Cisco 7962G Administration Guide - Page 25

Chapter 1 An Overview of the Cisco Unified IP Phone Understanding Security Features for Cisco Unified IP Phones Table 1-3 Overview of Security Features Feature Image authentication Customer-site certificate installation Device authentication File authentication Signaling Authentication Manufacturing installed certificate Secure SRST reference (SCCP phones only) Media encryption Signaling encryption CAPF (Certificate Authority Proxy Function) Description Signed binary files (with the extension .sgn) prevent tampering with the firmware image before it is loaded on a phone. Tampering with the image causes a phone to fail the authentication process and reject the new image. Each Cisco Unified IP Phone requires a unique certificate for device authentication. Phones include a manufacturing installed certificate (MIC), but for additional security, you can specify in Cisco Unified Communications Manager Administration that a certificate be installed by using the Certificate Authority Proxy Function (CAPF). Alternatively, you can install a Locally Significant Certificate (LSC) from the Security Configuration menu on the phone. See the "Configuring Security on the Cisco Unified IP Phone" section on page 3-14 for more information. Occurs between the Cisco Unified Communications Manager server and the phone when each entity accepts the certificate of the other entity. Determines whether a secure connection between the phone and a Cisco Unified Communications Manager should occur; and, if necessary, creates a secure signaling path between the entities by using TLS protocol. Cisco Unified Communications Manager will not register phones unless they can be authenticated by the Cisco Unified Communications Manager. Validates digitally signed files that the phone downloads. The phone validates the signature to make sure that file tampering did not occur after the file creation. Files that fail authentication are not written to Flash memory on the phone. The phone rejects such files without further processing. Uses the TLS protocol to validate that no tampering has occurred to signaling packets during transmission. Each Cisco Unified IP Phone contains a unique manufacturing installed certificate (MIC), which is used for device authentication. The MIC is a permanent unique proof of identity for the phone, and allows Cisco Unified Communications Manager to authenticate the phone. After you configure a SRST reference for security and then reset the dependent devices in Cisco Unified Communications Manager Administration, the TFTP server adds the SRST certificate to the phone cnf.xml file and sends the file to the phone. A secure phone then uses a TLS connection to interact with the SRST-enabled router. Uses SRTP to ensure that the media streams between supported devices proves secure and that only the intended device receives and reads the data. Includes creating a media master key pair for the devices, delivering the keys to the devices, and securing the delivery of the keys while the keys are in transport. Ensures that all SCCP signaling messages that are sent between the device and the Cisco Unified Communications Manager server are encrypted. Implements parts of the certificate generation procedure that are too processing-intensive for the phone, and it interacts with the phone for key generation and certificate installation. The CAPF can be configured to request certificates from customer-specified certificate authorities on behalf of the phone, or it can be configured to generate certificates locally. OL-14625-01 Cisco Unified IP Phone 7962G and 7942G Administration Guide for Cisco Unified Communications Manager 6.1 1-11