
Getting started with software-defined networking - jhibbets
https://www.redhat.com/sysadmin/getting-started-sdn
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lostmsu
I did not learn anything useful from this article, as it gives no concrete
examples.

Set a goal, optionally explain the need for it, pick one technology from the
list, and show how to achieve that goal.

Would be also good to show how is this different from traditional networking.

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superbaconman
We need more software engineers in this space (and not just at the edge). The
way some of these core networks are maintained just makes me shake my head.
There are way too many manual processes and way too much push back whenever
software is introduced to standardize configs.

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hideo
That's an interesting point. What companies are in this space? VMWare
recruiters mentioned (to me) a big SDN investment ~6ish years ago but I
haven't heard much after that.

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kvm000
The company I work for is in the SDN space but specifically around large scale
uncompressed (SMPTE 2110, 1.5Gbps per HD stream) video broadcast IP
infrastructure rather than related to docker containerization.

We've been deploying larger and larger systems based around our hardware IP
switch fabrics (EXE/IPX) and using our SDN controller
([https://evertz.com/solutions/magnum](https://evertz.com/solutions/magnum))
to manage network topology for systems over 150,000 multicast flows with
television broadcast critical timing/latency on stream switching.

We're hiring!
[https://evertz.com/about/careers/](https://evertz.com/about/careers/)

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kingosticks
Sorry if this is a dumb question but what does

> with television broadcast critical timing/latency on stream switching.

mean? Is this minimising the time it takes for the channel to change once the
person sitting at home has clicked the remote? Or is this for live
broadcasters trying to mux multiple raw video streams into a single watchable
stream? Or something else?

If the former, what's special about that case over some normal network box?

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kvm000
The type of system I was referring to is the core within the broadcast
facility, rather than extending to the home viewers (which is a separate
downstream distribution encoding/mux process). Timing is important for when
you switch between different video feeds to avoid on-air impacts so all the
signals have to be video frame-aligned basically. In an IP system PTP timing
is used to lock all the devices since greater precision is needed than NTP can
provide.

Low-latency is also important for when the SDN system initiates a route to
switch since it generally needs to happen according to a tight broadcast
playlist schedule and we found that with SDN (central controller telling all
the switches what to do) rather than IGMP type system (multicast subscribe
with switches doing a lot more work parsing packets) is the best approach to
handling very large volumes of routes and having them take effect in a low-
latency predictable way.

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kingosticks
Thanks for clarifying, I think I get it. It almost sounds a bit analogous to
an RTOS where you dictate your deadlines to ensure they are met rather than
letting everything run wild and hope for the best.

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gioscarab
See also PJON:
[https://github.com/gioblu/PJON](https://github.com/gioblu/PJON)

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RickJWagner
I never would have looked at an article like this 'till just recently.

Kubernetes changes all that. Now I have an interest in SDN.

