Good point Steve
But now has brought up a interesting question Does IP SLA rely on all clocks being synchronized or does it analyze the time it receives a response from the responder against its own clock? --- You got me thinking..... Thoughts From: Di Bias, Steve [mailto:[email protected]] Sent: October-29-10 11:42 AM To: Jason Maynard; 'Adam Booth' Cc: [email protected] Subject: RE: [OSL | CCIE_RS] Question 160 >From a real world perspective your clocks need to be synchronized when monitoring jitter, so my solution would have included NTP and IP SLA. Even if your timestamps are off by only a few seconds your results will be skewed. Other than that Adam's solution looks good. Also the command syntax and options I see on (C3725-ADVIPSERVICESK9-M), Version 12.4(25b) differ from what I see in Adams config. R2 clock timezone PST -8 clock set 08:30:00 29 Oct 2010 ntp master 3 interface FastEthernet0/0 ip address 10.186.12.2 255.255.255.0 ip sla monitor 10 type jitter dest-ipaddr 10.186.12.1 dest-port 16384 source-ipaddr 10.186.12.2 codec g729a ip sla monitor schedule 10 life forever start-time now R2(config)#do sh clock 08:30:14.735 PST Fri Oct 29 2010 R2(config)#do sh ntp stat | in Clo Clock is synchronized, stratum 3, reference is 127.127.7.1 R1 interface FastEthernet0/0 ip address 10.186.12.2 255.255.255.0 R1(config)#ip sla mon responder R1(config)#do sh ntp stat | in Clock Clock is synchronized, stratum 4, reference is 10.186.12.2 R1(config)#do sh ntp ass address ref clock st when poll reach delay offset disp *~10.186.12.2 127.127.7.1 3 47 64 37 1.9 3.38 875.3 both clocks R1(config)#do sh clock 16:44:16.337 UTC Fri Oct 29 2010 R2(config)#do sh clock 08:44:16.383 PST Fri Oct 29 2010 R2(config)#do sh ip sla mon stat Round trip time (RTT) Index 10 Latest RTT: 2 ms Latest operation start time: 08:45:44.923 PST Fri Oct 29 2010 Latest operation return code: OK RTT Values Number Of RTT: 1000 RTT Min/Avg/Max: 1/2/3 ms Latency one-way time milliseconds Number of one-way Samples: 0 Source to Destination one way Min/Avg/Max: 0/0/0 ms Destination to Source one way Min/Avg/Max: 0/0/0 ms Jitter time milliseconds Number of SD Jitter Samples: 999 Number of DS Jitter Samples: 999 Source to Destination Jitter Min/Avg/Max: 0/1/1 ms Destination to Source Jitter Min/Avg/Max: 0/1/2 ms Packet Loss Values Loss Source to Destination: 0 Loss Destination to Source: 0 Out Of Sequence: 0 Tail Drop: 0 Packet Late Arrival: 0 Voice Score Values Calculated Planning Impairment Factor (ICPIF): 11 MOS score: 4.06 Number of successes: 8 Number of failures: 3 Operation time to live: Forever Thank you, Steve Di Bias Network Engineer - Information Systems Valley Health System - Las Vegas Office - 702- 369-7594 Cell - 702-241-1801 <mailto:[email protected]> [email protected] _____ From: [email protected] [mailto:[email protected]] On Behalf Of Jason Maynard Sent: Friday, October 29, 2010 5:09 AM To: 'Adam Booth' Cc: [email protected] Subject: Re: [OSL | CCIE_RS] Question 160 Hey Adam, Looks good I wanted to keep it vague to show that all that really matters is what is in front of you and in this case it is "Monitor" and "Jitter" between devices. I struggled in the past with not having all (what I believe is all) the requirements but learned that all I needed to do was meet the requirement. Some things that were left up to you were type, codec, ports, etc. I believe "ip sla" is only on legacy IOS's and the newer IOS's use "ip sla monitor" - Please correct me if I am wrong I would like to how others put their solutions together Thanks Adam! From: Adam Booth [mailto:[email protected]] Sent: October-29-10 12:34 AM To: Jason Maynard Cc: [email protected] Subject: Re: [OSL | CCIE_RS] Question 160 Hi Jason, There's a number of jitter measurement options available using ip sla, I took the assumption that since your picture had IP phones, that udp jitter simulating a voip call may be appropriate. Below are my proposed configs. hostname R1 ! interface FastEthernet0/0 ip address 10.0.0.1 255.255.255.0 no shutdown ! ip sla 10 udp-jitter 10.0.0.2 16384 codec g729a ip sla schedule 10 life forever start-time now hostname R2 ! interface FastEthernet0/0 ip address 10.0.0.2 255.255.255.0 no shutdown ! ip sla responder R1#sh ip sla stati 10 Round Trip Time (RTT) for Index 10 Latest RTT: 22 milliseconds Latest operation start time: *00:14:19.003 UTC Fri Mar 1 2002 Latest operation return code: OK RTT Values: Number Of RTT: 1000 RTT Min/Avg/Max: 1/22/493 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: 999 Number of DS Jitter Samples: 999 Source to Destination Jitter Min/Avg/Max: 0/17/67 milliseconds Destination to Source Jitter Min/Avg/Max: 0/7/496 milliseconds Packet Loss Values: Loss Source to Destination: 0 Loss Destination to Source: 0 Out Of Sequence: 0 Tail Drop: 0 Packet Late Arrival: 0 Packet Skipped: 0 Voice Score Values: Calculated Planning Impairment Factor (ICPIF): 4209067962 MOS score: 4.50 Number of successes: 1 Number of failures: 0 Operation time to live: Forever It is possible to reflect the configuration for R1 and R2 but since we get both Source to Destination and Destination to Source jitter this way, it's probably not required. Cheers, Adam On Fri, Oct 29, 2010 at 1:30 PM, Jason Maynard <[email protected]> wrote: Here is another question to test your skills. What would you configure to monitor jitter? You must provide an example using R1 and R2. <http://4.bp.blogspot.com/_RcSjgG49QBc/TMo8YRb73lI/AAAAAAAAAEY/SD-bnXKSdXM/s 1600/Phone.png> Error! Filename not specified. Error! Filename not specified. Error! Filename not specified. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com UHS Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this information is prohibited, and may be punishable by law. If this was sent to you in error, please notify the sender by reply e-mail and destroy all copies of the original message.
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