Since a couple of days I using an Asterisk server. I noticed something obvious to anybody dealing with telephony since any longer time than myself; echo is nasty... Is it correct to say that the difference between a conversation between SIP phone, Asterisk, an ISDN BRI line and a GSM phone is entirely digital, whereas I do have a remote analog portion of the sound link only if I dial an analog landline subscriber? At times I do hear a bad echo of my own voice when calling old POTS users (while they do not report any echo), while so far I did not have any echo with cellphones. Can I do anything with echo suppression on my side? Is it beyond the features of my cheap (convenient..) Fritz PCI card? Thanks, Aldo