On Thu, Feb 24, 2011 at 6:10 PM, Diogo Montagner <diogo.montagner@gmail.com> wrote:
Hello,
I am looking for industry standard parameters to base the SLA of one network regarding to voice, video and data application.
One won't find many, but a common rule of thumb is most apps will be 'fine' with networks that provide 10E-6 BER or lower loss rates.
Which are the the accepted values for jiiter, delay, latency and packet loss for voice, video and data in a IP/MPLS ?
This question is being framed backwards -- an engineer should ask ask what the particular codecs can tollerate, then seek out networks which can deliver on those needs. If the a/v equipment vendor can't tell the customer or user what sort of network is required, I recommend selecting a new a/v vendor. In any event, audio codecs such as ILBC, g729, and 722 are well positioned for 'loss concealment' mechanisms in the decoders, masking some reasonable amount of loss. This has been exhaustively tested, and the data is readily available [0]. Video codecs that degrade gracefully are also fairly common, though the industry focus seems to be on concealing loss for generic real-time data, and offloading this work onto a different abstraction. One example would be packetized 'forward error correction' schemes, which can be configured or adapted to nearly arbitrarily 'high' loss rates (eg. "ProMPEG" [1] and related work). If the a/v system in question can support FEC of any sort, then this should substantially reduce ones transport-layer loss rate concerns. -Tk [0]: http://www.vocal.com/speech_coders/psqm_data.html [1]: http://www.ispa-sat.ru/info/Inside%20Pro-MPEG%20FEC%20(IBC)%20.pdf