The name “Gigaset” is associated with Siemens – this was the brand Siemens had used for a long time for their phones. However Gigaset became an independent company which produces phones and accessories under this name in license. Also see http://www.gigaset.de.
Beginning of 2011 I’ve purchased a Gigaset S790 as replacement for my old phone. This model is also available with an integrated answering machine as S795 or as ISDN version under the name SX790 or SX795.
(Please see the German version for more details)