# Stream servers using multicast

**URL:** <https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689>\
**Category:** API\
**Created:** [June 12, 2017, 6:13pm UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689 "2017-06-12T18:13:45Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![kripple](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/kripple/32/2888_2.png) [@kripple](https://discuss.dev.twitch.com/u/kripple)\
**Post date:** [June 12, 2017, 6:13pm UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/1 "2017-06-12T18:13:45Z")

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This is not about the API but there didn’t seem to be a better forum topic.

Is there specific reason why users have to specify which (location-based) server they’re streaming to?  
Is there a reason the ingest servers don’t use multicast/geocast?

I’m seeing a situation where they’d be allowing a US east client stream to a US west server or vise versa. This thought leads me to: why would the client want to do this?

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**Author:** ![george](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/george/32/120_2.png) [@george](https://discuss.dev.twitch.com/u/george)\
**Post date:** [June 12, 2017, 10:42pm UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/2 "2017-06-12T22:42:42Z")

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There used to be one but I don’t think many users actually used it. Most seem to prefer changing the locations manually to find the option that works the best for their location and ISP.

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**Author:** ![matt\_thomas](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/matt_thomas/32/710_2.png) [@matt\_thomas](https://discuss.dev.twitch.com/u/matt_thomas)\
**Post date:** [June 12, 2017, 11:40pm UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/3 "2017-06-12T23:40:32Z")

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There is a round robin - “[live.twitch.tv](http://live.twitch.tv)” but I never saw anycast/multicast/geocast. As george stated, there might be issues the user is having with the route and prefer to set another nearby manually. Although something like anycast should technically prevent this as choose the best/healthiest/shortest route. But that won’t help if the actual ingest is having issues.

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**Author:** ![george](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/george/32/120_2.png) [@george](https://discuss.dev.twitch.com/u/george)\
**Post date:** [June 12, 2017, 11:54pm UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/4 "2017-06-12T23:54:07Z")

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[live.twitch.tv](http://live.twitch.tv) is US West: San Francisio.

The old “global load balancing service” was [live-3c.justin.tv](http://live-3c.justin.tv). I’m not sure how it was implemented but it never worked very well so eventually it was quietly removed. This was from back in the day when FMLE was still the streaming application of choice (and you had to manually enter the RTMP server in the application), XSplit was still getting started and no one know what an OBS was.

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**Author:** ![matt\_thomas](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/matt_thomas/32/710_2.png) [@matt\_thomas](https://discuss.dev.twitch.com/u/matt_thomas)\
**Post date:** [June 13, 2017, 12:04am UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/5 "2017-06-13T00:04:46Z")

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It’s not US West: San Francisco according to it’s DNS entry:

; \<\<\>\> DiG 9.3.6-P1-RedHat-9.3.6-25.P1.el5\_11.12 \<\<\>\> [live.twitch.tv](http://live.twitch.tv)  
;; global options: printcmd  
;; Got answer:  
;; -\>\>HEADER\<\<- opcode: QUERY, status: NOERROR, id: 15514  
;; flags: qr rd ra; QUERY: 1, ANSWER: 16, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:  
;[live.twitch.tv](http://live.twitch.tv). IN A

;; ANSWER SECTION:  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.82  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.83  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.86  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.84  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.81  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.84  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.80  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.83  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.81  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.85  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.85  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.90  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.80  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.86  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 192.108.239.82  
[live.twitch.tv](http://live.twitch.tv). 59 IN A 23.160.0.89

;; Query time: 46 msec  
;; SERVER: 8.8.8.8#53(8.8.8.8)  
;; WHEN: Mon Jun 12 19:30:47 2017  
;; MSG SIZE rcvd: 288

**EDIT: Foot in mouth, made some incorrect assumptions. This is US West, San Francisco**

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**Author:** ![george](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/george/32/120_2.png) [@george](https://discuss.dev.twitch.com/u/george)\
**Post date:** [June 13, 2017, 12:08am UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/6 "2017-06-13T00:08:06Z")

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Seems like SFO to me:

 ![](https://d2opxh93rbxzdn.cloudfront.net/original/2X/b/b6635eb73dc090aa674a2985839dbd1ef94f2c45.png)

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<div class="post-metadata">

**Author:** ![matt\_thomas](https://d3ovvz0v2ajtpu.cloudfront.net/user_avatar/discuss.dev.twitch.com/matt_thomas/32/710_2.png) [@matt\_thomas](https://discuss.dev.twitch.com/u/matt_thomas)\
**Post date:** [June 13, 2017, 12:10am UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/7 "2017-06-13T00:10:40Z")

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I suppose I should have looked at all the rdns entires first. 🙂

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**Author:** ![system](https://d2opxh93rbxzdn.cloudfront.net/original/2X/0/05909729875cce3b53e59d5561c4d23bb14948fc.png) [@system](https://discuss.dev.twitch.com/u/system)\
**Post date:** [July 13, 2017, 12:24am UTC](https://discuss.dev.twitch.com/t/stream-servers-using-multicast/10689/8 "2017-07-13T00:24:53Z")

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