IP SLA not working

[benson.low]

Hi CSC,

I have tried to implement IP SLA to monitor udp-jitter for voice packets, but it was not successful.

Configuration on R1

R1#show run | sec ip sla

ip sla 1

udp-jitter x.x.x.8 5000

ip sla schedule 1 life forever start-time now

ip sla 2

udp-jitter x.x.x.8 16384 codec g711alaw

ip sla schedule 2 life forever start-time now

SLA 1

Type of operation: udp-jitter

        Latest RTT: 39 milliseconds

Latest operation start time: 12:17:56 SIN Thu May 17 2012

Latest operation return code: OK

RTT Values:

        Number Of RTT: 10               RTT Min/Avg/Max: 38/39/40 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: 9

        Number of DS Jitter Samples: 9

        Source to Destination Jitter Min/Avg/Max: 0/1/1 milliseconds

        Destination to Source Jitter Min/Avg/Max: 0/1/1 milliseconds

Packet Loss Values:

        Loss Source to Destination: 0

        Source to Destination Loss Periods Number: 0

        Source to Destination Loss Period Length Min/Max: 0/0

        Source to Destination Inter Loss Period Length Min/Max: 0/0

        Loss Destination to Source: 0

        Destination to Source Loss Periods Number: 0

        Destination to Source Loss Period Length Min/Max: 0/0

        Destination to Source Inter Loss Period Length Min/Max: 0/0

        Out Of Sequence: 0      Tail Drop: 0

        Packet Late Arrival: 0  Packet Skipped: 0

Voice Score Values:

        Calculated Planning Impairment Factor (ICPIF): 0

        Mean Opinion Score (MOS): 0

Number of successes: 5

Number of failures: 0

Operation time to live: Forever

SLA 2

IPSLA operation id: 2

Type of operation: udp-jitter

        Latest RTT: NoConnection/Busy/Timeout

Latest operation start time: 12:19:46 SIN Thu May 17 2012

Latest operation return code: Timeout

RTT Values:

        Number Of RTT: 0                RTT Min/Avg/Max: 0/0/0 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: 0

        Number of DS Jitter Samples: 0

        Source to Destination Jitter Min/Avg/Max: 0/0/0 milliseconds

        Destination to Source Jitter Min/Avg/Max: 0/0/0 milliseconds

Packet Loss Values:

        Loss Source to Destination: 0

        Source to Destination Loss Periods Number: 0

        Source to Destination Loss Period Length Min/Max: 0/0

        Source to Destination Inter Loss Period Length Min/Max: 0/0

        Loss Destination to Source: 0

        Destination to Source Loss Periods Number: 0

        Destination to Source Loss Period Length Min/Max: 0/0

        Destination to Source Inter Loss Period Length Min/Max: 0/0

        Out Of Sequence: 0      Tail Drop: 0

        Packet Late Arrival: 0  Packet Skipped: 0

Voice Score Values:

        Calculated Planning Impairment Factor (ICPIF): 0

        Mean Opinion Score (MOS): 0

Number of successes: 0

Number of failures: 16

Operation time to live: Forever

R2#show ip sla responder

        General IP SLA Responder on Control port 1967

General IP SLA Responder is: Enabled

Number of control message received: 18 Number of errors: 0

Recent sources:

        x.x.x.8 [12:21:46.819 SIN Thu May 17 2012]

        x.x.x.8 [12:20:46.809 SIN Thu May 17 2012]

        x.x.x.8 [12:19:46.803 SIN Thu May 17 2012]

        x.x.x.8 [12:18:46.797 SIN Thu May 17 2012]

        x.x.x.8 [12:17:46.792 SIN Thu May 17 2012]

Recent error sources:

        Permanent Port IP SLA Responder

Permanent Port IP SLA Responder is: Enabled

udpEcho Responder:

  IP Address             Port

  x.x.x.x.8          16384

  x.x.x.x.8           5000

I have setup ip sla responder on R2, but it does not work. Any advice is appreciated. Thanks.

[smehrnia]

Hi,

Try adding a frequency (second) under ur sla operation and run NTP on your SLA source and responder, because for UDP jitter to work properly time sync is important between src n rspnder.

if all those didnt help, try this form of sla command:

ip sla monitor 1

  type jitter dest-ipadd x.x.x.x dest-port xxxx

  frequency 10

!

ip sla monitor schedule 1 start-time now life forever

!

!

PLZ Rate if it helped.

Soroush.

[benson.low]

Hi Soroush,

Thanks for the tips, i forget to mention that both routers are in sync with the same time server. I have tweak the frequency to 300 and I have already configured suggested jitter, and it is running fine for the suggested jitter, but not for the udp-jitter for voice traffic, but i am more concern on voip traffic and wish to get the statistics from voice score values:

My ios version is

Version 15.1(4)M3, RELEASE SOFTWARE (fc1)

A quick check reveals that it is capable of doing the required ops, but i may be wrong.

[smehrnia]

that is exactly what you need to work. " jitter " is actualy same thing as UDP jitter and as far as i know that's what u need for voice. unless u explicitly state otherwise; like icmp-jitter.

> check this cisco doc on udp jitter:

http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6555/ps6602/prod_white_paper0900aecd804fb392.pdf

PLZ Rate if it helped.

Soroush.

[benson.low]

Hi Soroush,

Thanks, managed to find out the issue, i need to change my udp port. Guess that it might be in used. Take a look at voice score, it shows meaningful data now, whereas udp-jitter would not give such information.

vg1.sg0#show ip sla statistics 1

IPSLAs Latest Operation Statistics

IPSLA operation id: 1

Type of operation: udp-jitter

        Latest RTT: 40 milliseconds

Latest operation start time: 15:45:24 SIN Thu May 17 2012

Latest operation return code: OK

RTT Values:

        Number Of RTT: 999              RTT Min/Avg/Max: 39/40/54 milliseconds

Latency one-way time:

        Number of Latency one-way Samples: 999

        Source to Destination Latency one way Min/Avg/Max: 1/1/7 milliseconds

        Destination to Source Latency one way Min/Avg/Max: 37/38/47 milliseconds

Jitter Time:

        Number of SD Jitter Samples: 997

        Number of DS Jitter Samples: 998

        Source to Destination Jitter Min/Avg/Max: 0/1/5 milliseconds

        Destination to Source Jitter Min/Avg/Max: 0/1/9 milliseconds

Packet Loss Values:

        Loss Source to Destination: 1

        Source to Destination Loss Periods Number: 17

        Source to Destination Loss Period Length Min/Max: 1/32

        Source to Destination Inter Loss Period Length Min/Max: 6/32

        Loss Destination to Source: 0

        Destination to Source Loss Periods Number: 0

        Destination to Source Loss Period Length Min/Max: 0/0

        Destination to Source Inter Loss Period Length Min/Max: 0/0

        Out Of Sequence: 0      Tail Drop: 0

        Packet Late Arrival: 0  Packet Skipped: 0

Voice Score Values:

        Calculated Planning Impairment Factor (ICPIF): 1

        MOS score: 4.34

Number of successes: 2

Number of failures: 0

Operation time to live: Forever

Rgrds,

Benson