Dear Mr. Okubo, Mr Harasaki, and other Q.12/16 experts,
Attached please find some comments regarding open logical channel and Section_8_rev.mw6.
Best regards,
Li Yan **************************************************************** Lucent Technologies Phone: 732-957-3877 2E-433, 200 Laurel Ave., Fax: 732-957-5627 Middletown, NJ, 07733 E-amil:lyan@lucent.com U.S.A. ****************************************************************
1. Open logical channels for the 1st terminal, 2nd terminal, etc.
SO> One point I need your views is the way to open logical channels. In SO> Section 8.3.1 (first terminal added to the conference), the text SO> reads As follows:
SO> "After establishment of the additional VC(s), the procedures of SO> H.245 shall be used to open the desired video, audio, data, and/or SO> control logical channels using logical channel signaling protocol SO> and bi-directional logical channel signaling protocol defined in SO> H.245."
SO> In Sections 8.3.2 (second terminal added to the conference) and SO> 8.3.3 (third terminal added to the conference), however, it reads as SO> follows:
SO> "An MCU shall open the desired video, audio, data, and/or control SO> logical channels using the logical channel signaling protocol and SO> bi-directional logical channel signaling protocol defined in H.245."
SO> The difference is intentional? If uni-directional logical channel SO> Signaling is used, not only MCU but also the terminal should SO> establish the logical channel, otherwise we cannot have SO> bi-directional video transmission, for example. If all logical SO> channels are bi-directional, then there is a reason for MCU to open SO> them because it is the master. Note that H.310 strongly recommends SO> to use the bi-directional logical channel signaling if the media is SO> bi-directional.
SO> The first description is applicable to all the cases, while the SO> second description may be more appropriate to the current multipoint SO> case. In the latter case, we need to add some language that the SO> logical channels should always be bi-directional.
SO> Any thoughts?
My original text was focus only on tightly coupled MCU ( VC connection configuration a)), where bi-directional logical channels are always used for all the terminals connected to MCU. Now, since we want the procedures to cover other connection configurations, such as in Figure 2, b), c), and d), your changes to use the first description to replace others are more proper.
2. Can we change the "under working" in 8.5.2, 8.6, and exceptional procedures to "For further study"?