Community discussions

MikroTik App
 
luccas
just joined
Topic Author
Posts: 3
Joined: Wed Apr 20, 2022 1:01 pm

Minimum bandwidth for a video

Wed Apr 20, 2022 1:13 pm

Hi,
I have a question if the following situations can be easily solved:

Video streamer (TCP / 11500) --- router mikrotik --- switch --- SXT 5AC <.....> client SXTq --- router --- IPbox.

If the client is watching a video stream approx. 10Mb / s and other client users will start downloading, so the video will start to chop.

Is it possible to set the minimum bandwidth for a video stream at a wireless link to a client when the total bandwidth is variable (weather, ...)?

I apologize for my English and I believe it is understandable.

Thank you, Luk
 
User avatar
anav
Forum Guru
Forum Guru
Posts: 19099
Joined: Sun Feb 18, 2018 11:28 pm
Location: Nova Scotia, Canada
Contact:

Re: Minimum bandwidth for a video

Thu Apr 21, 2022 4:55 pm

Most people state somewhere between 20-30 Mbps for 4K is a minimum.
For 1080P, 10Mbps should suffice.
If you have multiple streams that may be problematic..... not sure if its incrementally increased or additively increased.
 
luccas
just joined
Topic Author
Posts: 3
Joined: Wed Apr 20, 2022 1:01 pm

Re: Minimum bandwidth for a video

Thu Apr 21, 2022 5:05 pm

I need to set a priority or reserved bandwidth for this service.

The client has a radio speed between 50 and 80Mbps. And if he watches video, he will always have the available speed (for example 10Mbps). And the free capacity of 40 to 70Mbps will be free for download.
 
enlace101
newbie
Posts: 48
Joined: Thu Jan 03, 2019 8:03 pm

Re: Minimum bandwidth for a video

Thu Apr 21, 2022 7:34 pm

If you want to ensure 10Mbps to connections with a specific port. it's possible.

I do this in the following way

-First, I would mark the connection and packets defining the port and the rest (Mangle)
-Second would generate Queue Type PCQ Down and UP
-Third, it would generate a queue tree with the priorities

In this way you will always have a total flow, but it will give guaranteed priority to said port.

At least that's what I do, and I ensure flow for Ping, DNS and Webs

I hope it helps something.

translated text with google
 
luccas
just joined
Topic Author
Posts: 3
Joined: Wed Apr 20, 2022 1:01 pm

Re: Minimum bandwidth for a video

Wed Apr 27, 2022 7:22 pm

I tried to create this configuration and it looks right.

/ip firewall mangle
add action=mark-connection chain=prerouting dst-port=11500 \
    new-connection-mark=IPTV-Conn passthrough=yes protocol=tcp
add action=mark-packet chain=prerouting connection-mark=\
    IPTV-Conn new-packet-mark=IPTV passthrough=no

/queue tree
add limit-at=100M max-limit=100M name=Download parent=ether1
add limit-at=15M max-limit=20M name=TV packet-mark=IPTV parent=\
    Download priority=5
add name=XOthers packet-mark=no-mark parent=Download priority=1 \
    queue=pcq-download-default
 
tangent
Forum Guru
Forum Guru
Posts: 1351
Joined: Thu Jul 01, 2021 3:15 pm
Contact:

Re: Minimum bandwidth for a video

Thu Apr 28, 2022 1:11 am

new-connection-mark=IPTV-Conn...add limit-at=15M max-limit=20M

While you can in principle get 20 Mbit/sec HD IPTV streams to work over WiFi, others downloading at the same time over the same shared medium — as in your original complaint — is not your only likely problem.

This looks like the classic sort of IPTV system where, if you're watching a 30fps video stream, each frame of video arrives at your LAN as close to 1/30th of a second apart as to not be worth quibbling over. This is the original definition of the word "streaming:" each bit of content arrives just in time to be played back, because the buffers in the sort of STBs used in those systems tend to be quite small by today's standards. They might buffer as much as half a second of video, but likely little more.

Contrast the likes of YouTube, NetFlix, etc., which may buffer 5-30 seconds of video before they begin playing it. Back when network speeds were closer to the size of the stream (e.g. 10 Mbit/sec with a 5 Mbit/sec HD video stream) you could see this buffering step occur before playback began. Now it happens in a fraction of a second in typical cases, but it still happens.

You may then ask, "Half a second is ~15 frames of video, so doesn't the IPTV system have that long to sort transient problems out before things start going bad?" Answer: no.

First off, classic IPTV streaming is a UDP-based protocol, meaning no retransmissions. A frame either gets to its destination intact, or it does not. If a frame spans 10 UDP packets, you only have to lose one to lose the whole frame, under many encodings.

Second, all "delivery" type video codecs for the past 3 decades work by making most frames refer to surrounding frames, to save bandwidth. "This frame is like that one over there, but with this section shifted right a bit, but also like that one over there…" This means that an error in delivery or decoding of one frame is likely to affect the 10-100 frames surrounding it, with typical encoding settings.

If your WiFi uses the 2.4 GHz spectrum, you can run into these sort of problems simply by someone nearby turning on the microwave oven, causing seconds worth of bad playback.

Or, it might work fine until you decide to have a house party, putting too many ugly bags of mostly water between the sender and receiver, causing dropouts, since the very reason microwave ovens are effective is that water absorbs 2.4 GHz radiation.

My advice: stop trying to make WiFi do something it is ill-suited to. Run IPTV over wired connections, always and only.

Either that, or switch to over-the-top pseduo-streaming services like NetFlix, which are TCP-based and heavily buffered, which is why they work in the face of such problems.
 
User avatar
Buckeye
Forum Veteran
Forum Veteran
Posts: 887
Joined: Tue Sep 11, 2018 2:03 am
Location: Ohio, USA

Re: Minimum bandwidth for a video

Fri Apr 29, 2022 5:58 am

My advice: stop trying to make WiFi do something it is ill-suited to. Run IPTV over wired connections, always and only.
As usual, good advice with good backup evidence.
Thanks for taking the time to post more than one line answers. I usually learn something useful from your posts.
 
User avatar
bpwl
Forum Guru
Forum Guru
Posts: 2983
Joined: Mon Apr 08, 2019 1:16 am

Re: Minimum bandwidth for a video

Tue Nov 08, 2022 5:52 pm

Similar posts grrrr ...|@# .... see viewtopic.php?p=966540#p966540

Who is online

Users browsing this forum: silverbios, spookymulder84, Vyizis and 26 guests