We have some customers that are migrating from PRTG to Zabbix and are using ICMP jitter sensors to monitor difference between ICMP ping packets as an indication for possible issues with VOIP traffic on internet links.

As Zabbix is already using fping as an ICMP probe, I think this should be relatively easy to implement. To keep it in line with the other icmpping simplechecks, something like this would be good:

icmppingjitter[<target>,<packets>,<interval>,<size>,<timeout>,<options>,<min|max|avg>,<TOS>]

By default this should return average jitter of number of <packets>. Most of the options are the same as with the other icmpping items.

<min|max|avg> could be specified to return minimal or maximal jitter instead.
<TOS> field should be usable to set the type of service it needed, to allow for matching on network QoS policies. See "-O, --tos=N" in the fping manual for further details.

Please also see https://www.3rdechelon.net/jittercalc.asp for more background info on how to do the calculations.