Configuring the Device Security Mode

After you have configured the Cisco CallManager for mixed mode using the CTL Client and the Cisco IP Phones have certificates, you must configure the IP Phones to support authenticated or encrypted calls. You can use the device security mode to configure a Cisco IP Phone for one of three security modes:

• Non Secure The IP Phone will not support authenticated or encrypted calls.
• Authenticated The IP Phone will support authenticated calls.
• Encrypted The IP Phone will support encrypted calls.

The default device security mode is configured in the Cisco CallManager Enterprise Parameters window; choose Cisco CallManager Administration > System > Enterprise Parameters. The default mode is Non Secure.

In addition to setting the default value, you can configure each individual IP Phone with the device security mode. Choose Cisco CallManager Administration > Device > Phone to display the Phone Configuration window, as shown in Figure 27-8. The default mode is Use System Default.

Figure 27-8. Configuring IP Phone Security Options

Note

In several situations, you should not use cryptographic services for Cisco IP Phones at all. With some Cisco IP Contact Center (IPCC) applications, for instance, cleartext signaling messages or media packets have to be seen by other devices (for instance, attached PCs). Another example is the use of Network Address Translation (NAT) or Port Address Translation (PAT). Because the translating device has to see cleartext signaling messages to be able to dynamically allow the negotiated UDP ports that will be used for Real-Time Transport Protocol (RTP), encryption cannot be used.