The siemens 685IP has a built-in ATA, I had also assumed that was what the o/p was asking about, but i believe there is also a standard 685 model without the sip functionality.
edit: re-read original post. model is in fact 685IP. Irrelevant anyway as question has been answered - but for future reference and as the o/p found out first rule with sip devices is to always disable sip alg on your router.
O2 16M/1.3M - Virginmedia 50Mb
Edited by BipolarBear (Fri 22-Jan-10 23:07:41)