Cisco Unified IP Phone Firmware Distribution Methods
Source: Cisco Systems
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.