Though the problem is H.323

Well, I feel the base of TCP/IP more than saying as for "H.323" though today's chief telecommunications engineer's material is H.323. It neatly examines if it is not good around here because it is knowledge that the problem of the voice coding is not limited to H.323 this time and the protocol of the voice call makes indispensable, it acquires, it sleeps, and, then, today's material is [kochira] ↓↓.



- Recommendations such as encoding of voice in Internet protocol telephone in accordance with ITU-T recommendation H.323 and making to packet and protocols



In one of the encoding methods of the voice, there is an encoding method by PCM with the transmission speed of 64Kbit/s provided for by ITU-T recommendation G and 711.

These sentences are correct.
- There is μ-LAW or a-LAW in G.711, both are encoded by eight bits, and the transmission speed is 64Kbit/s.
- Signal vs. warp performance of μ-law in a low-level signal is higher than that of A-law.
- The dynamic range of A-law is wider than that of μ-law.
- The μ-law adoption nations will be doing conversion from μ to A use A-law in an international connection.



The voice packet of the Internet protocol telephone is transmitted by using not TCP but UDP as a protocol in the transport layer because real time is demanded, and using RTP as a high-ranking protocol in the transport layer.

These sentences are correct.
- Real time is UDP+RTP if said.



When the delivery confirmation of the IP packet is done, and it is not possible to transmit, it sends it again in UDP though the transmittal confirmation of the IP packet is not done in TCP.

These sentences are wrong.

- TCP is ♪ three way handshaking that does the delivery confirmation.



RTP has the function of the annulment of the packet with a large delay etc. in the protocol to send the real-time data in the voice and animation, etc.

These sentences are correct.
- RTP annuls the packet with a large delay.



Well, how?
Apart from three sentences in the latter half
Do not it be easy remember considerably and does not fight hard against the first G.711?
When easily introducing it

G.711（PCM）・・・IP net in telephone network and enterprise chiefly
G.726（ADPCM）・・・PHS etc. for the main.
G.723.1(ACELP）・・・IP net in enterprise Internet phone/chiefly
G.729（CS-ACELP）・・・IP net in cellular phone and enterprise chiefly
G.722（SB-ADPCM） ・・・IP net in enterprise chiefly



Is it such feeling in the main point?
It easily thinks information around here to obtain fully when googling and seeing and examine it once, please.
Then, around here today