Network Monitoring – Measuring Per-Link Latency, Jitter, and Packet Loss

latencymonitoringpacket-lossrouterswitch

I need to measure the latency, jitter and packet-loss per link in a network, as opposed to end-to-end, e.g. like this:

s1-eth0 <–> s2-eth0 (~ 20µs avg. latency, standard derivation 10µs, 57 % packet loss /last sec)

s2-eth1 <–> s3-eth0 (~ 25µs avg. latency, standard derivation 5µs, 21 % packet loss / last sec)

…

All solutions i was able to find were either academic proposals or involve using dedicated hardware for active probing.

Here is a summary what according to my research does no work out:

  • NetFlow: No latency information, only end-to-end
  • Active Probing: It's Not possible for me to change the configuration of the network
  • Measure Roundtrip-Time: does not provide per-link-statistics

Is there any network protocol, measurement tool or other functionality providing all or at least some of the above statistics?

Best Answer

On Cisco devices, you can use Cisco IP SLA. You need to first configure and enable it, and then monitor the results.

Steps:

1. ip sla monitor operation-number

2. type echo protocol ipIcmpEcho {destination-ip-address | destination-hostname} [source-ipaddr {ip-address | hostname} | source-interface interface-name]

3. frequency seconds

4. ip sla monitor schedule operation-number [life {forever | seconds}] [start-time {hh:mm[:ss] [month day | day month] | pending | now | after hh:mm:ss] [ageout seconds] [recurring]

Configuration example took from Cisco: IP SLAs--Analyzing IP Service Levels Using the ICMP Echo Operation.

Router> enable
Router# configure terminal
Router(config)# ip sla monitor 10
Router(config-sla-monitor)# type echo protocol ipIcmpEcho 172.29.139.134
Router(config-sla-monitor-echo)# frequency 300
Router(config-sla-monitor-echo)# exit
Router(config)# ip sla monitor schedule 10 start-time now life forever

To monitor:

show ip sla monitor statistics
Related Topic