Rtp Packet; Rtcp Packet - 3Com MSR 50 Series Configuration Manual

The header of HTTP response message consists of status line and header. The
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status line consists of the HTTP version, a space, a status code, a space, a status
phrase.
Headers of request message and response message both consist of several
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optional fields. The response message header contains HOST field, which is
used to identify the host name and port number of server. The header of the
message with body load contains Content-Type field to identify the MIME type
of body load.
When the length of an HTTP message with body load exceeds the maximum
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segment size (MSS) of TCP, the message is split.

RTP Packet

RTP (Real-time Transport Protocol) packet is in the load of UDP packet. A UDP
packet carries only one RTP packet.
See Figure 482
Figure 482 RTP packet format
0 2 3 4
V P X
The fields are described as follows:
V: 2 bits, version number.
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P: 1 bit, padding flag.
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X: 1 bit, packet header extension flag.
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CC: 4 bits, contributing source number flag.
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M: 1 bit, special event flag.
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PT: 7 bits, payload type flag.
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sequence number: 16 bits, data packet sequence number.
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timestamp: 32 bits, time stamp.
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SSRC: 32 bits, synchronization source, synchronization source flag.
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CSRC LIST: 32 bits, contributing source, contributing source flag list. The
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number of the contributing source flags depends on the value of the CC field.
It can be up to 15.
Payload: Packet payload.
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RTCP Packet

The RTCP packet is in the load of UDP packet. A UDP packet carries at least two
RTCP packets, called compound RTCP packet.
See Figure 483
for RTP packet format.
8 9
CC M PT
Time Stamp
CSRC identifiers
for RTCP packet format.
15 16
Sequence Number
SSRC
Payload
DAR Overview 1701
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