Do you have any network statistics? Having mutliple calls puts load on the TPS which could cause
jitter but sure it also puts load on the network towards the TPS.
Hi,
first of all I would like to underline that abnormal jitter values are present only when an internet endpoint is involved. TPS is inside a Data Center architecture, so internet calls or intranet calls converges in the same Data Center network.
Abnormal jitter values are reported only on CTSs logs: TPS call stats are good.
Anyway yes, we took several network statistics via IP SLA: we measured jitter in all network portions we could. The results were quietly good.
Network is configured with QoS, and devices are all Cisco 7600/6500 inside Data Center. All network stats are good (ports and so on).
Do you only see this in the statistics or do your users complain?
600ms jitter should be clearly noticable :-)
Of course video quality is really really bad. All QoS parameters (latency, packet loss) are good: so jitter is the cause of problems.
* can you pinpoint it to a specific scenario, like if a specific endpoint,, endpoint type/software version, bandwidth usage is in the jitter starts
As I told, high jitter values arise when an internet endpoint calls TPS inside Data Center. If only intranet CTSs are connected, jitter is good.
Of course an internet call has worst QoS values compared with an intranet call. But it seems like a single call point to point vith high jitter values from and internet endpoint to TPS affects also all the other calls from intranet CTSs to TPS, "sharing" the jitter with all the endpoints (CTSs and others) connected to TPS. I wonder if this is a normal behaviour or not.
* try to do a (wireshark) trace, is it the TPS "generating" the jitter or is it your network
How can I misure jitter with wireshark? I've never used it for QoS monitoring. Anyway, as I told, I'd exclude network.
What kind of software versions do you use? (endpoints and infrastructure).
Internet endpoints are miscellaneus: from ipads to samsung tablets, from radvision VC240 to Cisco EX90, so is really difficoult to collect all software versions. Anyway, it doesn't matter wich endpoint is... all internet endpoints introduces the same jitter.
VCS-C/E are 7.2, and CTS are 1.6(4). Intranet endpoints are CTSs.
what type of external endpoints are used, how are they connected (like vcs-e, traversal calls/interworking/...)
Internet endpoints with public IP address are really heterogeneous, and connect or in SIP direct access to a VCS-E (to port UDP/TCP 5060), or via Traversal zone between two VCS-E (one vcs-e customer, one vcs-e provider).
Does it make a difference if you run the latest software?
No, we tried TPS 2.2, 2.3 and 3.0 (our target release is 2.3).
Thanks to everyone.
Regards
