TV Set-Top Box & Chromecast Multicast Issues
Photo by Daan Stevens on Unsplash

In Taiwan, TV service is mostly done with digital set-top box(STB) that uses multicast streaming. Connectivity usually goes from provided wifi router to box directly so there isn’t much issue since it’s been pre-configured properly.

If for some reason one wants to use second wifi router behind carrier provided one, there are a few things to configure.

On your own wifi router, check if there’s IPTV option to enable under ‘LAN’ configuration. It typically allows one to turn on IPTV on specific port. If there is, enable it, and connect STB to that port. This is to allow multicast traffic to pass through. If your TV provider uses multicast to stream, enable IGMP Proxy and IGMP Snooping. This is to allow devices such as your phones and chromecast to find each other.

IGMP snooping is the process of listening to Internet Group Management Protocol network traffic to control delivery of IP multicasts. Network switches with IGMP snooping listen in on the IGMP conversation between hosts and routers and maintain a map of which links need which IP multicast transmission.

You ever had issue with chromecast where your phone or tablet can’t seem to see chromecast or YouTube/Netflix is missing that “Cast” icon? That’s because for Chromecast to work consistently under wifi router among devices, IGMP Snooping on WAN setting should be enabled in order for device to see chromecast. I guess chromcast uses multicast to communicate with devices on the network.

And that’s it. You should now see chromecast function working consistently in your app.

Reference:

https://www.snbforums.com/threads/how-to-use-iptv-on-asus-router.30674/
['Mark Lin']
['Chromecast', 'Iptv', 'Network', 'Multicast', 'Wifi']