Updating phone loads in 2811
Keep in mind that maximize router DRAM and flash memory size before IOS image upgrade is always a good idea to make sure the router can fit the IOS image file and can run any IOS image version.
When they are booting up, the phones attempt to upgrade via TFTP to the current firmware specified in CUCM, but they fail and display "Auth Fail" on their screen.
Octo WS2811 requires the DMA (Direct Memory Access) engine which is available only in Teensy 3.0 and Teensy 3.1. Please use caution when viewing large numbers of LEDs at close distance. AC mains voltage should be wired properly according to electrical codes. Fewer or shorter strips may be used, with addressing described below. Early versions of Octo WS2811 required pins 15 & 16 to be connected together. Approximately 1000 LEDs per Teensy 3.0 or 4000 LEDs per Teensy 3.2 are recommended for large LED projects, to maintain high performance.
A diffusing material in front the LEDs is usually a good idea. Octo WS2811 uses internally uses a timer, and a PWM waveform at a pin on some boards. Any number of Teensy boards may be used to support large LED arrays. The display update continues, taking 30 microseconds for for each LED, plus 50 microseconds to reset the WS2811. The Basic Test is useful to verify your LEDs work, and to find the correct color configuration. If yours have different wiring, the colors will appear in a different order.
Later description will show you how to back up the image* There is a chance that a router loses power or loses connection during the IOS image transfer (copy from or to server) which may cause the router to have no working IOS image to boot up from. Try the following* Backup image to TFTP server * Download image from TFTP server For those routers or switches that have USB port, you can use USB Flash drive to backup or to download IOS images as follows* Backup image to USB Flash drive * Download image from USB Flash drive Once you have both old and new IOS images in USB Flash drive, you can either save copies to your computer or to some storage such as DVD, tape backups, or some FTP servers.
When such incident happens, you will be glad that you first back up the IOS image to server before deleting working IOS image off the flash memory. To transfer an IOS from PC to ROUTER, the following conditions must meet* The new IOS image file is in working condition since corrupted IOS image won't do any good* The new IOS image file is inline with the router DRAM and flash memory size.