Testing the Multicast Network


The easiest way to test the multicast system is to start a multicast-enabled broadcast publishing point, and then attempt to connect to the stream from players around the network. When you do so, enable the Deny new unicast connections option on the publishing point and do not enable unicast rollover. This will force clients to connect to the multicast stream only. You can also select only the multicast streaming protocol on the Network tab of the Options dialog box in Windows Media Player.

Because multicast is connectionless, there is no way to check whether clients can receive a multicast stream other than attempting to open a stream on the client. Multicasting is similar to television broadcasting in that respect. The only way to receive feedback from a client is to enable multicast logging. With logging enabled, clients send usage information to a logging URL on a Web server when the end user closes the stream.

For detailed information about the activity on a given router or interface, you can run debug or display commands. By monitoring debug information, you can see every message sent and command executed on the interface. For example, the following sample debug output is from a router.

09:41:16: PIM: Received v2 Hello on Serial1 from 172.161.4.1 09:41:16: PIM: Received v2 Hello on Serial0 from 172.161.3.12 09:41:16: PIM: Send v2 Hello on Serial0 09:41:16: PIM: Send v2 Hello on Serial1 09:42:03: PIM: Received v2 Join/Prune on Serial1 from 172.161.4.1 09:42:03: PIM: Join-list (*,224.3.5.45) RP 172.161.2.2, RPT-bit set,  WC-bit set, S-bit set

In the last two lines of the debug output, a join request is received on the Serial1 interface, and the join is implemented and added to the oilist.

You can also use the command-line tool Mcast.exe, available in the Windows 2000 Server Resource Kit. You can use Mcast.exe to send multicast packets or listen for multicast packets sent to a multicast group address in order to test multicast connectivity between hosts on a network. You could do the same thing with a server and Player. However, Mcast.exe can be faster and easier to use when you simply want to check connectivity. For example, you could configure Mcast.exe on one host to send 10 packets with a given source and group address, and then configure Mcast.exe on a second host to listen for the packets and print the results on the screen.

After the switches and routers have been multicast-enabled, configured for IGMPv2 and PIM-SMv2, and the system has been tested to make sure multicast traffic is forwarded as expected, the system will be able to stream multicast broadcasts across the company. All the Fabrikam technicians have to do is configure a broadcast publishing point for multicast and begin streaming. The leaf router connected to the source will automatically register the stream with the RP, and end users will be able to receive the broadcast on their Players.

With the network multicast-enabled, the Fabrikam streaming media system is fully prepared to deliver on-demand and broadcast content to every desktop, conference room, and resource center computer in the company. In the next chapter, we explore ways to compile usage logs into reports that can be used for planning content creation and making improvements to the network.




Microsoft Windows Media Resource Kit
Microsoft Windows Media Resource Kit (Pro-Resource Kit)
ISBN: 0735618070
EAN: 2147483647
Year: 2005
Pages: 258

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