dddvb/docs/octopusnet.multicast

Multicast
---------

Multicast setup supports 2 file formats.
1) Simple variant for the avarage home user
2) More parameters for the expert.

The file is in csv (comma seperated values) format, which can be created with any plain text editor or imported/exported
to/from Microsoft Office Excel or OpenOffice Scalc. With Excel or Scalc care for character set (should be UTF-8) and
column formats is required. First line is contain then column headers.

Standard parameters
-------------------

TITLE: Stream Title

REQUEST: SAT>IP tune request string without the pid parameter. Exact format depends on frontend (DVB-S,DVB-T ..)
use "-" to stream another program from the previous full entry (tuner sharing)

PIDS: Pid list. Must start with a P, the values separated with a colon. "Pall" streams the whole transponder.
(The P is there to ensure Excel or Scalc don't do some fancy format detection, like time conversion)

LANPORTS: Empty or a list with colon separated lan ports starting with L, "Lall" = all ports.
If empty, the stream will only be activated when subscribed with an IGMPv3 request. It will also
only be active on the lan ports through which an IGMPv3 request for the stream has benn received.
(For details how IGMPv3 works look up the relevant RFCs.)
If not empty the stream will be preactived on the listed lan ports (and permanently using bandwidth!).
It still can be subscribed with IGMPv3 on the other ports.


TITLE,REQUEST,PIDS,LANPORTS
"Das Erste","?freq=346&msys=dvbc&sr=6900&mtype=256qam","P0:100:101:104:102:103:106",""
"Bayerisches FS Nord","-","P0:500:201:204:202:203:206",""
"hr-fernsehen","-","P0:300:301:304:302:303",""
"SWR Fernsehen BW","-","P0:800:801:804:802:803:806",""
"WDR Köln","-","P0:600:601:604:602:603",""
"ZDF","?freq=370&msys=dvbc&sr=6900&mtype=256qam","P0:100:110:130:120:121:122:125",""
"ZDF HD","-","P0:6100:6110:6130:6120:6121:6122:6123",""
"zdf neo","-","P0:650:660:680:670:671:672:675",""
"zdf kultur","-","P0:1100:1110:1130:1120:1121:1122:1125",""
"ZDFInfo","-","P0:600:610:630:620:621:622:625",""
"KiKA","-","P0:300:310:330:320:321:325","L3:4:5"
"3sat","-","P0:200:210:230:220:221:222:225",""


Expert parameters:
------------------

PROTO: Protocol, must be "RTP" or "UDP". If you don't know what this means use "RTP".

IP: Multicast IP address, recommended range 239.5.0.0 - 239.126.255.255, see notes below 
about selecting a multicast IP address.

PORT: Destination port. If you don't know what this means set it to 6670

TTL: Time to live used in the IP headers. If you don't know what this means set it to 5.


TITLE,REQUEST,PIDS,PROTO,IP,PORT,TTL,LANPORTS
"Das Erste","?freq=346&msys=dvbc&sr=6900&mtype=256qam","P0:100:101:104:102:103:106","UDP","239.7.7.100",1234,7,""
"Bayerisches FS Nord","-","P0:500:201:204:202:203:206","UDP","239.7.7.101",1234,7,""
"hr-fernsehen","-","P0:300:301:304:302:303","UDP","239.7.7.102",1234,7,""
"SWR Fernsehen BW","-","P0:800:801:804:802:803:806","UDP","239.7.7.103",1234,7,""
"WDR Köln","-","P0:600:601:604:602:603","UDP","239.7.7.104",1234,7,""
"ZDF","?freq=370&msys=dvbc&sr=6900&mtype=256qam","P0:100:110:130:120:121:122:125","UDP","239.7.8.100",1234,7,""
"ZDF HD","-","P0:6100:6110:6130:6120:6121:6122:6123","UDP","239.7.8.101",1234,7,""
"zdf neo","-","P0:650:660:680:670:671:672:675","UDP","239.7.8.102",1234,7,""
"zdf kultur","-","P0:1100:1110:1130:1120:1121:1122:1125","UDP","239.7.8.103",1234,7,""
"ZDFInfo","-","P0:600:610:630:620:621:622:625","UDP","239.7.8.104",1234,7,""
"KiKA","-","P0:300:310:330:320:321:325","UDP","239.7.8.105",1234,7,"L3:4:5"
"3sat","-","P0:200:210:230:220:221:222:225","UDP","239.7.8.106",1234,7,""


Selecting a multicast IP address.
---------------------------------

It is obvious that there should be no conflicts with other services (like UPnP, Windows network ...)
which also use Multicast for communication and advertisments.

For media streaming usually an IP in the range 239.0.0.0 - 239.255.255.255 is used and
will usually only conflict with other media sources. But this is not the whole truth!

The complete IP multicast range is 224.0.0.0 - 255.255.255.254,  that is 536870911 different values.
But there are only 8388608 different Ethernet MAC addresses allocated for IPv4 multicast. That
means a lot of collisions. For example, 239.0.0.22 uses the same MAC address as 224.0.0.22 (IGMP).
This means that 239.0.0.22 can't be blocked in an Ethernet switch without breaking IGMP.
An IP from the range 239.5.0.0 - 239.126.255.255 does not collide with most documented
services, and should be safe to use in most situations and the benefit from IGMPv3 
snooping Ethernet switches.

Multicast and WLAN
------------------

As there is no real support for it (due to encryption) Multicast over WLAN will not work very well.
Therefor it should be avoided to send a out a multicast stream on a lan port there a WLAN router
is connected (at least when the WLAN router is configured as LAN-WLAN bridge).

As long there are free streams on the OctopusNet a RTSP player (including WLAN connected players)
can request any service from a configured multicast source.
For exmaple RTSP://<onetip>/stream=2?pids=0,300,310,330,320,321,325 will request KIKA
as single cast stream from the above example. This is possible even if the entry for KIKA
is removed from the multicast setup.
(the above sample has no free streams left, but it should be clear what is meant)