Goog found this: http://enterprise.huawei.com/ilink/enenterprise/download/HW_U_149094 which says: ,----< excerpt from HW_U_149094.pdf ยง35.3 > | Huawei NGN Cipher Version1 (HNC1) is a patented algorithm of Huawei | and supports the 122/256-bit key. In encryption, the softswitch | (SoftX3000) of Huawei is required to cooperate. Currently, HNC1 is | used in the application scenarios in which the UA5000 works with the | SoftX3000. `---- It also says that those two products encrypt the rfc2833 traffic with that algorithm, w/o implying that it is part of 2833. As for why it is useful to encrypt the 2833 w/o also encrypting the voice, I can only speculate. Perhaps some idiosyncrasy of PRC law? Or to provide better integrity? -JimC -- James Cloos <cloos@jhcloos.com> OpenPGP: 1024D/ED7DAEA6