show IP SLA statistics output definitions

[alexneishell]

Does anyone have a link or documentation that defines ALL the fields in a show ip sla statistics command? Some are clearly obvious, but in Packet Loss Values for instance what are the measurement values for Source to Destination Loss Periods Number: or Source to Destination Loss Periods Number: ?

IPSLA operation id: 8502
Start Time Index: 13:56:14 UTC Tue Mar 25 2014
Type of operation: udp-jitter
Voice Scores:
        MinOfICPIF: 0   MaxOfICPIF: 0   MinOfMOS: 0     MaxOfMOS: 0
RTT Values:
        Number Of RTT: 48157            RTT Min/Avg/Max: 54/56/503 milliseconds
Latency one-way time:
        Number of Latency one-way Samples: 0
        Source to Destination Latency one way Min/Avg/Max: 0/0/0 milliseconds
        Destination to Source Latency one way Min/Avg/Max: 0/0/0 milliseconds
Jitter Time:
        Number of SD Jitter Samples: 43824
        Number of DS Jitter Samples: 43824
        Source to Destination Jitter Min/Avg/Max: 0/1/142 milliseconds
        Destination to Source Jitter Min/Avg/Max: 0/1/81 milliseconds
Packet Loss Values:
        Loss Source to Destination: 96 
        Source to Destination Loss Periods Number: 796 
        Source to Destination Loss Period Length Min/Max: 1/17
        Source to Destination Inter Loss Period Length Min/Max: 1/2828
        Loss Destination to Source: 5746 
        Destination to Source Loss Periods Number: 4319
        Destination to Source Loss Period Length Min/Max: 1/17
        Destination to Source Inter Loss Period Length Min/Max: 1/321
        Out Of Sequence: 0      Tail Drop: 1
        Packet Late Arrival: 0  Packet Skipped: 0
Number of successes: 18
Number of failures: 30

[Vinod Arya]

Hopefully all the information will be available in this document which is one of the best to understand different kind of operations and how values are calculated.

A litlle in depth and would need some considerable time to go through :

http://www.cisco.com/en/US/technologies/tk648/tk362/tk920/technologies_white_paper09186a00802d5efe.html

Hope it will be helpful.

-Thanks

Vinod

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[alexneishell]

thanks Vinod. I have this document, and it is close, but does not provide the detial that I am looking for. Appreciate it though.

[Vinod Arya]

I was hoping you would have this document as it is one of the most famous of all. I have one more document link, which explaing UDP jitter and how its values are calculated. Please check and let me know if it is useful in what you're looking for :

http://docwiki.cisco.com/wiki/IOS_IP_SLAs_UDP_Jitter_Operation_Technical_Analysis

-Thanks

Vinod

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[alexneishell]

this is a great document as well, but doesn't dive down deep enough. The best example would be Packet Loss, where is says -

Packet Loss

Five types of packet loss or assimilated events can be measured with IP SLA:

• Packet loss in the source to destination (packetLossSD)
• Packet loss in the destination source (packetLossDS)
• Tail Drop: we know it has been dropped, but we do not know in which direction. This is when the last packet(s) of the test streams were dropped, because in this case, we do not receive the sequence numbers. In older releases, this is called Packet MIA for missing in action. In the MIB, the notation PacketMIA is still in use.
• Packet Late Arrival: the packet did arrive, but so late that the underlying application probably considered it as dropped, or at least not useful. Think about a VoIP application. If one packet arrives much later than expected, it is too late because the conversation keeps going. This packet is assimilated to a drop.
• Packet Misordering: the packet arrived but not in the right order. This may or may not be considered as a packet drop. (packetOutOfOrder)

The cool thing is the power that lies behind those numbers. Differenct values can be calculated the way you want it. For instance the total amount of packet dropped is:

packetDropped = RTTMonPacketLossSD + RTTMonPacketLossDS + RTTMonPacketMIA

The total percentage of packets that have dropped during the instance is:

drop_rate_%age = 100 * packetDropped / (RTTMonNumOfRTT + packetDropped)

Many other values can be calculated, and that is entirely up to you to decide what parameters are important.

But does not address the fields that I am looking for -

Source to Destination Loss Period Length Min/Max: 1/17
        Source to Destination Inter Loss Period Length Min/Max: 1/2828
       
        Destination to Source Loss Periods Number: 4319
        Destination to Source Loss Period Length Min/Max: 1/17
        Destination to Source Inter Loss Period Length Min/Max: 1/321

appreciate all the input though Vinod!

[rwharris13]

Alex - I'm looking for the same exact info, those specific outputs don't seem to be explained in any document I've found. I opened a TAC case on it as well so I will update if I get an answer.
 

[alexneishell]

This is what I've gotten from my TAC case

In general, the "Loss Period Length" is the number of consecutive packet lost (sub-divided into source to destination and viceversa).

The "Inter Loss Period Length" is the number of packets in between two Loss Periods, i.e. the number of consecutive packets successfully received in a row.

In your case, you had 2828 packets in a row received back at the sender, and a worst case of a burst of 17 packets lost in a row.

The "Number" is a cumulative sum updated at every probe iteration.

Still, it'd be nice to have a reference for all the fields.

[bpeng0001]

Hi Alex,

I saw some of your post and I am having similar problems as yours. I don't know how to reach out to you, so I choose to post my question here. My apology in advance if this violates any regulation.

I am very new to the IP SLA. My project requires me to config udp-jitter operations across different routers at the lab.

My config looks like below:

ip sla 201

udp-jitter 10.1.1.1 5201 source-ip 10.1.1.2

frequency 30

exit

ip sla schedule 201 start-time now life forever.

My questions are:

a) This config worked from router A to router B. However, similar config doesn't work from router B to router A and I am seeing the " no connection " error. I am certainly sure that I enabled ip sla responders on both sides. Any ideas?

b) The RTT values are always 1ms. I doubt it is accurate. And I am not receiving any values for per-direction jitter, or latency, etc. Is there anything to be done? However, I used Cacti to pull the jitter values, and strangely I would be able to have some variance ( not zero as shown in ip sla statistics).

I don't find the Cisco documents very specificly helpful, and hopefully someone can give me some advice.

Thanks a lot

[alexneishell]

not sure about the no connection issue, but there is a bug in the IOS that some of the ISR's run, that could be the issue with seeing 1/1/1 results. I don't have the exact code versions affected in front of me, try the Bug Search tool, that will show you