- IP SLAs Overview
- Configuring IP SLAs UDP Jitter Operations
- Configuring IP SLAs LSP Health Monitor Operations
- Configuring IP SLAs for Metro-Ethernet
- Configuring IP SLAs UDP Echo Operations
- Configuring IP SLAs HTTP Operations
- Configuring IP SLAs TCP Connect 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 IP SLAs DLSw+ Operations
- Configuring an IP SLAs Multioperation Scheduler
- Configuring Proactive Threshold Monitoring for IP SLAs Operations
- Configuring IP SLA - Percentile Support for Filtering Outliers
- Finding Feature Information
- Prerequisites for ICMP Path Jitter Operations
- Restrictions for ICMP Path Jitter Operations
- Information About IP SLAs ICMP Path Jitter Operations
- How to Configure the IP SLAs ICMP Path Jitter Operation
Configuring IP SLAs ICMP Path Jitter Operations
This document describes how to configure an IP Service Level Agreements (SLAs) Internet Control Message Protocol (ICMP) Path Jitter operation to monitor hop-by-hop jitter (inter-packet delay variance). This document also demonstrates how the data gathered using the Path Jitter operations can be displayed and analyzed using Cisco commands.
- Finding Feature Information
- Prerequisites for ICMP Path Jitter Operations
- Restrictions for ICMP Path Jitter Operations
- Information About IP SLAs ICMP Path Jitter Operations
- How to Configure the IP SLAs ICMP Path Jitter Operation
- Configuration Examples for IP SLAs ICMP Path Jitter Operations
- Additional References
- Feature Information for IP SLAs ICMP Path 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 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.
Prerequisites for ICMP Path Jitter Operations
Before configuring any IP SLAs application, you can use the show ip sla application command to verify that the operation type is supported on your software image.
In contrast with other IP SLAs operations, the IP SLAs Responder does not have to be enabled on either the target device or intermediate devices for Path Jitter operations. However, the operational efficiency may improve if you enable the IP SLAs Responder.
Restrictions for ICMP Path Jitter Operations
IP SLAs - ICMP Path Jitter is ICMP-based. ICMP-based operations can compensate for source processing delay but cannot compensate for target processing delay. For more robust monitoring and verifying, we recommend that you use the IP SLAs UDP Jitter operation.
The jitter values obtained using IP SLAs - ICMP Path Jitter are approximates because ICMP does not provide the capability to embed processing times on devices in the packet. If the target device does not place ICMP packets as the highest priority, then the device will not respond properly. ICMP performance also can be affected by the configuration of priority queueing on the device and by ping response.
A path jitter operation does not support hourly statistics and hop information.
Unlike other IP SLAs operations, the ICMP Path Jitter operation is not supported in the RTTMON MIB. Path jitter operations can only be configured using Cisco commands and statistics can only be returned using the show ip sla commands.
IP SLAs - Path Jitter does not support the IP SLAs History feature (statistics history buckets) because of the large data volume involved with jitter operations.
The following commands, available in path jitter configuration mode, do not apply to path jitter operations:
Information About IP SLAs ICMP Path Jitter Operations
ICMP Path Jitter Operation
IP SLAs - ICMP Path Jitter provides hop-by-hop jitter, packet loss, and delay measurement statistics in an IP network. Path jitter operations function differently than the standard UDP Jitter operation, which provides total one-way data and total round-trip data.
An ICMP Path Jitter operation can be used a supplement to the standard UDP Jitter operation. For example, results from a UDP Jitter operation may indicate unexpected delays or high jitter values; an ICMP Path Jitter operation could then be used to troubleshoot the network path and determine if traffic is bottlenecking in a particular segment along the transmission path.
The operation first discovers the hop-by-hop IP route from the source to the destination using a traceroute utility, and then uses ICMP echoes to determine the response times, packet loss and approximate jitter values for each hop along the path. The jitter values obtained using IP SLAs - ICMP Path Jitter are approximates because ICMP only provides round trip times.
ICMP Path Jitter operations function by tracing the IP path from a source device to a specified destination device, then sending N number of Echo probes to each hop along the traced path, with a time interval of T milliseconds between each Echo probe. The operation as a whole is repeated at a frequency of once every F seconds. The attributes are user-configurable, as shown here:
How to Configure the IP SLAs ICMP Path Jitter Operation
- Configuring the IP SLAs Responder on a Destination Device
- Configuring an ICMP Path Jitter Operation on the Source Device
- Scheduling IP SLAs Operations
Configuring the IP SLAs Responder on a Destination Device
 Note | An IP SLAs Responder is not required on either the target device or intermediate devices for path jitter operations. However, operational efficiency may improve if you enable the IP SLAs Responder. |
The networking device to be used as the responder must be a Cisco device and you must have connectivity to that device through the network.
1.
enable
2.
configure
terminal
3.
ip
sla
responder
4.
exit
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
sla
responder
Example: Example: Device(config)# ip sla responder |
(Optional) Temporarily enables IP SLAs Responder functionality on a Cisco device in response to control messages from source. |
| Step 4 |
exit
Example: Device(config)# exit |
(Optional) Exits global configuration mode and returns to privileged EXEC mode. |
Configuring an ICMP Path Jitter Operation on the Source Device
Perform only one of the following procedures in this section:
- Configuring a Basic ICMP Path Jitter Operation
- Configuring an ICMP Path Jitter Operation with Additional Parameters
Configuring a Basic ICMP Path Jitter Operation
1.
enable
2.
configure
terminal
3.
ip
sla
operation-number
4.
path-jitter
{destination-ip-address |
destination-hostname} [source-ip {ip-address |
hostname}] [num-packets
packet-number] [interval
milliseconds] [targetOnly]
5.
frequency
seconds
6.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
sla
operation-number
Example: Device(config)# ip sla 10 |
Begins configuration for an IP SLAs operation and enters IP SLA configuration mode. |
| Step 4 |
path-jitter
{destination-ip-address |
destination-hostname} [source-ip {ip-address |
hostname}] [num-packets
packet-number] [interval
milliseconds] [targetOnly]
Example: Device(config-ip-sla)# path-jitter 172.31.1.129 source-ip 10.2.30.1 num-packets 12 interval 22 |
Enters IP SLA Path Jitter configuration mode for configuring an ICMP Path Jitter operation. |
| Step 5 |
frequency
seconds
Example: Device(config-ip-sla-pathJitter)# frequency 30 |
(Optional) Sets the rate at which a specified IP SLAs operation repeats. |
| Step 6 |
end
Example: Device(config-ip-sla-pathJitter)# end |
Exits to privileged EXEC mode. |
Example
In the following example, the targetOnly keyword is used to bypass the hop-by-hop measurements. With this version of the command, echo probes will be sent to the destination only.
Device(config)# ip sla 1 Device(config-ip-sla)# path-jitter 172.17.246.20 num-packets 50 interval 30 targetOnly
Configuring an ICMP Path Jitter Operation with Additional Parameters
1.
enable
2.
configure
terminal
3.
ip
sla
operation-number
4.
path-jitter
{destination-ip-address |
destination-hostname} [source-ip {ip-address |
hostname}] [num-packets
packet-number] [interval
milliseconds] [targetOnly]
5.
frequency
seconds
6.
owner
owner-id
7.
request-data-size
bytes
8.
tag
text
9.
timeout
milliseconds
10.
vrf
vrf-name
11.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
sla
operation-number
Example: Device(config)# ip sla 10 |
Begins configuration for an IP SLAs operation and enters IP SLA configuration mode. |
| Step 4 |
path-jitter
{destination-ip-address |
destination-hostname} [source-ip {ip-address |
hostname}] [num-packets
packet-number] [interval
milliseconds] [targetOnly]
Example: Device(config-ip-sla)# path-jitter 172.31.1.129 source-ip 10.2.30.1 num-packets 12 interval 22 |
Enters IP SLA Path Jitter configuration mode for defing an ICMP Path Jitter operation. |
| Step 5 |
frequency
seconds
Example: Device(config-ip-sla-pathJitter)# frequency 30 |
(Optional) Sets the rate at which a specified IP SLAs operation repeats. |
| Step 6 |
owner
owner-id
Example: Device(config-ip-sla-pathJitter)# owner admin |
(Optional) Configures the Simple Network Management Protocol (SNMP) owner of an IP SLAs operation. |
| Step 7 |
request-data-size
bytes
Example: Device(config-ip-sla-pathJitter)# request-data-size 64 |
(Optional) Sets the protocol data size in the payload of an IP SLAs operation's request packet. |
| Step 8 |
tag
text
Example: Device(config-ip-sla-pathJitter)# tag TelnetPollServer1 |
(Optional) Creates a user-specified identifier for an IP SLAs operation. |
| Step 9 |
timeout
milliseconds
Example: Device(config-ip-sla-pathJitter)# timeout 10000 |
(Optional) Sets the amount of time an IP SLAs operation waits for a response from its request packet. |
| Step 10 |
vrf
vrf-name
Example: Device(config-ip-sla-pathJitter)# vrf vpn-A |
(Optional) Allows monitoring within Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs) using IP SLAs operations. |
| Step 11 |
end
Example: Device(config-ip-sla-pathJitter)# end |
Exits to privileged EXEC mode. |
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
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 | Enter one of the following commands:
Example: Device(config)# ip sla schedule 10 life forever start-time now Device(config)# ip sla schedule 10 schedule-period frequency Device(config)# ip sla group schedule 1 3,4,6-9 life forever start-time now Device(config)# ip sla schedule 1 3,4,6-9 schedule-period 50 frequency range 80-100 | |
| Step 4 |
end
Example: Device(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
| Step 5 |
show
ip
sla
group
schedule
Example: Device# show ip sla group schedule |
(Optional) Displays IP SLAs group schedule details. |
| Step 6 |
show
ip
sla
configuration
Example: Device# show ip sla configuration |
(Optional) Displays IP SLAs configuration details. |
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.
Configuration Examples for IP SLAs ICMP Path Jitter Operations
Example Configuring a Path Jitter Operation
The following example shows the output when the ICMP Path Jitter operation is configured. Because the path jitter operation does not support hourly statistics and hop information, the output for the show ip sla statistics command for the path jitter operation displays only the statistics for the first hop.
The following example shows the output when the ICMP Path Jitter operation is configured.
Device# configure terminal
Device(config)# ip sla 15011
Device(config-sla-monitor)# path-jitter 10.222.1.100 source-ip 10.222.3.100 num-packets 20
Device(config-sla-monitor-pathJitter)# frequency 30
Device(config-sla-monitor-pathJitter)# exit
Device(config)# ip sla schedule 15011 life forever start-time now
Device(config)# exit
Device# show ip sla statistics 15011
Round Trip Time (RTT) for Index 15011
Latest RTT: 1 milliseconds
Latest operation start time: 15:37:35.443 EDT Mon Jun 16 2008
Latest operation return code: OK
---- Path Jitter Statistics ----
Hop IP 10.222.3.252:
Round Trip Time milliseconds:
Latest RTT: 1 ms
Number of RTT: 20
RTT Min/Avg/Max: 1/1/3 ms
Jitter time milliseconds:
Number of jitter: 2
Jitter Min/Avg/Max: 2/2/2 ms
Packet Values:
Packet Loss (Timeouts): 0
Out of Sequence: 0
Discarded Samples: 0
Operation time to live: Forever
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
Cisco IOS IP SLAs commands |
Standards and RFCs
|
Standard/RFC |
Title |
|---|---|
|
RFC 18891 |
RTP: A Transport Protocol for Real-Time Applications ; see the section “Estimating the Interarrival Jitter” |
MIBs
|
MIBs |
MIBs Link |
|---|---|
|
MIB support for the Path Jitter operation is not provided. |
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 ICMP Path Jitter Operations
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
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 Name |
Releases |
Feature Information |
|---|---|---|
|
IP SLAs Path Jitter Operation |
The Cisco IOS IP SLAs Internet Control Message Protocol (ICMP) path jitter operation allows you to measure hop-by-hop jitter (inter-packet delay variance). |
|
|
IPSLA 4.0 - IP v6 phase2 |
Support was added for operability in IPv6 networks. The following commands are introduced or modified: path- jitter, show ip sla configuration, show ip sla summary. |
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