Anseem,

the secure logical channel does not have its own data type. It is merely an abstract notion telling that the OLC operates in a certain mode. It is flagged by KeyProtectionMethod.secureChannel.

The security logical channel is a separate security connection parallel to the unprotected OLC; e.g., TLS, SSL,... The security logical channel is used to establish authentication and exchange key material. This key material is used by the master then as a key encryption key for secure transmission of the media key (within the OLC).

I'm currently preparing an updated version of H.235v2, that will be presented at the upcoming Rapporteurs meeting in October.

Regards,

Martin.

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-----Original Message----- From: Aseem Agarwal [SMTP:aseem@TRILLIUM.COM] Sent: Friday, September 17, 1999 2:54 AM To: ITU-SG16@mailbag.cps.intel.com Subject: H.235 Control Channel

Hi All H.235 specifies opening up a secure logical channel. In this mode of operation the regular H.245 control channel may operate in unsecured mode. I have the following doubts about this procedure:

1. What is the "DataType" value used in the OpenLogicalChannel message exchanged for the secure channel ?

Section 8.2 specifies that "encryptionData" may be used, but elsewhere in the document the channel is referred with the value "h235Control" which is yet another value for dataType.

2. How does the exchange of encryption related information happen on the secure logical channel ? Does this happen in the data plane ? OR this new logical channel serves as a new control channel and the key exchange happens using EncryptionUpdate messages ?

H.235 does not clearly specify the sematics/functionality of this logical channel. IMHO, many loose ends have been left behind which may result in different implementations.

Comments/feedback welcome. Also, please let me know when we can expect the updated/next version of H.235 document.

Regards, aseem@trillium.com