North American Network Operators Group|
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Re: QOS or more bandwidth
"E.B. Dreger" <email@example.com> asks: | Although I generally agree, how does one keep QoS out of the core for CBR | and jitter-sensitive applications? Magic technology called SONET. In general, applications that really need CBR/ultra-low-jitter should stay on TDM, because it's the cheapest approach. Meanwhile applications which can benefit from the statistical multiplexing gain of the imperfect Internet (with occasional bursty loss and jitter) can migrate over to cheaper IP based networks. There are probably not very many applications which really need CBR/ultra-low-jitter: most that use TDM networks today work reasonably well across today's imperfect Internet with no QoS assistance whatsoever. As to the core: if there's no queue, there's no opportunity for (work conserving) fancy queueing. Does it pay to do work non-conserving fancy queueing? Does it pay to do fancy queueing on transients? Obviously if you don't, you can't perfectly simulate a TDM-based network, and thus can only make statistical promises about bit rate and jitter. I believe that for perfection it's cheaper to maintain a real TDM network than it is to use fancy queueing and fancier signalling to avoid and manage transient congestion in an IP based one. Sean.