This Frequently Asked Questions (FAQ) document provides concise answers and guidance for using the Grandstream DECT phones (DP7xx). It is intended to assist administrators and users in resolving common issues and understanding key features.
Product Overview & Specifications
DP750 is the DECT base station, while DP720 is the handset.
G.711µ/a-law, G.723.1, G.729A/B, G.726-32, iLBC, G.722, OPUS, G.722.2/AMR-WB (special order), in-band and out-of-band DTMF (in audio, RFC2833, SIP INFO), VAD, CNG, PLC, and AJB.
The frequency bands supported are:
- 1880 – 1900 MHz (Europe), 1920 – 1930 MHz (US),
- 1910 – 1920 MHz (Brazil), 1786 – 1792 MHz (Korea),
- 1893 – 1906 MHz (Japan), 1880 – 1895 MHz (Taiwan)
Number of Channels: 10 (Europe), 5 (US, Brazil or Japan), 3 (Korea), 8 (Taiwan)
DP750 base station covers up to 50m (~165 feet) indoors and up to 300m (~1000 feet) in outdoor environments.
Up to 20-hour talk time, and up to 250-hour standby time when the batteries are fully charged.
The supported languages are: English, German, Spanish, French, Arabic, Hebrew, Italian, Russian, Dutch, Japanese, Polish, Czech, Chinese Simplified, Chinese Traditional, Korean, Portuguese, Slovakian, Serbian, Turkish.
The DP750 supports up to 5 simultaneous calls.
XML or LDAP Phonebook uploaded to the DP750 station supports up to 3000 contact entries.
We suggest 5 base stations for the US, Brazil, or Japan deployment, 10 bases for the EU deployment, 3 bases for Korea, and 8 bases for Taiwan deployment. Each base can register up to 5 handsets.
DP750 can register up to 5 different DP720 handsets.
DP720 can be registered with up to 4 different DP750 base stations.
Up to ten (10) distinct SIP accounts per system, and each DP720 handset may map to any SIP account(s), and each SIP account may map to any handset(s).
Setup & Registration
The user may obtain the DP750 base station IP address from any registered DP720 handset to the base station using keypad Menu → Status, and navigate down to view the IP address of the DP750.
Please follow the steps below to register the DP720 with the DP750:
- On the DP750 Base station, press and hold the Radio/Page button for 7 seconds until the Radio icon starts blinking to start the Subscription process. Or access the web UI, and press the Subscribe icon to Open Subscription.
- On DP720, press the Subscribe softkey if available on the main screen or access Menu → Settings → Registration → Register while the DP750 Radio icon is blinking. Note: “Subscribe” softkey appears only if DP720 is not registered to any DP750 base station.
- Select BaseX (X=1-4) corresponding to the desired base station DP750, then press Subscribe.
- The DP720 will search for nearby base stations and will display the RFPI code and base station name of the discovered DP750.
- Press Subscribe to pair with the displayed DP750.
- The DP720 will display Easy Pairing on the LCD and play an audible buzz when successful. Then it will return to the home screen, displaying the handset name and number assigned by the registered base station.
The handset can be registered to 4 different DP750 base stations. Considering DP720 is previously registered to an initial base station, please follow the steps below to register a handset to an additional base station:
- Press Menu (left softkey or the selection key) to bring up the operation menu.
- Use arrow keys to reach Settings and navigate to Registration.
- Select Register and navigate to an unsubscribed base using the arrow keys, and click on Subscribe.
- Make sure that the subscription is opened on the new base station.
Note: User needs to switch the registration from one base to another using the DP720 keypad Menu → Settings → Registration → Select Base to select which base station he wishes to use.
- Make sure that you haven’t reached the maximum allowed handsets per base station, access to the device web GUI, and make sure from the status page that the DP750 base station has not reached the maximum of 5 allowed handsets.
- Make sure that the subscription from the base station is open. The user can either maintain a click on the Radio button on the DP750 BS for 7 seconds (Radio icon will start blinking) or click on Subscribe to open the subscription from DP750 WEB UI → Status → DECT Status.
Actually, DP720 doesn’t support roaming or handover, users need to switch from one base to another manually using the DP720 keypad Menu → Settings → Registration → Select Base.
Yes, DP750 can be powered via PoE IEEE802.3af Class 1.
Calling Features & Line Management
The user can call from another configured line from the DP720 handset without changing the outgoing default line. To do that, please enter the number to call directly on the keypad, then press the left soft key (Call). The available lines will be displayed, and the user can select which line to call.
Yes, the DP720 handset can use all SIP accounts registered on the DP750 base station (up to 10 SIP accounts) as lines to make/receive calls:
- Assign the SIP accounts as lines for a DP720 handset: Please access the DP750 web interface and go to DECT → Line Settings.
- Route all the incoming calls to the same handset only: Please access the DP750 web interface and go to DECT → SIP Account Settings and set the HS Mode for the accounts to the handset in question.
- Change the default outgoing line from a DP720 handset for outgoing calls: Using the keypad, please navigate through the Menu to Call Settings → Outgoing Default Line.
All the registered handsets to the DP750 base station may use the same SIP Account and share it across all the handsets, user needs to assign that sip account as line for the registered handsets from DP750 Web UI → DECT → Line Settings, and then use hunt group feature to allow this scenario, the DP750 offers different hunt group options to manage the incoming calls depending on his needs from DP750 WEB UI → DECT → SIP Account Settings and set the HS Mode for the SIP account:
- Circular: The base station will note which handset answered the last call, and forward the call to the next available handset in round-robin fashion.
- Linear: The base station will distribute the call in predesignated order from the lowest-numbered available handset. If no answer within the ring timeout, the call will be sent to the next available handset in sequence. This mode is also called “serial hunting”.
- Parallel: In this mode, all handsets ring concurrently. If one handset answers, the remaining available handsets can make new outgoing calls.
Internal calls between registered DP720s to the same DP750 base station are not supported. You will need to register SIP accounts on DP720 handsets to make calls between them.
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 the DP7xx handset and other VoIP Device have public IP addresses, or
- Both the DP7xx handset and other VoIP Device are on the same LAN using private IP addresses, or
- Both the DP7xx handset and other VoIP Device can be connected through a router using public or private IP addresses (with necessary port forwarding or DMZ).
Users can perform IP calls using the star code, following the steps below:
- Pick up the handset and press the dial key
- Dial *47 followed by the target IP Address.
You can enter directly *47 + target IP address, and then press the dial key to initiate the call.
Examples of direct IP calls
- 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 waiting 4 seconds. In this case, the default destination port 5060 is used if no port is specified.
- 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.
- Make sure that the “Use Random SIP Port” setting is set to No (DP75x GUI → Profiles → Profile X → SIP Settings → Basic Settings).
- Make sure that “Disable Direct IP Call” is set to No (DP75x GUI → Settings → System Features).
There are two ways to enable DND from the DP720 handset. The user may either enable the DND feature by dialing the star code *78. To disable the DND user should dial the star code *79. Or navigate through the keypad menu and go to Calls Settings → Do Not Disturb, and choose the line on which DND should be enabled/Disabled.
The user can lock/unlock the keypad of the handset by pressing the lock key button (#) for 2 seconds.
Handset & Phonebook Management
The name of a DP720 handset can be changed from its keypad menu by navigating to Settings → Handset Name. Or if the handset is registered with a base station, the user can change its name from DP750 WEB UI → DECT → General Settings → Handset Settings → Handset Name.
The user can upload different XML phonebooks to each registered DP720 handset without them being shared among them. Please log in to DP750 Web UI and go to Phonebook → Private Phonebook Settings. In this page user can import/export XML phonebooks privately to DP720 handsets.
An LDAP or XML Phonebook can be shared across all the registered handsets with a DP750 base station, and the shared phonebook can be accessible from the DP720 Keypad Menu → Contacts → Shared. Upload a phonebook into the base station to be shared by accessing the DP750 Web UI, and navigate to Phonebook. The user has the possibility to either upload automatically or manually an XML Phonebook (Global Phonebook XML Settings) or configure the base station with an LDAP Server (Global Phonebook LDAP Settings).
Configuration, Provisioning, & Firmware
The handset is not able to display the SIP Registration status; you need to check the status of the registration directly from your DP750 web interface under Status → Account Status → SIP Registration.
User 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: XML Configuration Guide
The DP750 can be upgraded via TFTP/HTTP/HTTPS by configuring the URL/IP Address for the TFTP/HTTP/HTTPS server and selecting a download method. Configure a valid URL for TFTP or HTTP/HTTPS; the server name can be an FQDN or IP address. Please follow the steps below to upgrade the firmware version of your DP750 base station:
- Access DP750 Web GUI.
- Press Login to access your settings.
- Go to Maintenance → Firmware Upgrade page, enter the IP address or the FQDN for the upgrade server in the “Firmware Server Path” field, and choose to upgrade via TFTP or HTTP/HTTPS.
- Make sure to configure Firmware Upgrade and Provisioning to Always Check for New Firmware.
- Update the change by clicking the “Save and Apply” button. Then, “Reboot” or power cycle the base station to update the new firmware. Examples of valid URLs: firmware.grandstream.com/BETA or fw.ipvideotalk.com/gs
User can upgrade manually the firmware on the DP720 to the latest firmware available on the DP750 base station on which the handset is registered, from DP720 Keypad Menu → Settings → Firmware Upgrade, or from DP750 WEB UI → Status → DECT Base Status → Upgrade. User can also configure an automatic upgrade for all the registered handsets to the base station from the DP750 WEB UI → Maintenance → Firmware Upgrade and set “Automatic Upgrade” to Yes for Handset Firmware.
User can either check the firmware version loaded to a handset directly from the DP720 Keypad Menu → Status, or if it’s registered with a DP750 base station, user can also check the firmware of the handset from DP750 Web GUI → Status → DECT Base Status → HS Firmware.
Troubleshooting & Maintenance
DP720 handset can be reset to initial configuration from Keypad Menu → Settings → System Settings → Factory Reset, and click on Yes (left soft key) to confirm, to cancel the Reset, press No soft key instead.
Please follow the instructions below to reset the DP750 base station:
- Access your DP750 base station web UI by entering its IP address in a browser.
- Enter your admin password (default: admin)
- Press Login to access your settings.
- Press the Factory Reset button on the top right corner. User can also perform a hard factory reset of the base by inserting a pin-sized needle into the reset hole on the back of the DP750 base station, and hold it for about 7 seconds, then release it (Network, SIP status, Phone, and Radio icon LEDs will start blinking to indicate that the factory reset process will be triggered).
The DP750 automatically syncs up the time with the configured NTP Server and adjusts the time depending on the selected time zone. When a DP720 handset is registered to the base station, the time will be synced up automatically between DP720 and DP750. If the time is not displayed correctly on the Handset, make sure that the DP750 base station is able to reach the NTP Server to sync up the date/time. You may try to reboot the base station.
Network & Security
This is a result of the device being port-scanned by external users. To avoid this issue, make sure to set “Only Accept SIP Requests from Known Servers” to Yes from the DP750 Web UI → Profiles → ProfileX(X=1-4) → SIP Settings → Security Settings.
Yes. Grandstream allows HTTPS provisioning with Grandstream’s very own certificate. If the server is configured to require a certificate for authentication, our devices can send an internal certificate that is flashed on all Grandstream devices. If you would like to use this feature, please get in contact with our Grandstream Support for the GS Certificate. Note: This is not the same as the “HTTP/HTTPS” user/password, which, in this case this option is for authentication only once the connection has been established.