The basestation does not store any contacts - these are held in the handsets. See page 157 of the manual regarding the use of .vcf files.
Thanks for the manual. Transfer seems a straightforward process. I've since found a
Gigaset Utility 'Quiksync' - Mac and Windows, which appears to do the transfer automatically. I assume that putting contacts in one handset would cascade through all linked to the same base station.
Page 104 of the manual gives info about the ring delay settings for the answering machine
Found that. Very helpful.
As an aside I did try the Voipon site for a manual for the Yealink W73P but I get either a 'cannot access' message or a quickstart guide which tells you very little.
iDNet provide a Yealink system with their voip offering so that would be an alternative, but there seems little to no information on transferring contacts. Possibly they assume that users will opt for a networked server