Cisco Unified IP Phone Firmware Distribution Methods
When Cisco started selling the Cisco IP Phone 7940 and 7960 models, the firmware needed to run the phones was relatively small (less than 1 MB). Because updated phone models with enhanced features are now available and it is possible to centralize the call-processing servers, the method by which firmware is upgraded on a phone has become increasingly more important. Over a high-bandwidth LAN environment, the download process and duration are limited by how quickly the phone can consume the downloaded file. But when downloading new firmware over a low-bandwidth link, the process is limited by the size and latency of the data pipe between the firmware server and the upgrading phone.