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Polycom RMX 4000 - video in video out packet loss

Frequent Advisor

Polycom RMX 4000 - video in video out packet loss



Would like to understand how to toubleshoot video in /video out losses. " The media transmitted from the endpoint to the RMX (Video in)".


I have checked with the network team and all the setting on the RMX and no issue found. Customer coming from public ip we face issue. customer coming from MPLS we havent faced any issue. 


As per the Public IP service provider all is good. I am attaching the snippet of the test call with packet loss info.

Occasional Advisor

Re: Polycom RMX 4000 - video in video out packet loss

Greetings, have you had any resolve with this issue, I am experiencing the same thing. Packet loss in and out but no indications on the network end. Incorrect flag setting on the rmx?, network setting, etc? Much thanks
Message 2 of 7
Frequent Advisor

Re: Polycom RMX 4000 - video in video out packet loss

We are still facing the issue.

Message 3 of 7
Polycom Employee & Community Manager

Re: Polycom RMX 4000 - video in video out packet loss

Hello all,

It is always useful to include the currently used software version as issues experienced may already be addressed in a newer release.

This also allows yourself and others to check against current software release notes.

Has this been brought to the attention of Polycom support yet?

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 4 of 7
Occasional Contributor

Re: Polycom RMX 4000 - video in video out packet loss

Has there ever been any more movement on this issue?

We have had this ongoing for several years with our RMX2000.

Old thread but wondering if anyone has any insight into it?

Message 5 of 7
Occasional Advisor

Re: Polycom RMX 4000 - video in video out packet loss

no movement. Network side continues to see no anomolies or even packet loss. Bridge still shows extremely inconsistent packet loss numbers. Polycom Support advises this is a network issue.


If you find something out, please update this thread as I will do the same. I see this as a software issue on the bridge side.

Message 6 of 7
Polycom Employee

Re: Polycom RMX 4000 - video in video out packet loss

Don't confuse the way your network team defines packet loss and how the RMX, or any other real time protocol device for that matter, defines packet loss.


The network team is looking to see if the packets arrive at their destination. They don't care when they arrive. The RMX on the other hand expects RTP packets to arrive in a constant and consistent packet stream. Variations in the time between when a packet was sent and when it was received is called jitter. If the jitter is too high packets can be received too late to be processed. It's what I like to call "Effective Packet Loss" as opposed to actual packet loss.


Since this appears to be a problem with external participants as opposed to internal participants I concur that this is most likely a network issue. Any device between the source and the destination could be contributing to the problem.


I can offer one suggestion. The RMX supports Lost Packet Recovery (LPR). LPR works great in situations where the loss is relatively low. In cases where the loss is high the RMX can spend so much time on the recovery process that it gets behind on other tasks and it can make the problem worse. If LPR is enabled in the conference profile, try disabling it. The reverse also applies. If it is currently disabled, try enabling it. It could be that the loss is low enough for LPR to have a positive affect.



Michael K. Bromley, CVE, CCENT, WCNA, VCA-DCV
Technical Lead
Infrastructure Technical Support Center
Message 7 of 7