# UDP: how to enable NACK with Wowza Streaming Engine XML? **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [January 3, 2021, 12:24am UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624 "2021-01-03T00:24:44Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Jason\_Nottingham](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@Jason\_Nottingham](https://community.wowza.com/u/Jason_Nottingham)\ **Post date:** [January 3, 2021, 12:24am UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/1 "2021-01-03T00:24:44Z")
I searched here for ‘NACK’ and didn’t find a good match in the top results. > **[Set up WebRTC streaming with Wowza Streaming Engine](https://www.wowza.com/docs/how-to-use-webrtc-with-wowza-streaming-engine)** > > Learn how to stream WebRTC with Wowza Streaming Engine. says > **Note:** If you use UDP ICE candidates, enabling NACK messages is recommended to allow for retransmission of lost packets. See the optional RTP properties in Configure a live application for information about how to enable NACK with Wowza Streaming Engine XML. that page it links to (I can’t relink it here because this forums software thinks I am a new user trying to link more than 2 urls) isn’t showing me information about enabling NACK. When I use the search function I am not currently finding it on [wowza.com](http://wowza.com). ---
**Author:** ![Jason\_Nottingham](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@Jason\_Nottingham](https://community.wowza.com/u/Jason_Nottingham)\ **Post date:** [January 3, 2021, 12:25am UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/2 "2021-01-03T00:25:36Z")
This is the linked page (forum software wouldn’t let me post with it in) [https://www.wowza.com/docs/how-to-use-webrtc-with-wowza-streaming-engine#configure-a-live-application](https://www.wowza.com/docs/how-to-use-webrtc-with-wowza-streaming-engine#configure-a-live-application) ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [January 4, 2021, 5:47pm UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/3 "2021-01-04T17:47:27Z")
So sorry that wasn’t easier to find for you. It looks like you found it and I would suggest to others that in addition to searching in the forums, look for documentation by also trying the the [search bar](https://www.wowza.com/docs) on the wowza documentation page. Let me share the info though from the correct article [HERE](https://www.wowza.com/docs/how-to-use-webrtc-with-wowza-streaming-engine) - you will need to click on **SEE THE STEPS** for the dropdown of properties to appear. ![Screen Shot 2021-01-04 at 12.35.17 PM](https://us1.discourse-cdn.com/flex002/uploads/wowza1/original/1X/d122690ab3ad2ab3d70ddcf2b9d8080d67850e2b.png) Scroll down to this property in the article. ![Screen Shot 2021-01-04 at 12.35.02 PM](https://us1.discourse-cdn.com/flex002/uploads/wowza1/original/1X/75bc6ea97c07c570433aab546896086ff89e93ef.png) **To configure this property in the xml:** To handle out of order and retransmitted packets for WebRTC publishing, add the following optional RTP definitions, including **Name** , **Type** (where applicable), and **Value** , to the ` / ` container in the **[_install-dir_]/conf/[_applicationName_]/Application.xml** file. ---
**Author:** ![Jason\_Nottingham](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@Jason\_Nottingham](https://community.wowza.com/u/Jason_Nottingham)\ **Post date:** [January 5, 2021, 5:41am UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/4 "2021-01-05T05:41:22Z")
Thanks! I hadn’t realized the search at the top of this page excluded docs - will keep that in-mind in the future. And I had ctrl+f searched that page for ‘nack’ - forgot to expand/click the links before searching. ---
**Author:** ![video\_streaming](https://avatars.discourse-cdn.com/v4/letter/v/22d042/32.png) [@video\_streaming](https://community.wowza.com/u/video_streaming)\ **Post date:** [January 5, 2021, 6:37pm UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/5 "2021-01-05T18:37:50Z")
No worries- it is a bit buried, so we’ll try to improve the process to find it! ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [March 9, 2021, 7:02pm UTC](https://community.wowza.com/t/udp-how-to-enable-nack-with-wowza-streaming-engine-xml/92624/6 "2021-03-09T19:02:16Z")
In [Wowza Streaming Engine 4.8.10](https://www.wowza.com/docs/wowza-streaming-engine-4-8-10-release-notes#details) - Fixed an issue with RTCP NACK messages not being correctly rate-limited with WebRTC streams.