Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:00,240 --> 00:00:07,590
Information may be segmented or broken up into smaller chunks or transmission across a physical medium
2
00:00:08,010 --> 00:00:15,040
the maximum transmission unit or empty you of an outgoing interface depends on the physical medium.
3
00:00:15,090 --> 00:00:20,640
As an example they empty you of fust Ethan It is 5400 bytes.
4
00:00:20,850 --> 00:00:28,650
However TZP can theoretically support sixty five thousand four hundred ninety five bytes in a single
5
00:00:28,650 --> 00:00:29,380
packet.
6
00:00:29,460 --> 00:00:35,370
When that is sent to the lower layers of the ozone model that will need to be broken up into fragments
7
00:00:35,560 --> 00:00:42,330
for transmission across the physical medium which for example only supports 50 or 100 bytes.
8
00:00:42,330 --> 00:00:49,890
Data is therefore broken up into smaller chunks and the receiver using TZP will need to put those fragments
9
00:00:49,890 --> 00:00:51,180
back together again.
10
00:00:51,510 --> 00:00:58,950
The maximum segment size or MSA is is the largest amount of data in bytes that TZP is willing to send
11
00:00:58,950 --> 00:01:02,010
in a single segment for best performance.
12
00:01:02,010 --> 00:01:08,700
The MSA is small enough to avoid Arpey fragmentation which can lead to excessive retransmissions if
13
00:01:08,700 --> 00:01:15,550
there's packet loss DCP support something called Maximum segment size and pause.
14
00:01:15,600 --> 00:01:23,400
MT You discovery or Porth maximum transmission unit discovery with the sender and the receiver can automatically
15
00:01:23,400 --> 00:01:31,260
determine what the maximum transmission unit is on a path between them and TZP will only put enough
16
00:01:31,260 --> 00:01:39,840
data into a single packet that fits that empty thus avoiding fragmentation of packets and thus avoiding
17
00:01:39,840 --> 00:01:46,620
the overhead associated with fragmentation and the putting together of the IP fragments off into you
18
00:01:46,620 --> 00:01:55,440
discovery is optional in IP version 4 that has now become mandatory in IP version 6 because of the efficiencies
19
00:01:55,860 --> 00:02:02,820
that it brings to the TZP transmission and the fact that IP version 6 does not support fragmentation
20
00:02:03,420 --> 00:02:12,190
on routers along the path between two hosts UDP does not support this and requires higher level protocols
21
00:02:12,550 --> 00:02:22,000
to sort out the fragments flow control GCP uses end to end flow control to avoid having the sender send
22
00:02:22,000 --> 00:02:27,370
data too quickly for the receiver to receive it and process it reliably.
23
00:02:27,580 --> 00:02:33,700
If the same the transmits data faster than the receiver can handle the receiver will drop the data which
24
00:02:33,700 --> 00:02:40,780
will require a retransmission retransmissions will waste time and network resources which is why most
25
00:02:40,780 --> 00:02:49,410
flow control mechanisms try to maximize the transfer raped while minimizing the requirements to retransmit.
26
00:02:49,470 --> 00:02:57,930
You may as an example have a PC with a powerful you sending data to a handheld PDA which can only process
27
00:02:57,930 --> 00:03:00,400
data at a much lower rate.
28
00:03:00,420 --> 00:03:07,710
The PDA should therefore regulate the data flow so its not overwhelmed in TZP basic flow control is
29
00:03:07,710 --> 00:03:15,400
implemented by acknowledgements from the receiver in receipt of data transmitted EECP uses something
30
00:03:15,400 --> 00:03:19,440
called a sliding window to control the flow of data.
31
00:03:19,530 --> 00:03:25,810
Windowing will allow the receiving computer to advertise how much data is able to receive before transmitting
32
00:03:25,810 --> 00:03:28,330
an acknowledgement to the sending computer.
33
00:03:28,780 --> 00:03:34,720
In each TZP segment the receiver will specify in the receive window field.
34
00:03:34,870 --> 00:03:41,200
The amount of additional received data in bytes that it is willing to buffer for the connection the
35
00:03:41,200 --> 00:03:48,400
sending host can only send up to that amount of data before it Miss White when acknowledgment and window
36
00:03:48,400 --> 00:03:54,610
size update from the receiving host UDP does not implement flow control.
37
00:03:55,520 --> 00:04:02,090
And in a VOIP environment as an example which uses UDP even though there's no physical connection between
38
00:04:02,090 --> 00:04:08,990
two handsets involved in a telephone call the call will stay up and the sender will merrily continue
39
00:04:08,990 --> 00:04:11,010
sending huge amounts of data.
40
00:04:11,180 --> 00:04:18,770
Even though the receiver cannot process the received data UDP relies on Hi-Lo protocols to implement
41
00:04:18,770 --> 00:04:20,280
flow control.
42
00:04:20,480 --> 00:04:28,850
Once again TZP is connection orientated and UDP is connection less TZP will establish the connection
43
00:04:29,300 --> 00:04:33,080
and maintain the connection during the entire transmission.
44
00:04:33,080 --> 00:04:37,220
Once the transmission is complete the session is terminated.
45
00:04:37,280 --> 00:04:43,610
UDP does not set up sessions and will just send the data in the hope that the receiver will receive
46
00:04:43,610 --> 00:04:43,980
it.
47
00:04:45,180 --> 00:04:52,770
Once again TZP implements reliability where every segment transmitted is acknowledged and if the segment
48
00:04:52,770 --> 00:04:59,070
went missing it is retransmitted UDP does not implement reliability.
49
00:04:59,220 --> 00:05:07,890
And once again relies on Hailo protocols to implement any reliability if required in certain cases such
50
00:05:07,890 --> 00:05:12,940
as voice over IP or video transmitted over an IP infrastructure.
51
00:05:13,140 --> 00:05:15,550
Reliability is not required.
52
00:05:15,600 --> 00:05:25,910
There is no point retransmitting last voice packets so a quick comparison between UDP and TZP or a reliable
53
00:05:25,910 --> 00:05:33,870
protocol and a best effort or unreliable protocol TZP once again is connection orientated.
54
00:05:34,120 --> 00:05:41,440
No data is transmitted before a session is established a three way handshake takes place before any
55
00:05:41,440 --> 00:05:42,930
data is transmitted.
56
00:05:42,940 --> 00:05:49,130
There are acknowledgements of data received and sequence numbers to track transmission of data.
57
00:05:49,510 --> 00:05:56,850
UDP on the other hand is connection less and does not track data and does not ensure delivery of data.
58
00:05:57,850 --> 00:06:00,080
TCAP is a sequence of numbers.
59
00:06:00,190 --> 00:06:12,190
UDP does not applications that use TZP include HGP email and FGP applications that use UDP include voice
60
00:06:12,190 --> 00:06:18,370
streaming applications like voice over IP and video streaming applications because of the nature of
61
00:06:18,370 --> 00:06:20,400
VoIP or video.
62
00:06:20,530 --> 00:06:28,270
There is no reason to retransmit in a VOIP environment the talker will be required to repeat what they
63
00:06:28,270 --> 00:06:28,820
said.
64
00:06:28,840 --> 00:06:33,960
If the listener was unable to decipher what was communicated.
65
00:06:34,450 --> 00:06:41,890
If you've ever used Skype at times it may sound like the person speaking is under water or they sound
66
00:06:41,890 --> 00:06:45,570
more like a machine than the person you know speaking.
67
00:06:46,300 --> 00:06:52,240
But you may still be able to understand what they've said and thus even though data went missing the
68
00:06:52,240 --> 00:06:54,080
conversation can continue.
69
00:06:54,190 --> 00:07:01,580
Or if it gets bad enough you would ask the speaker to repeat what they said in a video streaming environment.
70
00:07:01,600 --> 00:07:08,020
You may notice that part of the image is not refresh properly but you're still able to follow what's
71
00:07:08,020 --> 00:07:13,990
happening in the video because of the time sensitive nature of voice and video.
72
00:07:14,050 --> 00:07:19,350
It is pointless retransmitting data and thus TZP is not used in these environments.
73
00:07:19,360 --> 00:07:24,780
UDP is used so UDP is a transport layer protocol.
74
00:07:24,810 --> 00:07:32,430
It resides at layer for when the model it provides applications with access to the network layer all
75
00:07:32,440 --> 00:07:38,390
layer 3 without the overhead over liability mechanisms as discussed.
76
00:07:38,390 --> 00:07:42,380
This is ideal for voice over IP or video applications.
77
00:07:42,530 --> 00:07:49,730
It's connection less where one way datagram the center destination without advance notification to the
78
00:07:49,730 --> 00:07:51,430
destination device.
79
00:07:51,500 --> 00:07:55,440
There is no communication before transmission of data.
80
00:07:55,820 --> 00:08:01,690
The data just arrives at the receiver and it's expected that the receiver handle that data.
81
00:08:02,030 --> 00:08:08,940
UDP is capable of providing very limited error checking the UDP datagram does include an optional check
82
00:08:08,940 --> 00:08:16,080
some value which the receiving device can use to test the integrity of the data the UDP header also
83
00:08:16,080 --> 00:08:23,490
includes a destination port number and if that datagram is directed to an active code on the receiving
84
00:08:23,490 --> 00:08:29,900
device a return message can be transmitted to indicate that that code is unreachable.
85
00:08:29,910 --> 00:08:32,830
I'm going to discuss port numbers in more detail in a moment.
86
00:08:33,090 --> 00:08:36,100
It's a very important concept to understand.
87
00:08:36,150 --> 00:08:39,170
UDP provides best if at delivery.
88
00:08:39,180 --> 00:08:47,160
There is no guarantee that data is delivered packets may be mis directed duplicated or lost on the way
89
00:08:47,160 --> 00:08:48,840
to the destination.
90
00:08:48,870 --> 00:08:57,970
There is no guarantee of receipt of protocols will need to implement reliability if required.
91
00:08:58,030 --> 00:09:01,600
They are also no data recovery features in UDP.
92
00:09:01,600 --> 00:09:07,800
Once again Hiler protocols will need to recover from last corrupted packets.
93
00:09:07,960 --> 00:09:17,440
TFT as an example has a built in mechanism to handle data loss and TFT P using UDP has its own bulled
94
00:09:17,530 --> 00:09:25,480
in sequencing and retransmission mechanisms as it cannot rely on UDP to implement reliability.
95
00:09:25,480 --> 00:09:27,650
The UDP head is very simple.
96
00:09:27,820 --> 00:09:35,810
It has a 16 bit source port number 16 but Port to destination number so the specified the port number
97
00:09:35,810 --> 00:09:40,780
used by the source and a port number used by the destination.
98
00:09:41,000 --> 00:09:47,500
It has a 16 bit ETP length field that specifies the length in bytes of the entire datagram.
99
00:09:47,510 --> 00:09:54,020
In other words the header and the data the minimum length for UDP datagram is 8 bytes because that's
100
00:09:54,020 --> 00:09:55,990
the length of the header.
101
00:09:56,030 --> 00:10:01,550
Theoretically the maximum size is sixty five thousand five hundred thirty five bytes.
102
00:10:01,740 --> 00:10:08,940
But IP version 4 will impose a maximum limit of sixty five thousand five hundred seven bytes.
103
00:10:09,080 --> 00:10:13,970
Optionally a UDP checksum can be used for error checking.
104
00:10:13,970 --> 00:10:19,150
This is optional an IP version 4 but is not optional an IP version 6.
12083
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.