buckets
number-of-buckets]
7.
frequency
seconds
8.
history
hours-of-statistics-kept
hours
9.
owner
owner-id
10.
request-data-size
bytes
11.
response-data-size
bytes
12.
history
statistics-distribution-interval
milliseconds
13.
tag
text
14.
threshold
milliseconds
15.
timeout
milliseconds
16.
Enter one of the following commands:
17.
flow-label
number
18.
verify-data
19.
vrf
vrf-name
20.
end
21.
show
ip
sla
configuration
[operation-number]
DETAILED STEPS
To configure the percentile option for your operation, see the “Configuring the IP SLAs—Percentile Support for Filtering Outliers” module.
Scheduling IP SLAs Operations
- All IP Service Level Agreements (SLAs) operations to be scheduled must be already configured.
- The frequency of all operations scheduled in a multioperation group must be the same.
- The list of one or more operation ID numbers to be added to a multioperation group must be limited to a maximum of 125 characters in length, including commas (,).
- ip sla schedule operation-number [life {forever | seconds}] [start-time {[hh:mm:ss] [month day | day month] | pending | now | after hh:mm:ss}] [ageout seconds] [recurring]
- ip sla group schedule group-operation-number operation-id-numbers {schedule-period schedule-period-range | schedule-together} [ageout seconds] [frequency group-operation-frequency] [life {forever | seconds}] [start-time {hh:mm [:ss] [month day | day month] | pending | now | after hh:mm [:ss]}]
1.
enable
2.
configure
terminal
3.
Enter one of
the following commands:
4.
end
5.
show
ip
sla
group
schedule
6.
show
ip
sla
configuration
DETAILED STEPS
Troubleshooting Tips
If the IP Service Level Agreements (SLAs) operation is not running and not generating statistics, add the verify-data command to the configuration (while configuring in IP SLA configuration mode) to enable data verification. When data verification is enabled, each operation response is checked for corruption. Use the verify-data command with caution during normal operations because it generates unnecessary overhead.
Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an IP SLAs operation.
What to Do Next
To add proactive threshold conditions and reactive triggering for generating traps (or for starting another operation) to an IP Service Level Agreements (SLAs) operation, see the “Configuring Proactive Threshold Monitoring” section.
Verifying IP SLAs UDP Jitter Operations
1.
enable
2.
show
ip
sla
configuration
3.
show ip sla group schedule
4.
show ip sla statistics
5.
show ip sla statistics 2 details
DETAILED STEPS
Configuration Examples for IP SLAs UDP Jitter Operations
Example: Configuring a UDP Jitter Operation
In the following example, two operations are configured as UDP jitter operations, with operation 2 starting five seconds after the first operation. Both operations will run indefinitely.
configure terminal ip sla 1 udp-jitter 192.0.2.115 65051 num-packets 20 request-data-size 160 tos 128 frequency 30 ip sla schedule 1 start-time after 00:05:00 ip sla 2 udp-jitter 192.0.2.115 65052 num-packets 20 interval 10 request-data-size 20 tos 64 frequency 30 ip sla schedule 2 start-time after 00:05:05
Enter the following command on the target (destination) device to temporarily enable the IP SLAs responder functionality on a Cisco device in response to control messages from the source device.
ip sla responder
Additional References for IP SLAs UDP Jitter Operations
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Cisco IOS IP SLAs commands |
MIBs
MIBs |
MIBs Link |
---|---|
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for IP SLAs UDP Jitter Operations
Feature Name |
Releases |
Feature Information |
---|---|---|
IP SLAs—UDP Jitter Operation |
Cisco IOS XE 3.2SE |
The IP SLAs UDP jitter operation allows you to measure round-trip delay, one-way delay, one-way jitter, one-way packet loss, and connectivity in networks that carry UDP traffic. |
IP SLAs for IPv6 (UDP Jitter, UDP Echo, ICMP Echo, TCP Connect) |
Cisco IOS XE 3.2SE |
The IP SLAs for IPv6 (UDP Jitter, UDP Echo, ICMP Echo, TCP Connect) feature adds support for operability in IPv6 networks. |
IP SLAs—Asymmetric Probe Support for UDP Jitter |
Cisco IOS XE 3.2SE |
The IP SLAs—Asymmetric Probe Support for UDP Jitter feature supports the configuration of custom-defined packet sizes in response packets. The following command was introduced: response-data-size. |