LiveNX IP SLA is a technology module that makes Cisco IOS IP Service Level Agreement (SLA) operations easily accessible for generating synthetic network traffic to monitor latency, loss, jitter, and MOS (for VoIP).
LiveNX SLA is part of the LiveNX software framework that enables IT engineers at all experience levels to perform advanced Cisco device operations quickly and easily on live networks. Its highly interactive graphical interface delivers the full functionality and flexibility of the device features without the need to learn and use Cisco device command lines.
About Cisco IOS IP SLA
Cisco IOS IP SLA is a capability embedded in most devices that run Cisco IOS software. Its service-level assurance metrics and methodology allows you to increase network reliability by verifying service guarantees with precise service-level assurance measurements. IP SLA can validate network performance, proactively identify network issues, and simplify the deployment of new IP services.
Cisco IOS IP SLAs generate synthetic test traffic in a continuous, reliable, and predictable manner to enable accurate measurement of network performance. This traffic can be sent across the network to measure performance among multiple network locations or across multiple network paths. IP SLA uses timestamp information to facilitate the calculation of performance metrics such as jitter, latency, network and server response times, packet loss, and Mean Opinion Score (MOS).
Key Features and Benefits
Ease of Use
LiveNX makes Cisco IP SLA easy to use. An intuitive graphical interface replaces complicated command lines, making on-the-fly test configuration and execution easy and understandable.
Reduces time required for network deployment, maintenance, and training, while improving network availability.
Built-In IP SLA Expertise
LiveNX IP SLA is based on Cisco best practices and an extensive knowledge base of Cisco IP SLA features and functions.
LiveNX provides graphical views of latency, loss, jitter, and MOS over IP SLA. It also displays real-time topological views and test status, as well as test results plotted historically on a timeline.
Test Traffic Generation
Generates and sends synthetic test traffic from the router for measuring network performance. Enables detailed editing of test configurations to simulate complex traffic patterns.
Start, stop, and edit traffic tests in real time.
LiveNX IP SLA is a software-based solution that requires no physical topology changes or service interruptions to install.
LiveNX QoS takes full advantage of existing Cisco device features, significantly reducing the need to purchase separate test networks and hardware-based test equipment, including traffic generators, far end-point probes, and analyzers.
Getting Started with LiveNX IP SLA
IP SLA Compatible Devices
The LiveNX IP SLA feature is capable of supporting Cisco devices that are IP SLA-enabled. The following is a list of Cisco devices that support IP SLA. A voice image is required for some platforms.
- Cisco 12000 Series Internet Routers
- Cisco 7500 Series Routers
- Cisco 7200 Series Routers
- Cisco 7000 Series Routers
- Cisco 6400 Series Broadband Aggregators
- Cisco 3900 Series Integrated Services Routers
- Cisco 3800 Series Integrated Services Routers
- Cisco 3700 Series Multiservice Access Routers
- Cisco 3600 Series Multiservice Platforms
- Cisco 3200 Series Mobile Access Routers
- Cisco 2900 Series Integrated Services Routers
- Cisco 2800 Series Integrated Services Routers
- Cisco 2600 Series Multiservice Platforms
- Cisco 2500 Series Routers
- Cisco 2000 Series Routers
- Cisco MWR 1900 Series Mobile Access Routers
- Cisco 1900 Series Integrated Services Routers
- Cisco 1800 Series Integrated Services Routers
- Cisco 1700 Series Access Routers
- Cisco 1600 Series Routers
- Cisco 1400 Series Routers
- Cisco 1000 Series Routers
- Cisco 800 Series Routers
- Cisco Catalyst 6500 Series Switches
- Cisco Catalyst 6000 Series Switches Module Switch Feature Card (MSFC)
- Cisco Catalyst 6000 Series Switches (running IOS)
- Cisco Catalyst 5000 Series Switches Router Switch Module (RSM)
- Cisco Catalyst 5000 Series Switches Router Switch Feature Card (RSFC)
- Cisco Catalyst 4200 Series Switches
- Cisco Catalyst 4000 Series Switches (running IOS)
- Cisco Catalyst 3750 Series Switches
- Cisco Catalyst 3560 Series Switches
- Cisco Catalyst 3500 Series Switches
- Cisco Catalyst 2900 Series Switches
Cisco IOS and Catalyst Operating System Version IP SLA Support
- IP SLA is available on all routing platforms, from the 800 series up to the 12000 series.
- IP SLA is available for 2900, 3500, 3700, 4000 (SUP4), and 6000 (MSFC or MWAM) series Catalyst switches.
- IP SLA is included in the IP feature set from 11.3 up to 12.2 and above.
- The IP voice or upper feature set is required, starting with IOS release 12.3T and all of 12.4 and above.
Network Device Considerations
For accurate time measurements, network devices must be synchronized with a common reference clock. This can be accomplished by using Network Time Protocol (NTP) synchronization with an NTP server, or by assigning one network device to function as a time master server.
The accuracy of one key latency metric that is directly linked to NTP is the LiveNX UDP, jitter, one-way delay test operation. This IP SLA operation can test and report the one-way delay for both the outbound and return paths between two points on the network. Here, the data returned by IP SLAs will depend directly on the engineering design, deployment, and accuracy of NTP in your networks.
Normal scheduling of IP SLA allows for one operation at a time. If no start time is specified, the operation starts immediately. This is not a problem if a single operation is defined and activated manually by an operator using the CLI. The situation changes with LiveNX if multiple operations are defined without specific start times and the network device reboots.
For example, if 1,000 operations were defined for one device without staggered start times and a reboot occurs, all of these operations would start instantly and simultaneously. This would result in a CPU spike at the device and potentially a sudden burst of IP SLA test traffic in the network. Either of these effects can have a negative impact on network efficiency and measurement accuracy.
Configuring LiveNX IP SLA
Below are examples of some generalized performance metrics recommended by Cisco for various types of traffic:
Setup Quick Test Wizard
Network verification and testing can be set up quickly using the LiveNX IP SLA Setup Quick Test wizard. The quick test can be invoked by clicking the Quick Test or right clicking on the particular interface you want to generate the IPSLA test stream from.
The following example goes through setting up a test to measure jitter, latency, and loss between two routers.
- In the IP SLA tab toolbar, click Setup Quick Test to display the Setup Quick Test dialog box. If the Log In Required window appears, you must log in with Admin or Full Config credentials.
Select the source router or switch from the Device drop-down list of available devices.
The Entry ID number is filled in automatically. This is a unique number that identifies the test in the Cisco router.
Select Test type. Options are DHCP, DNS, ICMP Echo, FTP, HTTP, Jitter, Video, UDP Echo, Path Jitter, and Path Echo.
“Echo” refers to the receiving router sending back the data unchanged to the sending router, and “jitter” indicates variations in delay times between multiple UDP Echo packets. “Path” refers to the display of the path the test traffic will take through the network.
Path Echo and Path Jitter tests measure the time between sending and receiving acknowledgment of user Datagram Protocol (UDP) Echo (port 7) packets. This is useful in determining round-trip delay for programs using UDP to communicate over the network.
Video is a new test function also known as Medianet IPSLA Video Operation. This test type is capable of generating synthetic Telepresence, IPTV and IP video surveillance traffic.
Enter the optional Tag value to use as the name, label, or description of the test.
Select the Source address from the dropdown list of interfaces. All existing interfaces for the device should be listed.
Select the Destination address (IP address or hostname) by clicking on the desired destination device interface in the IP SLA topology view.
Enable IP SLA polling for both devices by going to File > Mange Devices. Select the appropriate check boxes in the Poll and IPSLA column. Polling must be enabled before IP SLA test results will appear.
To monitor this test, click Show Test Status in the IP SLA tab toolbar. This will bring up the Test Status window that will show you statistics for latency, jitter, and loss.
• The test will run continuously by default until ended.
• Statistics will take one polling interval (default is 60 seconds) to refresh.
Additional detailed test information can be accessed by clicking on the originating router while in the IP SLA view. This displays a set of graph for Latency, Jitter, Packet Loss and MOS scores as shown below.
By selecting the viewing mode, various different sets of graphs can be shown that are appropriate for the test being run.
3. The IP address in the Destination/URL field can be changed to a user-defined value by the Edit IP Mapping feature.
By selecting Tools > Edit IP Mappings described in Chapter 11, select Add and then type in a user-defined Name and the desired IP Address. The new user-defined value is displayed in the Destination/URL field.
For extended test coverage and scheduling capability, access configuration options from the IP SLA menu, or right-click on the network device from which the test will be started.
The manage test window allows you to create, delete, copy and group tests. The main window is shown below.
Adding a new test is done by clicking Add Test, which brings up a dialog with basic test parameters.
Once a test is created, it can be edited using either the basic or advanced mode. Click Basic Mode or Advanced Mode to toggle between basic and advanced configuration modes. Parameters edited in one mode will persist in the other mode; validation is also enforced in both modes. In Basic Mode, required fields are denoted with an asterisk (*).
Save to Device and Preview CLI are enabled when changes have been made and all changes are valid. View Errors will be enabled if there are any validation errors. Click View Errors to display a list of all errors.
Refer to the Cisco reference manual for descriptions of all Path Echo configuration parameters.
In the system topology view, Path Echo test results are displayed in visual form, delivering rich context for instant understanding. Colored icons indicate operating success or failure status quickly and easily for each test.