Sending more RTP packets continues

As i am a traveling today, i will update this blog later tomorrow as well. The goal is to send more RTP packets given the first one has been successfully sent.

Here is the hex dump of the first packet taken from Wireshark. A entire row of 1280 pixels in a 720p frame is sent as three packets of 1272 bytes (424 pixels) , 1272 bytes (424 pixels) and 1296 bytes (432 pixels). I have annotated for the sake of clarity. The payload is monotonically increasing numbers from 0 to 423.


Orange highlight shows Ethernet header
Green highlight shows IP header
Yellow highlight shows UDP header
Blue highlight show RTP header
Pink highlight shows RTP payload


782bcb87cc67(DST MAC Address)
00183e0153d5(SRC MAC Address)
0800 (IPV4)
45 ({IP version, IHL})
00 ESCP, ECN (ignore these)
0528 (length of the entire packet including header,which = 1320 bytes since 1272 bytes of rtp payload + 20 bytes of rtp header + 8 bytes of udp header + 20 bytes of ip header)
aabb (Identification)
0000 (Flags,fragmentoffset)
4011 (TTL=64,protocol = 17 which is udp)
47b6 (Header Checksum)
c0a80102 (src ip address)
c0a80101 (dst ip address)
1234 (src port)
1234 (dst port)
0514 (length of udp packet = 1300 bytes)
0000 (udp hdr checksum)
801800000000000000000000000004f8001a0000 (20 byte RTP header)
//following is RTP payload (424 pixels)
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

Dealing with byte aligning was a tricky thing. It took a few builds to get that straight.