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Re: Subject: I-D ACTION:draft-fair-ipdvb-req-01.txt
Since submitting this ID -01, I drew the following new figures
that I'd like comments on - with a view to placing in the
next rev. (see below).
Gorry
Dr G Fairhurst wrote:
>
> The following was announced on the IETF Announce list:
>
> "Requirements for transmission of IP datagrams over DVB networks",
> H Clausen, G Fairhurst, 05/09/2002. (70832 bytes)
>
> http://www.ietf.org/internet-drafts/draft-fair-ipdvb-req-01.txt
>
<<snip>>
TS-logical Channel Figure
-------------------------
TS-LC-A-1 /---\--------------------/---\
\ / \ / \
\ | | | |
TS-LC-A-2 ----------- | | -------------
-------------------- | | -------------
| | | |
/-------- / | -------------
/ \----/-------------------\----/
TS-LC-A-3/ MPEG-2 TS MUX A
/
TS-LC /
------------X
\ TS-LC-B-4 /---\------------------------/---\
\ / \ / \
\ | | | |
TS-LC-B-2 \----------- | | ---------
-------------------- | | ---------
| | | |
/-------- / | ---------
/ \----/-----------------------\----/
/ MPEG-2 TS MUX B
TS-LC-B-1
Figure 2: Example showing MPEG-2 TS Logical Channels carried over
2 MPEG-2 TS Multiplexes.
The above figure shows two MPEG-2 TS Multiplexes (A and B). In this
case,
each multiplex carries 3 MPEG-2 TS Logical Channels. These Logical
Channels
may differ (TS-LC-A-1, TS-LC-A-2, TS-LC-B-2, TS-LC-B-1). Logical
Channels
are independently numbered on each MPEG-2 TS Mux. In most cases the
data
sent over the Logical Channels will differ for different multiplexes.
There
are cases where the same data may be distributed over two or more
multiplexes (e.g., some SI tables; multicast content which needs to be
received by receivers tuned to either MPEG-2 TS; unicast data were the
receiver may be in either/both two potentially overlapping MPEG-2
transmission cells).
----
Block Diagram
-------------
In a simple example, one or more TS are processed by a MPEG-2
multiplexor
resulting in a TS Multiplex. That is forwarded over a physical bearer
towards one or more receivers. See figure 3.
+------------+ +------------+
| IP | | IP |
| End Host | | End Host |
+-----+------+ +------------+
| ^
+------------>+---------------+ |
+ IP | |
+-------------+ Encapsulator | |
SI-Data | +------+--------+ |
+-------+-------+ |MPEG-2 TS Logical Channel |
| MPEG-2 | | |
| SI Tables | | |
+-------+-------+ ->+------+--------+ |
| -->| MPEG-2 | |
+------------>+ Multiplexor | |
MPEG-2 TS +------*--------+ |
Logical Channel |MPEG-2 TS Mux |
| |
Other ->+------+--------+ |
MPEG-2 -->+ MPEG-2 | |
TS --->+ Multiplexor | |
---->+------+--------+ |
|MPEG-2 TS Mux |
| |
+------+--------+ +------+-----+
|Physical Layer | | MPEG-2 |
|Modulator +---------->+ Receiver |
+---------------+ MPEG-2 +------------+
TS Mux
Figure 3: An example configuration for a uni-directional service
for IP transport over MPEG-2
This is still very much a work in progress, and we would
welcome input and ideas for the areas of address resolution
(IP address to DVB TS logical channel mapping), layer 2 signals
(MPEG-2 to/from IP router), QoS, service discovery, etc.
Gorry