Hello. I have configured a Siemens OpenStage 15 SIP phone on the Mitel 3300 server via the Multiline IP sets form using SIP. Internal calls from the Siemens SIP phone to other Mitel IP phones work. However, when making an outgoing call from the Siemens SIP phone, once the call is established, both parties in the call cannot hear each other. Outgoing calls are made via a PRI interface to the PSTN. The Mitel 3300 server is not configured to make outgoing calls using SIP. So was wondering if it is still possible to make external calls via the 3300 with a Siemens SIP phone by adding some other configuration.
