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I'm sure many of them have done interesting things.

But the area I write software on in broadcast has a large number of these engineers holding back progress, most of whom are close to retirement age and now have heavy influence in standards bodies. For uncompressed video over IP for example they propose insanely tight standards such as packets must arrive within ~40us (that's us, not ms) of their allotted time, something very difficult to reach in software. (I will be talking about this at demuxed next week...)

They also insist that legacy artefacts from the analogue era must remain such as VBI stay for another generation to save around 1ms of latency (and of course their precious line buffers).

They are one reason the broadcast industry isn't able to move fast enough compared to the web. As I've explained to them, some of us will have to deal with the mess they have created in 40 years time.




> packets must arrive within ~40us (that's us, not ms) of their allotted time, something very difficult to reach in software. (I will be talking about this at demuxed next week...)

Maybe in Ethernet-land, but this is trivially achievable (actually exceeded by more than an order of magnitude) with off-the-shelf Infiniband gear that is available for peanuts these days. Actually it's close to two orders of magnitude if you want to shell out for the latest gear.

https://en.wikipedia.org/wiki/InfiniBand#Performance


Yes, easily possible with Infiniband but quite complex with Ethernet.


But does it actually provide a real-time guarantee?


Yes. Adapter latency is guaranteed to be 0.5-5 usec depending on generation (later revisions are faster+lower latency). Switches add about 170 nsec per hop, plus whatever speed-of-light delays your cables add. 1 usec end-to-end is realistic for modern gear.

http://www.hpcadvisorycouncil.com/events/2014/swiss-workshop...

Of course with IP-over-IB you also need to factor in whatever latency is added from your network stack, but Infiniband also supports RDMA so IB-aware applications can essentially bypass this for high-performance or hard-real-time usecases.

Basically, Infiniband takes the network out of the equation here. The bottleneck then becomes how precisely you can time the software.




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