Channel bonding for live stream video

hey everybody,
Im testing both the max hd 4 and the SpeedFusion Engine for live video streaming.
for the max hd 4 im only using 4 sim card. i noticed while using 4 sim cards at the sime time (bonding them) clearly there is more data passing )seeing it in speed test) but the video is not better than using only 1 sim.
is it posiible? what can i do to make it better?

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Hi and Welcome to the forum!
Live video streaming is always a question of getting the cleanest connection possible so that encoded video running over the top has the best possible journey ( ie shortest path, least amount of packet loss). However, how you tweak and adjust the things you can to fine tune that connection depends on your requirement.

I’ve worked with customers who need the most reliable video stream possible with the lowest latency (<100ms) and who use WAN smoothing to duplicate the video stream 4 times across all cellular WAN links to make that happen. The compromise is that a single 4Mbps Video stream consumes more than 16Mbps of cellular data.

I’ve also worked with customers who want the most bandwidth possible and don’t care about latency. So we add network buffers everywhere (increasing latency to more than 2 secs), turn on Forward Error correction, and up the the bitrate on the encoder. I’ve done 100Mbps streams over cellular reliably between countries this way for live remotely produced studio shows.

What type of live stream are you doing? Is high bandwidth more important than low latency?

It sounds like you are getting congestion on your cellular links when you combine 2 or more. The first thing I would try is Dynamic Weighted Bonding as that is proving very successful for me in multi-cellular deployments. Then enable WAN smoothing if DWB is not enough.

Good luck!

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And are you using SRT in your encoder?

Hi @MartinLangmaid
You always have good answers on this forum, I’ve been reading a lot of information lately as recently adopted the Pepwave infrastructure at the beginning of the year. And you’re from my home county of Devon too which is awesome!

My question about livestreaming is what settings on the pepwave will give me greatest resiliency, and when should I use bandwidth over latency? For my zoom webinars I just have a rule which sends the zoom traffic to my Fusionhub wan smooth tunnel via Saas in ic2, but what about video broadcast? I stream to Facebook live, Vimeo and YouTube and have had some luck with the FEC tunnel but have been running into bandwidth issues and breakups using LTE wans. Especially OBS which I get severe packet loss whenever I enable FEC! If I’m streaming between 4 and 10mbps, should I even be concerned about latency, and how would I go about prioritising the bandwidth on the FEC tunnel?


Another Devonian! I suspect we are a rare breed on here :wink:

If you have enough bandwidth WAN Smoothing set to high. If you don’t have enough bandwidth everything you do after is a compromise.

Typically I show my streaming customers how to run WAN bandwidth tests and SpeedFusion bandwidth tests to work out how much quality bandwidth they have, and then we will typically use FEC and Dynamic Weighted Bonding most often with a hard bandwidth limit set in the tunnel sometimes too.

You can prioritise bandwidth when latency doesn’t matter. If you are hosting a panel based webinar with back and forth conversations, (low)latency will be king since interacting in real time with anything works best when latency is low. (which reminds me Dave Reynolds at Realm pictures is another Devonian and his use case makes this point well Realm Pictures Interview - Peplink Software Defined WAN - YouTube)

If you are just presenting, or using a 3rd party hardware encoder to stream video from a wedding or sports event, that encoder could well be adding 2-4 secs of latency in the video stream anyway so adding a little more buffers in the underlying IP stream won’t matter in practical terms or user experience.

I most often see issues on LTE when upload becomes saturated and there is buffer bloat. Dynamic weighted bonding is often a cure, or a hard upload bandwidth limit that is at 90% of the measured available bandwidth over the links can help also.

Hi @MartinLangmaid,

I will give that a go. If I’m at a location I will usually test the LTE WANs individually, then the combined bonded throughput using the Pepvpn speedtest in the router. So you reckon use the FEC tunnel to my local fusionhub, with FEC and DWB enabled on the tunnel for best one-way video streams? I have noticed that OBS really hates both FEC and DWB but I will try it with my hardware encoder! And what about the receive buffer? would that be a useful thing? How does it work? I have tuned the DWB tunnel very well now using the cut off and suspension values.

Why does a hard upload limit help?

I currently have my zoom webinars on the WAN smoothing tunnel set to normal, so as zoom is a pretty low bandwidth hogger and if my speedtests show I can cope with the bandwidth, you reckon I should set Smoothing to high? I thought ‘normal’ duplicates every packet down all the links anyway?

Thanks again