A media crypto class specifies one or more media-crypto attributes. Using the media crypto classes function controls the secure calls passthrough.

View Media Media Crypto Classes

Select the Telephony > Media Crypto Classes subdirectory for the VX node and view contents at the Media Crypto Classes screen.

Add Media Classes

Insert a new line in the Media Crypto Classes screen, then double-click the line to present the Edit Media Crypto Class dialog box.

Modify Media Classes

Double-click on table line in the Media Crypto Classes screen to present the Edit Crypto Media Class dialog box.



Crypto Suite

Select a crypto suite from the dropdown menu. The options include AES*CM**128*HMC*SHAI*80 and AES*CM-128*HMAC*SHAI*32.

Window Size Hint

Specifies the window size hint for the far end.


Select the Encrypt check box to enable encryption.


Select the Authenticate check box to enable authentication.

Replay Protection

Select the Replay Protection check box to enable replay protection for received packets. This is not negotiated with the far end.


Enables Microsoft Scalable Secure Real-Time Transport Protocol

Master Key Life Time

Master Key Lifetime is always selected. Valid range is 2*1 to 2*48.

Key Life Time Value

Enter the key lifetime associated with the key identifier. If the lifetime is not selected the key never expires.

As number of Packets

Select to identify the master key value as the number of packets.

As power of 2

Select to identify the master key value as the power of 2.

Key Derivation Rate

Enter the key derivation rate for encrypt-key. Valid values are 0-24.
A value of 0 indicates no key derivation for the life of the session.

Key Identifier Length

Enter the master key identifier length. Valid range is 1-4