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Horizontal viewing is the angle between the audience's eyebrows and the ends of the screen in a horizontal direction.
The following figure shows the system information for a VP96 Series MCU . From this information, what conclusions can we infer from the following?
Video conference room integration refers to the end-to-end solution () that uses corresponding equipment to meet the user's requirements for various scenarios in the conference room in accordance with certain design principles in the construction of the conference room
The protocol can be used for public-private network traversal of devices that support the H.323 protocol. (Please fill in the type of agreement).
At present, the sampling method mainly used in video communication: 4:2:0 sampling method ().
The main advantages of AAC-LD audio encoding are: low bandwidth, low latency, and high quality. ()
At what level is the SIP protocol located?
NLOG supports viewing historical network data for event venues within the conference ().
What factors does the quality of digital audio depend on?
In the networking, in which stage of signaling transmission occurs, such as the transmission keep-alive duration, keep-alive port, and keep-alive fields?
Users can call a conference access number and then create a video conference based on the IVR prompts.
As can be seen from the figure, the venue can not receive remote venue video in the meeting, what measures can the user take to locate the cause of the failure?
SIP messages fall into two categories, messages and response messages.
Reducing reverberation time can be achieved by covering walls, ceilings, windows, and floors with soft finishing materials.
What are the correct items in the following description of the SIP protocol?
What are some of the following ways to create a video IVR meeting?
Which of the following protocol messages does Wireshark support decoding?
protocol for remote camera control ().
Dark-toned tablecloths are recommended to increase reflective astigmatism to keep attendees' faces (jaws) shiny.
The video signal starts from the input terminal equipment, is sent to the network after encoding and compression, and finally displays, and has gone through many image processing links in the middle, mainly including: IP camera signal acquisition, pre-processing, compression encoding, data packaging and transmission, decoding, image format changes, playback.
is a general multimedia communication control protocol, mainly for conference communication design, H.323 system using H.245 protocol as a control protocol, for the establishment, maintenance and release of control channels.
The () phenomenon occurs in a conference when the microphone is used at the same time as the speaker and the sound system emits sound that can be collected by the microphone.
Which of the following ways does HD terminal support to initiate peer-to-peer calls?
Which of the following is not a disadvantage of forward error correction?
In the figure, select an attribute of the packet, right-click and select the option within the ( ) group to specify this attribute as a filter condition, which must be clicked apply before it takes effect.
The following description of the standalone SC ride wall networking configuration, which one is wrong?
When the terminal enables the remote monitoring function, the user can remotely monitor the main video image or presentation image of the end in the Web interface, and can also take photos to save, but can not view the mainstream image or presentation image of the remote end.
The large amount of data and the existence of data redundancy in the sound signal are the basis for the encoding of digital audio.
Illuminance, expressed in terms of the luminous flux accepted per unit area, is expressed in lux (Lux , lx ). ( )
RTP is a real-time transmission control protocol: on multicast (multicast) or unicast (unicast) network services, provides end-to-end network transmission capabilities, suitable for applications to transmit real-time data, such as audio, video or simulation data.
The main roles of RTCP include ( ).
The MCU is in wall riding mode, ( ) needs to be registered with the GK.
Network recording supports downloading the recording file to the local area in ( ) format, and supports local playback.
931 Loaded on the ( ) layer.
Common SIP calls to the SDP negotiation process include ( ).
Under the static NAT networking, the packet of the private network terminal through the firewall will change, and the following description is wrong ( ).
According to H. 323t, the signaling required to complete the process of exchanging capabilities is. ( )
In video conferencing, the empty field noise is required not to be greater than ( ).
At the UDP layer, H.323 protocols fall into three broad categories, where the functions of the terminal control class are not included. ( )
Video conferencing requires a color rendering index greater than ( ) for light sources
The environment of the display area requires low illumination, and the reasons for the lower illumination required at the digital projection screen are ( ).
The default mode of operation for the GE1 port of the MCU is ( ).
The recording server saves the stream sent by the MCU at ( )o
In the RTP specification (RFC3550), a total of ( ) types of RTCP reports are defined to report current control information.
MP mainly completes those functions () later. (2 answers).
The following description of the H.323 call flow is correct
The following description of the cascading characteristics of the miniMCU is correct. () (3 answers).
The MCU wall-riding mode has its advantages, but there are also certain constraints, such as ( ).
Nlog v2.0 can export file formats including ( ).
Which of the following is not a disadvantage of forward error correction ().
The most fundamental difference between the human voice is ( ).
MSDR is the master-slave decision to reject the message, when the result of the ability to exchange is inconsistent with the settings on this end, then reply to the MSDR
Which of the following signaling messages are capable of exchanging?
On top of UDP, the H.323 protocol is divided into (). (3 answers).
The VP9650 MCU has a height of ( )U , with a total of ( ) slots.
Loudness indicates the strength of the sound, ( ) determines the size of the loudness.
The compression encoding of audio signals can be divided into ( ).
Which of the following belongs to the extension request (). (3 answers).
By default, the terminal reports the packet loss rate to the MCU once per ( ).
Regarding the Client proxy in the H.460 protocol, the following description is correct ( ).
Master-slave decisions are mainly used to prevent both parties from triggering the same unsharable event or resource at the same time during communication, so a master party needs to be identified in
advance. When a conflict occurs, the slave shall act at the discretion of the master.
The function of the redirect server is to map the addresses in the request to zero or more new addresses, which are returned to the client.
Forward Error Correction FEC enables super error correction when more than 0.1% of the media stream drops within 10S are detected after the two parties have established a call. The super error
correction function will divide the call bandwidth into a part and use it to transmit redundant code streams that are anti-packet loss.
RTP is a real-time transmission control protocol: on a network service of multicast (multicast) or unicast (unicast). Provides end-to-end network transmission capabilities for applications to transmit real-time
data such as audio, video or simulation data.
Peer-to-peer calls between endpoints must use an MCU, but multipoint meetings can be scheduled without an MCU.
Request/response messages on reliable transports are not retransmitted.
In the camera control of the WEB interface, only the local camera can be controlled, not the remote camera. ( )
The H460 protocol specifies that the H.323 media streaming portion of the public-private network traversal processing process is
The chamber sound reaches a stable state during reverberation time, and the residual sound is repeatedly absorbed by the sound absorbing material in the room after the sound stops, and the original value
of the average sound energy density word decays to one part in a million (Acoustic code attenuation 60dB). The time required, expressed in T60.
When sending and receiving T.140 subtitles, both parties who need to join support T.140 subtitles.
The SIP protocol is the session initiation protocol for establishing, controlling, and releasing sessions. ( )
Remote audio loopback, from audio input, encoding, transmission through the network to the remote end and then forwarded back, the main test network connection is normal.
The terminal auxiliary IP is designed so that users can log in to the terminal configuration or debugging in the LAN, which can be used for main business. ( )
The gatekeeper's address translation function refers to the conversion of farm names or numbers to IP addresses based on the data table at the time of node registration.
Illuminance is based on the luminous flux received by the vertical surface as the standard, and if oblique illumination is used, the illuminance decreases. ( )
The key point of signaling packet analysis is to be familiar with the flow of signaling, and when problems are found, focus on which signaling packages should be in the signaling process, and filter irrelevant
data. The grab packet didn't catch which messages should have. ( )
If both the sender and receiver () are the same, the MCU forwards directly. (3 answers).
Background tones take complementary colors of skin tones, avoid large areas of skin color proximity or similar colors; Generally use blue, gray, blue-gray combination and other shades; The background
image of the large line uses the simplicity and clarity of the picture.
The Call-ID header field serves as a unique identifier for a collection of messages, and in a conversation, the Call-id must be the same in all the last requests sent by each UA. ( )
Color temperature affects the white balance of the camera, and where the color temperature is complex, the image can be cast.
Due to the size of the display and the limitation of MCU resources, the number of multi-screen sprites generally does not exceed 16 sprites, otherwise the image is too small and the picture will not be clear.
H.323 is used to provide multimedia services in packet-switched networks. ( )
The role of RTP in VoIP mainly includes: real-time transmission of media information, elimination of jitter, card performance, prevention of packet loss, in a certain situation can be transmitted DTMF signals,
tones and signaling.
Speech enhancement technology Jitter Buffer is the use of a human intervention signal wave, to eliminate the echo signal generated during the communication process, while retaining other normal voice
signals, in order to achieve the normal communication Use. ( )
Any SIP message consists of a starting line, a header field, and a message body, and the header domain must end with CFLF (Carriage Return Line Feed).
Cascading between MiniMCU, the default caller will be the primary MCU and the MiniMC that is already the primary MCU will be called It will not be changed again during the meeting. ( )
Several video compression standards that are currently widely used include: H.261H.263 and H.264 and MPEG-1. MPEG-2 and MPEG-4. Its H.26X series of standards is primarily used for real-time video
communications, and the MPEG series of standards is primarily used for video storage (DVD), video broadcasting, and video streaming.
Network recording and broadcasting does not occupy any resources of the MCU, and there is no interference with the running status of the video conference.
The role of the RTP protocol is ( ). (Fill in the blanks)