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IP SLA Video Operation – A powerful tool to mimic the real traffic demands on your network

With video increasingly becoming part of how you collaborate, you need to consider the impact of this incremental video on your network. Video brings many new challenges in order to meet user expectations for a flawless quality of experience. So is your network ready for rich media?

IP SLA video operation answers this question by synthetically generating traffic  mimicking real application traffic. The ability to generate realistic RTP stream similar to real life Cisco TelePresence allow you to stress the network and assess the demands these applications will impose on your network. Each type of media application can be expressed for the synthetic media generation system by media application profiles that contain personalities which incorporate characteristics such as bit rate, burst sizes, inter-packet-gaps, etc. These application profiles allow, for example, a catalyst switch to simulate the video playout from multiple places in the network. There may be multiple personalities based on different software versions or configurations of the media application. Cisco will make a set of comprehensive media application profiles available for download. IP SLA video operation, an enhancement to IP SLA, was announced on April 6, 2011 at ISC West in Las Vegas and is first introduced in IOS 12.2(58) SE on Cisco Catalyst 3750 and 3560 series switches. Over time, more products will be implementing this new operation.

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Mediascope

March 29, 2011 at 9:25 am PST

A few weeks ago, we introduced a new tool for network operators called mediatrace. On the router and switches, a mediatrace report presents several stanzas of data collected along a particular path. While the report is useful, there is a very high information density and the network operator could overlook an important item at a casual glance.

Mediascope was created as an intern project at Cisco to help in the visualization of mediatrace data. Mediascope uses the IOS Web Services Management Agent (WSMA) interface to execute mediatrace commands. As a flash based tool, mediascope can be hosted on a regular web server in your network and be available for general users (well except for ipad/iphone!).

The user initially logs into the mediascope tool with a mediascope specific password. Then the target router is identified and credentials for that node are provided. At this point, the user can ask mediascope to dynamically configure IOS performance monitor to discover the flows traversing the target router. The discovered flows are dynamically displayed in a list allowing the user to select the interesting flow and then continue on to the specific metrics to be gathered (lower part of Figure 1 below).

Figure 1. Mediascope Flow selection and Data Retrieval Selection

Figure 2. Mediascope Result Visualization

In Figure 2, we can see the result of the mediatrace run. Note from Figure 1 that the y-axis in the chart is selectable, as are the meanings of the color. In our example, the height of the circles conveys number of IP packets seen for the monitored flow, size conveys CPU utilization, and conditional coloring based on number of packets lost and jitter values. Of course, a much simpler chart could be constructed, but we wanted to show how easily very dense information could be represented.

Using the chart the operator is able to quickly identify the node that is at high CPI, but also the node that seems to be seeing packet loss.

We had a lot of fun creating mediascope. Check out our multi-language demos on YouTube!  We invite you to make your own audio version- with the challenge of no English words at all. I’m hoping we’ll see one in Klingon soon!

Mediascope demo: English German Spanish

Mediascope is open sourced under the BSD license.

http://medianet.sourceforge.net/

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Mediatrace: A Better Traceroute that Does the Walking for You

March 17, 2011 at 2:30 pm PST

The classic traceroute tool has become an essential tool for network engineers. Traceroute is able to discover layer-3 nodes (routers) along the path towards a destination. This information provides operators with visibility about the path towards a destination.

However, there are limitations to traceroute such as issues with traceroute following the right path (as it’s IP source address might be different), no layer-2 (switches and bridges) discovery and really only a single piece of information is returned (IP address of the router).

With mediatrace, which shares the IP header of the flow you would like to trace, you can have much better path congruency—and confidence in the discovery. The mediatrace will also not only discover the routers (as with traceroute), but also switches that are only doing layer 2 forwarding.

Mediatrace does not need to be enabled on every hop. If it is not enabled on node, the mediatrace packet will simply be forwarded through that part of the network. This is exactly what would happen in the case of your traditional MPLS-VPN network.

Figure 1. Mediatrace tracing a flow while the operator chillaxes

Now for the best part! Mediatrace can dynamically engage the performance monitor feature we talked about a few weeks ago. This allows a dynamic surgical monitoring policy to be applied for the flow we are tracing that results in hop by hop performance measurements such as loss and jitter. As is the case with all mediatrace runs, the information is brought back into a single report where it can be quickly analyzed.

Figure 2. Mediatrace integration with performance monitor

Despite the name, mediatrace is not only for voice/video flows. It is able to trace any IP flow, and is even able to engage performance monitor to gather hop by hop TCP stats.

Mediatrace is a new tool that cisco released in IOS 15.1(3)T  for the ISR platforms as part of the medianet program.  Over the course of 2011, this feature will proliferate across cisco’s enterprise line of routers and switches.

Mediatrace Configuration Guide
http://www.cisco.com/en/US/docs/ios/media_monitoring/configuration/guide/mm_mediatrace.html

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IOS Performance Monitor – A powerful tool for negotiating SLA with your Service Provider

The only way to be sure of delivering highest quality of experience is by actually measuring QoE of real traffic. In IOS 15.1.3T, we introduced a new embedded monitoring capability to collect packet loss, jitter, delay and response time information for performance evaluation of data, voice and video services. The feature is called IOS Performance Monitor.  (See yesterday’s blog on User Traffic Analysis by Medianet performance Monitor.)   

In December of last year, Cisco IT was running a medianet pilot program for the new IOS performance monitor feature as their ongoing effort to provide high quality and improved services to end users. The pilot was designed to support 50 remote sites equipped with the ISR-891 routers. Two of the pilot sites were small Cisco offices and the remaining was home offices. I was lucky enough to be selected for the pilot.

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User Traffic Analysis by Medianet Performance Monitor

February 28, 2011 at 5:06 pm PST

Network operators are tasked with providing a foundation network that can deliver a variety of applications to their users at any time. For the most part, the network is in the background, humming away while users enjoy the applications. However; once in a while, the application will slow down, or hiccup, and the first suspect is usually the network.

Figure 1 - Poor video quality caused by packet loss.

Sometimes this is not without just cause; the network may be composed of various administrative domains in various states of work, and many things that are outside the domain of control of any network operator (bad fiber, rain clouds, bulldozers, floods etc.). There is the common experience of the ping test passing, but still something wrong within the network. Or the other case, where the ping fails intermittently, but there is no clue about the location of the problem.

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