# no significant improvement from opusFec=true option

**URL:** <https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254>\
**Category:** mediasoup libraries\
**Created:** [June 14, 2020, 3:13am UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254 "2020-06-14T03:13:43Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![geongun20](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/geongun20/32/462_2.png) [@geongun20](https://mediasoup.discourse.group/u/geongun20)\
**Post date:** [June 14, 2020, 3:13am UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/1 "2020-06-14T03:13:43Z")

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I compared with opusFec option is true and false when produce audio track, but couldn’t find any significant difference.

Is there anyone who check effect of this option?

please share your testing result. It would be very helpful

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**Author:** ![nazar-pc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/nazar-pc/32/369_2.png) [@nazar-pc](https://mediasoup.discourse.group/u/nazar-pc)\
**Post date:** [June 14, 2020, 3:51am UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/2 "2020-06-14T03:51:12Z")

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What kind of improvement did you expect?  
It is just FEC, which I think is even enabled by default, so the only improvement you can expect is somewhat more reliable audio in case of networking issues.

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**Author:** ![geongun20](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/geongun20/32/462_2.png) [@geongun20](https://mediasoup.discourse.group/u/geongun20)\
**Post date:** [June 14, 2020, 4:16am UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/3 "2020-06-14T04:16:28Z")

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@nazar-pc yes I hope improvement of QoE when network is not good much.  
A lot of users using my app reports stability, reliablity problem of playing media. I’m trying to improve stability, but Ihave no idea how to do.  
Do you have any recommendations?

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**Author:** ![nazar-pc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/nazar-pc/32/369_2.png) [@nazar-pc](https://mediasoup.discourse.group/u/nazar-pc)\
**Post date:** [June 14, 2020, 4:26am UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/4 "2020-06-14T04:26:52Z")

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You need to find out what is the reason of those issues first. If it is a packet loss - FEC may help, but if it is just networking bandwidth FEC can make things worse instead since it adds redundancy. If you have video alongside audio you may want to tweak priorities for those. I do not think there is a simple answer.

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**Author:** ![TheSalarKhan](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/thesalarkhan/32/630_2.png) [@TheSalarKhan](https://mediasoup.discourse.group/u/TheSalarKhan)\
**Post date:** [June 14, 2020, 1:35pm UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/5 "2020-06-14T13:35:25Z")

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> [@nazar-pc](#):
>
> If you have video alongside audio you may want to tweak priorities for those

Tweak priority as in setting them in the backend using the mediasoup library right?

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<div class="post-metadata">

**Author:** ![nazar-pc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/nazar-pc/32/369_2.png) [@nazar-pc](https://mediasoup.discourse.group/u/nazar-pc)\
**Post date:** [June 14, 2020, 1:56pm UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/6 "2020-06-14T13:56:30Z")

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Yes, check the docs, it is documented there

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<div class="post-metadata">

**Author:** ![TheSalarKhan](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/thesalarkhan/32/630_2.png) [@TheSalarKhan](https://mediasoup.discourse.group/u/TheSalarKhan)\
**Post date:** [June 14, 2020, 2:49pm UTC](https://mediasoup.discourse.group/t/no-significant-improvement-from-opusfec-true-option/1254/7 "2020-06-14T14:49:24Z")

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One more thing that you can do is have a look at mediasoup-demo’s RoomClient.js file.

You will find something like this:

```auto
const PC_PROPRIETARY_CONSTRAINTS =
{
	optional : [{ googDscp: true }]
};

```

Which is passed when creating the consumer:

```auto
this._sendTransport = this._mediasoupDevice.createSendTransport(
					{
						id,
						iceParameters,
						iceCandidates,
						dtlsParameters,
						sctpParameters,
						iceServers : [],
						proprietaryConstraints : PC_PROPRIETARY_CONSTRAINTS
					});

```

This enables Dscp, which is really good for Qos.