Voice and Video Loss

[Anonymous]

I was hoping somebody could tell me where the Packet Loss would take place that is shown on the statistics screen during a video conference? We are completing a video conference between two locations over an MPLS network.  I have visibitly into every device on both sides of the MPLS network.  We are seeing packet loss during a call.  I checked every device interface for packet loss during the call, except for the MPLS network.  I open a ticket with the MPLS SP, and they are not seeing packet loss either. I have attached a screenshot which shows 17% packet loss. I see issues with all four statistics dropping packets, but ususally a higher percentage on video tx or rx than on audio.  Any help would be greatly appreciated. 

[Anonymous]

Someone needs to check the queues in the MPLS connections.  If the QOS is not set correctly, the queues could be overdriven and traffic throttled causing packet loss.

[Anonymous]

I looked at MPLS connections and the queue size is 0. I have not been able to find the cause of packet loss on any of my network equipment. Are you suggesting on the SP side?

Thanks,

Alex

[Anonymous]

Yes, the MPLS Service Provider needs to be involved as the QOS settings may be the culprit  and they may be dropping the packets.

[Polycom_Video_E]

Videoconferencing uses UDP packets so there is no retransmission of packets.  There is a jitter buffer in a videoconferencing endpoint that buffers and attempts to put them in order as they arrive before handing them off to the processors.  If a packet arrives out of order and out of the jitter buffer time it will be considered 'lost' since it was not there in time.  QoS generally helps jitter.