1. AES Encryption

2. Page 2 AES Encryption Description Previous versions of Encryption were only available between Zultys phones. Version 3.0 adds encryption between the phone and the MX. This ensures that calls to the PSTN are encrypted to the edge of the IP network. Encrypted calls can be terminated on an AA or even the VM server.

3. Page 3 Call Scenarios When calling the PSTN – The call can be encrypted between the phone and the MX When calling another ZIP phone and the call goes to Voicemail – This call can be encrypted. The saved voicemail will be recorded unencrypted. When calling the PSTN and recording the call – This is a feature that is currently not enabled. When calling through an ITSP – These calls cannot be encrypted as the MX will not terminate the RTP stream (Unless the ITSP uses an MX!). When a call goes over ALG to an ITSP that is being recorded – This call cannot be encrypted – see above.

4. Page 4 Capacity The total number of calls that can be encrypted phone to phone is unlimited – since it is the phones that are doing the encryption / decryption process. The total number of simultaneous calls that can be encrypted to the PSTN is 60 on an MX250 and 10 on an MX30.