# The order of m-lines in answer doesn't match order in offer.

**URL:** <https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341>\
**Category:** mediasoup libraries\
**Created:** [October 18, 2019, 3:53pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341 "2019-10-18T15:53:42Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![eric-jswang](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eric-jswang](https://mediasoup.discourse.group/u/eric-jswang)\
**Post date:** [October 18, 2019, 3:53pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341/1 "2019-10-18T15:53:42Z")

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Hi,  
I am testing mediasoup client with react-native in Android, and encounter the following error at transport.produce( producerOptions ),

**Failed to set remote answer sdp: The order of m-lines in answer doesn’t match order in offer. Rejecting answer.**

This application is based on mediasoup-sample-app ([https://github.com/mkhahani/mediasoup-sample-app](https://github.com/mkhahani/mediasoup-sample-app)). The server (mediasoup server) is running on Ubuntu 18.04, and is working fine with its browser client running on win10.

Here is the react-native environment in use,

- react 16.9.0
- react-native 0.61.2
- react-native-webrtc 1.75.0 (ibc mentioned this version)
- mediasoup-client 3.2.6

Appreciate any advises, Thanks !  
Eric

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**Author:** ![eric-jswang](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eric-jswang](https://mediasoup.discourse.group/u/eric-jswang)\
**Post date:** [October 18, 2019, 4:03pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341/2 "2019-10-18T16:03:54Z")

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Hi,

I found this post ([Send transport sdp offer / answer mismatch in react-native](https://mediasoup.discourse.group/t/send-transport-sdp-offer-answer-mismatch-in-react-native/327)), and will try this fix, Thanks !

Eric

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [October 18, 2019, 4:10pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341/3 "2019-10-18T16:10:07Z")

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And also update react-native-webrtc to the latest version.

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<div class="post-metadata">

**Author:** ![eric-jswang](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eric-jswang](https://mediasoup.discourse.group/u/eric-jswang)\
**Post date:** [October 18, 2019, 4:22pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341/4 "2019-10-18T16:22:27Z")

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OK, Thanks !

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [December 2, 2019, 11:10pm UTC](https://mediasoup.discourse.group/t/the-order-of-m-lines-in-answer-doesnt-match-order-in-offer/341/5 "2019-12-02T23:10:58Z")

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Closed on December 2, 2019, 11:10pm UTC