IP SLA VoIP Jitter ... what port?

Question

I'm trying to write an SLA test for VoiP jitter, but the default port of 17000 isn't working for me.  I don't think the traffic is being blocked (the VoIP router is the edge device on the network and its access list isn't showing matches on the block rule).  How can I tell what port to monitor for the UDP jitter?

Thanks in advance!

--JonathanP

j.otsap · Answer

I think you also need NTP synchronized between both source and target, else your results will be inaccurate (In fact I think all values other than RTT will show up as 0)

JonathanP · Answer

I'll contact my VoiP service provider and talk to them about this.  Thanks!

--JonathanP

tom.rybka · Answer

(VoIP) UDP Jitter operations need an IPSLA responder enabled on the target node, i.e. it needs to be a Cisco device with an IPSLA reponder capability and it needs to be enabled. If the target is an IPSLA node, IPSLA Manager configures the responder automatically. In case of an external target, it cannot do that since it doesn't have any credentials to access the router. Thus, you should make sure manually that the responder is enabled.

If the IPSLA responder is enabled on the target, there may be the other possible problem. The control communication with the IPSLA reponder goes through port 1967 (in addition to the port specified for probes themselves), thus please make sure that it is not blocked between a source and a target as well.