demo stream, filter questions

["Karsten Siebert" <Karsten.Siebert@sv-gmbh.de>]

After reading the IP/DVB drafts we've implemented a sample encapsulation mode in our encapsulator (see below) and passed some data, to see, if the normal section packing method (without use of adaptation field) would be efficient enough for the receiver to de-capsulate the payload. And yes, PUSI and length are efficient to re-construct the payload (even when packed). We've just passed entire MAC frames over the link in this sample (also do not worry about the type, we've just picked 0x800 in the example).

 

What comes in mind here is that the MPE header is used as hardware filtering at "MAC/Section" level also. DVB streams are normally high speed streams (in the future > 100 mbps packet throughput (QAM, 8PSK)). I cannot imagine, that a standard receiver filters at IP or similar levels in software. MPE has the MAC address field, which tells the local hardware to set a section level filter. The "minimal header has no such capability. Will receivers get all packets on that PID ? How do you build groups of receiver devices ?

 

 

 

Karsten

 

 

(In case one is interested we also have colored pdf version of the demo output for better visibility of individual bytes)

 

 

The demo system transmits complete Ethernet frames, section_type (equal to Ethernet protocol identifier) is copied from Ethernet header. section_length = tot_len of section - 4 (in bytes).

 

Syntax      No. of bits  Identifier

 

MPM_section() {

 

   section_type        16 uimsbf
   section_length      16 uimsbf

 

   for(i=0; i<N; i++) {
         data_byte [i]  8 bslbf
   }

 

   section_crc32      32 rpchof
}

 

Two UDP packets (100 byte payload "a"),
Section packing disabled, PID 0x64,
PUSI set in both TS packets,
Pointer byte set in both TS packets,

 

Packet length 188
4740641700080000920002a0b0c0d00002a0b0c0d00800450000802097000040
11d872c0a80009c0a8000a04000312006c719b61616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
616161616161616161616161616161616161616161616134087b04ffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffff

 

Packet length 188
4740641800080000920002a0b0c0d00002a0b0c0d00800450000802098000040
11d871c0a80009c0a8000a04000312006c719b61616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
616161616161616161616161616161616161616161616145e70541ffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffff

 

Two UDP packets (100 byte payload "a"),
Section packing enabled, PID 0x64,
PUSI set in first TS packet,
Pointer byte set in first TS packet,

 

Packet length 188
4740641900080000920002a0b0c0d00002a0b0c0d00800450000802099000040
11d870c0a80009c0a8000a04000312006c719b61616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
61616161616161616161616161616161616161616161619710a3130800009200
02a0b0c0d00002a0b0c0d0080045000080209a00004011d86fc0a800

 

Packet length 188
4700641a09c0a8000a04000312006c719b616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
616161616161616161616161616161616161616161c818168bffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffff
 
Three UDP packets (100 byte payload "a"),
Section packing enabled, PID 0x64,
PUSI set in first two TS packets,
Pointer byte set in first two TS packets,

 

Packet length 188
4740641b00080000920002a0b0c0d00002a0b0c0d0080045000080209b000040
11d86ec0a80009c0a8000a04000312006c719b61616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
61616161616161616161616161616161616161616161611aefb0d90800009200
02a0b0c0d00002a0b0c0d0080045000080209c00004011d86dc0a800

 

Packet length 188
4740641c7509c0a8000a04000312006c719b6161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
61616161616161616161616161616161616161616161949b3409080000920002
a0b0c0d00002a0b0c0d0080045000080209d00004011d86cc0a80009c0a8000a
04000312006c719b6161616161616161616161616161616161616161

 

Packet length 188
4700641d61616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161616161616161616161616161
6161616161616161616161616161616161616161466c925bffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffff