Partially. You will be able to establish a connection, and the Z/IP ONE will decode audio from the Zephyr Xstream, but the Xstream will not decode audio from the Z/IP. If you still wish to do this, you’ll need to place your Zephyr Xstream in the “SIP” interface mode (see the Codec menu for this setting). Set your Xstream’s encode/decode mode to AAC, preferably 128 kbps mono or stereo. On the Z/IP ONE side, set it for MP2-AAC coding. Note that this procedure will only work if your Z/IP ONE is NOT registered with a SIP server, since the Zephyr Xstream is not SIP capable and will not receive calls routed through SIP servers.