Codec Operating System Software

As mentioned previously, the Cisco TelePresence codec runs the Linux operating system on an embedded Compact Flash module. The Linux OS is highly customized and secured including only those functions and modules necessary for it to operate.

Management Interfaces

A shell interface (accessible only through SSH on the primary codec) runs on top of the underlying OS to give administrators the command-line interface (CLI) necessary to administer the system. The primary codec also runs a highly customized version of Tomcat web server, which provides a web-based alternative to the CLI administration interface. The CLI and the web-based interface collectively are referred to as Cisco TelePresence System Administration.

Figures 1 and 2 illustrate the CLI and web-based administration interfaces.

 

Figure 1: Cisco TelePresence System Administration CLI

 

Figure 2: Cisco TelePresence System Administration web interface

Compact Flash and Component Firmware

The Cisco TelePresence System Administration software comes as a signed binary archive image (.sbn file) and contains the operating system and all other software modules, including the firmware to be loaded into all its peripherals, the video and audio subsystems, cameras, displays and other components. The .sbn file is preloaded in the factory on the Compact Flash module and can be upgraded or downgraded by obtaining the desired version from Cisco.com and then loading that file on the Cisco Unified Communications Manager (CUCM) server.

When the system is powered on, or anytime it receives a restart command from the CUCM to which it is registered, the primary codec downloads its configuration from the CUCM. The configuration file, in turn, contains the filename of the software load that the system should be running (for example, the filename SIPTS.1-5-0-2000R.sbn), and if the current version running on the Compact Flash does not match the filename contained in the configuration file, the codec downloads the new file from the CUCM. The Compact Flash on the codec is divided into three partitions: a factory slot, slot 1, and slot 2. The new file is downloaded to either slot 1 or slot 2. If slot 1 is currently the active slot, the codec downloads the new image to slot 2. If slot 2 is currently active, the codec downloads the new image to slot 1 and then reloads itself to install the new image.

Upon booting up, the codec checks the firmware of the secondary codecs and syncs its Compact Flash slots with those of the secondary’s. The codec also checks the firmware of all the attached peripherals and compares their versions against the versions bundled within its running image. If any of them do not match, the codec pushes the new firmware to that peripheral.

Notice at the bottom of Figure 2 the Compact Flash contents of each of the three codecs is listed and which slot is currently the active slot on each codec. The System Details button on that page launches a new page that displays the firmware for every component attached to the system. This same information can be accessed through the CLI interface using the show upgrade detail command or by querying the correct SNMP MIB variables.

Component Status

The primary codec keeps track of all the components attached to it, including the secondary codecs, cameras, displays, document cameras, projectors, microphones, and so on. If any component is malfunctioning, an alarm status is displayed on the Administration web interface and can trigger SNMP trap notifications if configured with an SNMP trap destination. The state of the system and all its components can be viewed on-demand at any time through the web interface, CLI, or through SNMP MIB polling mechanisms.