Snom 100 v1.5 User Manual page 59

Make sure that BOOTP and DHCP are activated in case
you want to utilize them.
BOOTP is similar to DHCP only useful for the
administration of larger networks. It is only needed
when the administrator want to avoid setting the TFTP
addresses manually on each phone.
Windows does not offer a TFTP-Server. It has to be
obtained from another provider to make a flash
update possible on a Windows system.
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