Analyzing Ip Service Levels By Using The Udp Jitter Operation - Cisco Catalyst 4500 Series Configuration Manual

Configuring IP SLAs Operations
To configure the IP SLAs responder on the target device (the operational target), perform this task:
Command
Step 1
configure terminal
Step 2
ip sla responder
}
udp-echo ipaddress ip-address port
port-number
Step 3
end
Step 4
show ip sla responder
Step 5
copy running-config startup-config
To disable the IP SLAs responder, enter the no ip sla responder global configuration command. This
example shows how to configure the device as a responder for the UDP jitter IP SLAs operation in the
next procedure:
Switch(config)# ip sla responder udp-echo 172.29.139.134 5000

Analyzing IP Service Levels by Using the UDP Jitter Operation

Jitter means interpacket delay variance. When multiple packets are sent consecutively 10 ms apart from
source to destination, if the network is behaving correctly, the destination should receive them 10 ms
apart. But if there are delays in the network (like queuing, arriving through alternate routes, and so on)
the arrival delay between packets might be more than or less than 10 ms with a positive jitter value
meaning that the packets arrived more than 10 ms apart. If the packets arrive 12 ms apart, positive jitter
is 2 ms; if the packets arrive 8 ms apart, negative jitter is 2 ms. For delay-sensitive networks, positive
jitter values are undesirable, and a jitter value of 0 is ideal.
In addition to monitoring jitter, the IP SLAs UDP jitter operation can be used as a multipurpose data
gathering operation. The packets IP SLAs generates carry packet sending and receiving sequence
information and sending and receiving time stamps from the source and the operational target. Based on
these, UDP jitter operations measure this data:
•
•
•
•
Because the paths for the sending and receiving of data can be different (asymmetric), you can use the
per-direction data to more readily identify where congestion or other problems are occurring in the
network.
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
66-8
Purpose
Enters global configuration mode.
{ |
Configures the switch as an IP SLAs responder.
tcp-connect
The keywords have these meanings:
•
•
•
•
Note
Returns to privileged EXEC mode.
Verifies the IP SLAs responder configuration on the device.
(Optional) Saves your entries in the configuration file.
Per-direction jitter (source to destination and destination to source)
Per-direction packet-loss
Per-direction delay (one-way delay)
Round-trip delay (average round-trip time)
Chapter 66
tcp-connect—Enable the responder for TCP connect operations.
udp-echo—Enable the responder for User Datagram Protocol (UDP)
echo or jitter operations.
ipaddress ip-address—Enter the destination IP address.
port port-number—Enter the destination port number.
The IP address and port number must match those configured on
the source device for the IP SLAs operation.
Configuring Cisco IOS IP SLA Operations
OL-25340-01