Cisco Cisco 5520 Wireless Controller 기술 참조
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Chromecast Deployment Guide, Release 7.6
What is Chromecast?
What is Chromecast?
Chromecast is a digital media player developed by Google. The device, a HDMI dongle, plays
audio/video content on a high-definition screen by directly streaming it via Wi-Fi from the Internet or a
local network. Users select the media to play by using Chromecast enabled mobile/Web applications, or
through a feature called “tab casting” that can mirror most Google Chrome browser content running on
the device (MAC OSX and Windows).
audio/video content on a high-definition screen by directly streaming it via Wi-Fi from the Internet or a
local network. Users select the media to play by using Chromecast enabled mobile/Web applications, or
through a feature called “tab casting” that can mirror most Google Chrome browser content running on
the device (MAC OSX and Windows).
Chromecast uses a simple multicast protocol for Discovery And Launch that enables users to mirror their
devices on a second screen.
devices on a second screen.
The Chromecast devices operate on DIAL protocol. The DIAL Service Discovery enables a client to
discover DIAL Server (Chromecast) on its local network, and obtain access to those services. This is
achieved by using a new search target within the SSDP defined by uPNP.
discover DIAL Server (Chromecast) on its local network, and obtain access to those services. This is
achieved by using a new search target within the SSDP defined by uPNP.
The clients that wishes to discover Chromecast servers send a request over UDP to IP address
239.255.255.250 and UDP port number 1900. See
239.255.255.250 and UDP port number 1900. See
information.
Problem Statement
The multicast address used by the Chromecast discovery packets has a TTL (Time To Live) set to 1.
Routers cannot use multicast routing to redirect traffic across L2 subnets because this results in only link
local discovery of Chromecast, which might not be ideal for larger networks.
Routers cannot use multicast routing to redirect traffic across L2 subnets because this results in only link
local discovery of Chromecast, which might not be ideal for larger networks.
This document provides information on deploying Chromecast over large networks with single, as well
as multiple VLANs.
as multiple VLANs.
1. (Service Discovery Request)
1. (Response with IP address of service)
352546
Unicast Response
239.255.255.250
352547
239.255.255.250
VLAN Y
VLAN X
VLAN X
Chromecast Multicast
discovery can’t be Routed
discovery can’t be Routed
CAPWAP Tunnel
CAPWAP