Friday, April 1, 2022

Configure IP SLA udp-jitter in a Cisco ASR1K

Here's a nice link regarding IP SLA in a Cisco router. I needed to configure a udp-jitter probe between two ASR1K routers to monitor its path latency, jitter and packet loss. I just need to configure ip sla responder on ASR2 and the rest of the IP SLA config would be on ASR1

 

ASR2#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

ASR2(config)#ip sla responder

ASR2(config)#end

ASR2#write memory

Building configuration...

[OK]

 

 

ASR2#show run | section ip sla

ip sla responder

 

 

-----

 

 

ASR1#configure terminal

Enter configuration commands, one per line.  End with CNTL/Z.

ASR1(config)#ip sla 100

ASR1(config-ip-sla)# udp-jitter 10.1.1.8 16384 source-ip 10.1.1.7 codec g729a

ASR1(config-ip-sla-jitter)# tos 184

ASR1(config-ip-sla-jitter)# frequency 30

ASR1(config-ip-sla-jitter)# owner ASR1 > ASR2 TUNNEL

ASR1(config-ip-sla-jitter)#

ASR1(config-ip-sla-jitter)#ip sla schedule 100 life forever start-time now

ASR1(config)#end

 

ASR1#show run | sec ip sla 100

ip sla 100

 udp-jitter 10.1.1.8 16384 source-ip 10.1.1.7 codec g729a

 tos 184

 owner ASR1 > ASR2 TUNNEL

 frequency 30

 

ASR1#write memory

Building configuration...

[OK]

 

ASR1#show run | sec ip sla 100

ip sla 100

  udp-jitter 10.1.1.8 16384 source-ip 10.1.1.7 codec g729a

 tos 184

 owner ASR1 > ASR2 TUNNEL

 frequency 30

 

 

Just allow a few minutes for the IP SLA probe to run and collect statistics. You can also add monitoring/graph in an NMS for viewing historical data.

 

ASR1#show ip sla statistics 100 details

IPSLAs Latest Operation Statistics

 

IPSLA operation id: 100

Type of operation: udp-jitter

        Latest RTT: 19 milliseconds

Latest operation start time: 12:56:08 UTC Thu Mar 17 2022

Latest operation return code: OK

Over thresholds occurred: FALSE

RTT Values:

        Number Of RTT: 999              RTT Min/Avg/Max: 17/19/29 milliseconds

Latency one-way time:

        Number of Latency one-way Samples: 999

        Source to Destination Latency one way Min/Avg/Max: 9/10/19 milliseconds

        Destination to Source Latency one way Min/Avg/Max: 8/9/18 milliseconds

        Source to Destination Latency one way Sum/Sum2: 10565/113077

        Destination to Source Latency one way Sum/Sum2: 9150/84308

Jitter Time:

        Number of SD Jitter Samples: 997

        Number of DS Jitter Samples: 998

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

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

        Source to destination positive jitter Min/Avg/Max: 1/1/9 milliseconds

        Source to destination positive jitter Number/Sum/Sum2: 286/475/1329

        Source to destination negative jitter Min/Avg/Max: 1/1/9 milliseconds

        Source to destination negative jitter Number/Sum/Sum2: 293/478/1288

        Destination to Source positive jitter Min/Avg/Max: 1/1/7 milliseconds

        Destination to Source positive jitter Number/Sum/Sum2: 180/229/425

        Destination to Source negative jitter Min/Avg/Max: 1/1/9 milliseconds

        Destination to Source negative jitter Number/Sum/Sum2: 181/230/468

        Interarrival jitterout: 0       Interarrival jitterin: 0

        Jitter AVG: 1

Over Threshold:

        Number Of RTT Over Threshold: 0 (0%)

Packet Loss Values:

        Loss Source to Destination: 1

        Source to Destination Loss Periods Number: 1

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

        Source to Destination Inter Loss Period Length Min/Max: 205/794

        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): 11

        MOS score: 4.06

Number of successes: 6

Number of failures: 0

Operation time to live: Forever

Operational state of entry: Active

Last time this entry was reset: Never


Below are the graphs for network latency, jitter and packet loss taken from NMS.