TelePresence Server packet loss

[Justin Pascal]

In TelePresence world, with the use of RTCP/MUX via MUX echo type packet we can detect packet loss and drop calls in Endpoint if packet loss exist > 10% in some specific continuos time, if we have other type of endpoints (Movi, Polycom, Lifesize, MS, etc) connecting to a Telepresence server, but this endpoints are not TIP capable (CTS,TX, etc)

Questions:

a) Whats the behavior in TPS after detecting packet loss (not recieving media) from EP.

I saw packet loss threshold.

http://www.cisco.com/en/US/docs/telepresence/infrastructure/articles/ts_diagnose_packet_loss_kb_444.shtml

But its only for reporting.

b) Does TP will send a black/frozen screen to other meeting participants?

c) Is there an option to drop EP if packet loss threshold exceeds?

Thanks

- JP

[crisalex]

Hi Justin,

I can give a try to answer :

As per the product specification  the TPS has the following netwrok resiliency mechanisms :

•  Cisco TelePresence PacketSafe technology, which provides intelligent  down speeding, packet pacing, and packet-loss concealment to ensure  optimum video and audio quality

• Dynamic jitter buffering

The TPS has also enabled by default 1 optimization mechanims if  corrupted packets are received  :

Received video: flow control on video errors (

llows the TelePresence Server  to request that the endpoint or endpoint group send lower speed video  if it fails to receive all the packets which comprise the far end's  video stream )

As per the online help :

"

The TelePresence Server  can send these messages to endpoints requesting that the bandwidth of  the video that they are sending be decreased based on the quality of  video received by the TelePresence Server.

If there is a bandwidth limitation in the path between the endpoint/endpoint group and the TelePresence Server, it is better for the TelePresence Server to receive every packet of a lower rate stream than to miss some packets of a higher rate stream.

"

Regards