# WebRtcServer empty iceCandidates

**URL:** https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780
**Category:** mediasoup libraries
**Created:** [December 22, 2022, 8:09am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780 "2022-12-22T08:09:33Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![imkarmadev](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/imkarmadev/32/914_2.png) [@imkarmadev](https://mediasoup.discourse.group/u/imkarmadev)
#### Post date: [December 22, 2022, 8:09am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780/1 "2022-12-22T08:09:33Z")

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Hi,

I created createWebRtcTransport in the old way, but now I wona update the code base to use WebRtcServer and pass as a field WebRtcServer instanse, but got error empty iceCandidates [method:router.createWebRtcTransportWithServer]. If switch back to the old way all works. What did I do wrong?

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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 22, 2022, 9:27am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780/2 "2022-12-22T09:27:55Z")

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So you are not passing proper listenInfos in worker.createWebRtcServer() or you are not passing proper enableUdp and/or enableTcp to router.createWebRtcTransport().

Please check both APIs in the docs.

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### Author: ![imkarmadev](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/imkarmadev/32/914_2.png) [@imkarmadev](https://mediasoup.discourse.group/u/imkarmadev)
#### Post date: [December 22, 2022, 9:34am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780/3 "2022-12-22T09:34:35Z")

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setting up enableTcp help, but I wonder why I did pass this params in the old way using createWebRtcTransport and it work

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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 22, 2022, 9:49am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780/4 "2022-12-22T09:49:49Z")

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Have you read the API docs as I suggested? Or did you just added enableTcp:true?

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<div class="post-metadata">

### Author: ![imkarmadev](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/imkarmadev/32/914_2.png) [@imkarmadev](https://mediasoup.discourse.group/u/imkarmadev)
#### Post date: [December 22, 2022, 10:07am UTC](https://mediasoup.discourse.group/t/webrtcserver-empty-icecandidates/4780/5 "2022-12-22T10:07:46Z")

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just enableTcp:true