Direct IP calling allows two parties, that is, a Handset and another VoIP Device, to talk to each other in an ad-hoc fashion without a SIP proxy.
Elements necessary to complete a Direct IP Call:
Both DP715 and other VoIP Device, have public IP addresses, or
Both DP715 and other VoIP Device are on the same LAN using private IP addresses, or
Both DP715 and other VoIP Device can be connected through a router using public or private IP addresses (with necessary port forwarding or DMZ).
DP715 supports two ways to make Direct IP Calling:

Using IVR

Pick up the Handset then access the voice menu prompt by dial “***”
Dial “47” to access the direct IP call menu
Enter the IP address after the dial tone and voice prompt “Direct IP Calling”
Using Star Code

Pick up the Handset and then dial “*47”
Enter the target IP address.
Note: NO dial tone will be played between step 1 and 2.

Examples of Direct IP Calls:

a) If the target IP address is 192.168.0.160, the dialing convention is *47 or Voice Prompt with option 47, then 192*168*0*160 followed by pressing the “#” key if it is configured as a send key or wait 4 seconds. In this case, the default destination port 5060 is used if no port is specified.

b) If the target IP address/port is 192.168.1.20:5062, then the dialing convention would be: *47 or Voice Prompt with option 47, then 192*168*0*160*5062 followed by pressing the “#” key if it is configured as a send key or wait for 4 seconds.
Note: When completing direct IP call, the “Use Random Port” should set to “NO”.

The Handset can be registered to 4 different DP715 base stations; however the DP715 can only receive/make calls using a specific DP715 Base station. User may choose the Handset registration to be manual or automatic. If user selects the manual mode, user needs to select which Base station he wishes to use.
If the user selects the automatic mode, the Handset will be able to make/receive calls using the latest Base station it registered to, if the handset looses the coverage of the active Base station it will start searching for any other available Base Station it was previously registered to.

If distinctive ringtone is needed for some specific call, the user can add the specified contact in their phonebook and specify the ringtone of their choice.

All the registered handset to the DP715 base station may use the same SIP Account and share it across all the handset, the users need to use Hunt group feature to allow this scenario, the DP715 offer different hunt group option to manage the incoming calls depending on his needs:

Linear, parallel and Shared line.
Linear Style will sort the call to the lowest-numbered available line; this is also called “serial hunting”.
Parallel Style will ring all the handsets on incoming calls.
Shared line Style will ring all the handsets on incoming calls, any handset member of the same hunt group that try to dial out while there is an ongoing call it will be automatically conference in the ongoing call.

The DP715/710 Handset does not have a dedicated MWI icon, user are notify of the message waiting by stutter tone once the handset goes off-hook.

Besides using the config tool and config template to generate the config file, users could also provision the DP715 using XML format file. Users will need to create an XML file cfgxxxxxxxxxxxx.xml (where xxxxxxxxxxxx is the MAC address of the phone) using the P values in the config template. For the XML example configuration file, please refer to the document in the link below:
Provisioning guide

The users may obtain the DP715 Base station IP address, by accessing the IVR from any registered handset to the base station.
In order to access the IVR use any Handset registered to the DP715 base station and dial *** this will get you into the IVR, dial 02 and the DP715 Base Station IP address will be prompted.

This function is applicable using the Handset for VoIP calls only. Assume that parties A and B are in conversation. Party A wants to Attend Transfer B to C:

A presses RECALL on the Handset for dial tone.
A then dials Caller C’s number followed by # (or wait for 4 seconds).
If C answers the call, A and C are in conversation. Then A can hang up to complete transfer.
If C does not answer the call, A can press “flash” to resume call with Caller B.
Note: When Attended Transfer fails and A hangs up, the DP715 will ring back user A to remind A that B is still on the call. A can pick up the phone to resume conversation with B.

The DP715 support up to 4 simultaneous calls.

Make sure that you haven’t reached the max allow handsets per Base station, access to the device web GUI and make sure from the status page that the DP715 base station has not reached the maximum of 5 allowed Handset.

The supported languages are as follows:
English, French, German, Spanish, Dutch, Italian, Czech, Danish, Greek, Norwegian, Polish, Portuguese, Russian, Swedish, Turkish.