Operation Manual

NOXON iRadio Cube
ENGLISH 53
C - Dealing with tough network problems...
C1 - The necessary basic knowledge
Time to get technical! At this point we will be taking a closer look at what happens when establishing a
connection between the NOXON and the media or music server. While it might seem a bit dry and obscure
for the layman, possessing this knowledge will make a definite impression in certain circles. But of course,
it would be even better if it were to help you get to the bottom of any communication problems between
the server and the NOXON. Unfortunately, from time to time it may be impossible to establish a connection
to the media server. Problems that cannot be solved with the information provided earlier tend to be non-
trivial, but a systematic approach can nevertheless pinpoint them fairly quickly.
Performing the troubleshooting work takes basic knowledge of network
technology and an understanding of some specialised terminology.
My type, your type. As a rule, the current version of the Internet protocol (IPv4) distinguishes between A, B,
C and MC address ranges. With the exception of the MC network, they are very similar technically and
roughly describe the size and scope of the network (number of computers per network). The smallest net-
work type, the C network for a maximum of 254 computers, is generally used in home environments. As
described above, most of the computers then "answer" to addresses such as 192.168.0.100,
192.168.0.55 or similar, sharing the first three blocks, i.e. 192.168.0. All of the computers on the network
can be reached via a single IP address, the so-called broadcast address, 192.168.0.255 (in the network,
192.168.0.0/24). A slight modification of this technique is used by our NOXON. If you have set everything
up correctly, the NOXON will be located in the same network address range as the music server. Let's have
a closer look at the connection process.
The music server starts and sends a broadcast ("Hello, I'm a music server and this is my address!") to the
address 239.255.255.250. This address is in the MC or multicast range (similar to a broadcast address like
the one above, but one that reaches all lower-level networks at the same time) and will be received by all
devices, including the NOXON. The NOXON continuously monitors port 1900 for such broadcasts in order to
detect new media server friends.
Note: The SSDP service is used by Windows to detect Universal Plug & Play components such as our
NOXON. The service is enabled by default in Windows XP and searches in the background for suitable de-
vices.
The NOXON, on the other hand, sends a normal TCP/IP connection request to the target port 8080 (HTTP),
transmitting its so-called client description to the music server. This description contains information on
the NOXON and what it can play.
The server in turn sends a detailed description of itself (server, version and available services) to the
NOXON. Everything is provided by the music server, depending also on the server's version and type. If you
decide to sort by ARTIST, for example, the NOXON will send a query to the server ("Send me a list of all of
the artists you have stored!"). The server will then send the contents of the directory, in this case the
ARTIST list according to the filter rules transmitted by the NOXON.
Select a track to play and the music server will transfer it. The server will start the transfer on port 1024,
but will change it regularly during the transmission.