mpshizzle
Well-Known Member
- Thread starter
- #1
I know this is sure to come up frequently - especially once the trial period ends for non connect + subscribers.
Here's what I know about how Chromecasat works:
Chromecast capable apps search the local network for Chromecast targets using mDNS. This utilizes Port 1900. Once it communicates with said target to discover what capabilities it has. When you initiate casting, it can operate in 2 modes:
1) Streaming From the Internet -
This is the most common mode. When you choose content from your streaming app (Disney +, for example), your phone will gather all of the necessary information to initiate the stream (URL, authorization tokens, etc) and send it to the Chromecast device. At this point the chromecast device begins streaming from the internet
2) Streaming local content -
This is far less common, and is used for things where the source content is not found on the Internet. For example, casting a video from your phone's camera roll.
The key to making all of this work is discovery and communication over a local network. Rivian is achieving this with their hotspot by having the infotainment screen act as a chromecast device that is connected to the network. Since they control all of the firewall and connection rules on the in-vehicle network, they can ensure that all of the ports used for Chromecast discovery and communication are open.
Things change, however, when connect + is no longer active. Without an active internet connection on the in-vehicle network, only locally sourced content is available. Internet based streaming apps are inaccessible to the chromecast device.
Well no worries, you say, we can just connect to the public wifi at the charger. So you connect the Rivian to the hotspot. In this case, the Rivian would have to expose it's own chromecast device on the externally connected network. This poses a problem - suddenly anyone else on the network can cast to your screen, even if they're not in the vehicle. Especially problematic if you're on a public wifi that doesn't implement proper client isolation (that's going to make another appearance later). Who knows what nonsense some teen might decide to cast to your screen
What about using your phone as a hot spot? Sure! That could work.... for some phones. This is where client isolation comes into play again. The idea with client isolation is that devices on a network cannot contact (or even see) each other. They can use the internet and that's it. Some phones implement this on their hotspots. If your phone implements client isolation, that would block chromecast frome being usable.
So between security issues with connecting to extrnal wifi, and issues with only SOME phones allowing for local network communication on the hotspot, it's best to just make Rivian's Chromecast work on the built in hotspot. In this case, it's not just Rivian trying to milk more money out of you. There are valid technical reasons why chromecast must only work via the built in hotspot.
As a side note - I don't yet have the update but based on the wording, it appears that the restriction only applies to casting. It seems as if Rivian WILL allow the built in Youtube app to work on external hotspots. Which, as far as I can see, would have no valid reason to be restricted.
Here's what I know about how Chromecasat works:
Chromecast capable apps search the local network for Chromecast targets using mDNS. This utilizes Port 1900. Once it communicates with said target to discover what capabilities it has. When you initiate casting, it can operate in 2 modes:
1) Streaming From the Internet -
This is the most common mode. When you choose content from your streaming app (Disney +, for example), your phone will gather all of the necessary information to initiate the stream (URL, authorization tokens, etc) and send it to the Chromecast device. At this point the chromecast device begins streaming from the internet
2) Streaming local content -
This is far less common, and is used for things where the source content is not found on the Internet. For example, casting a video from your phone's camera roll.
The key to making all of this work is discovery and communication over a local network. Rivian is achieving this with their hotspot by having the infotainment screen act as a chromecast device that is connected to the network. Since they control all of the firewall and connection rules on the in-vehicle network, they can ensure that all of the ports used for Chromecast discovery and communication are open.
Things change, however, when connect + is no longer active. Without an active internet connection on the in-vehicle network, only locally sourced content is available. Internet based streaming apps are inaccessible to the chromecast device.
Well no worries, you say, we can just connect to the public wifi at the charger. So you connect the Rivian to the hotspot. In this case, the Rivian would have to expose it's own chromecast device on the externally connected network. This poses a problem - suddenly anyone else on the network can cast to your screen, even if they're not in the vehicle. Especially problematic if you're on a public wifi that doesn't implement proper client isolation (that's going to make another appearance later). Who knows what nonsense some teen might decide to cast to your screen
What about using your phone as a hot spot? Sure! That could work.... for some phones. This is where client isolation comes into play again. The idea with client isolation is that devices on a network cannot contact (or even see) each other. They can use the internet and that's it. Some phones implement this on their hotspots. If your phone implements client isolation, that would block chromecast frome being usable.
So between security issues with connecting to extrnal wifi, and issues with only SOME phones allowing for local network communication on the hotspot, it's best to just make Rivian's Chromecast work on the built in hotspot. In this case, it's not just Rivian trying to milk more money out of you. There are valid technical reasons why chromecast must only work via the built in hotspot.
As a side note - I don't yet have the update but based on the wording, it appears that the restriction only applies to casting. It seems as if Rivian WILL allow the built in Youtube app to work on external hotspots. Which, as far as I can see, would have no valid reason to be restricted.
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