This Frequently Asked Questions (FAQ) document provides concise answers and guidance for using the Grandstream audio IP phones, the GXP16XX Series. This FAQ is intended to assist administrators and users in resolving common issues and understanding key features.
Product Overview & Specifications
Supported only on the GXP1610P, GXP1615, GXP1625, GXP1628, and GXP1630.
Audio codecs supported: G7.29A/B, G.711µ/a-law, G.726, G.722(wide-band), G. 723, iLBC, OPUS, in-band and out-of-band DTMF (in audio, RFC2833, SIP INFO), VAD, AEC, CNG, PLC, AGC
Yes, GXP16XX IP phones have a built-in HD speaker that can be used during calls.
- GXP1610/1615: 3-way conference
- GXP1620/1625: 3-way conference
- GXP1628: 3-way conference
- GXP1630: 4-way conference
Yes, the user can connect a headset using an Electronic Hook Switch (EHS) using an RJ9 connector. E.g., Plantronics, Jabra, and Sennheiser headsets.
Setup & Registration
- GXP1610/1615: 2 SIP accounts, 2 lines.
- GXP1620/1625: 2 SIP accounts, 2 lines.
- GXP1628: 2 SIP accounts, 2 lines.
- GXP1630: 3 SIP accounts, 3 lines.
Yes, if activated, the user can make a direct IP call to another IP phone.
Yes, if the registration of the extension fails on the primary server. The IP phone will attempt to register to a secondary server using the same SIP extension number and authentication password.
Yes, GXP16XX IP phones can be connected and authenticated over PPPoE.
Provisioning can be done in various ways. It can be provisioned using our solutions, like our cloud management and provisioning solution, the GDMS Unified Communication. It can also be done using our provisioning solution embedded in the UCM6300/A Series, SoftwareUCM, and GCC Series, called Zero Config.
If the user intends or already has a provisioning service, they can provision the IP phones using XML file templates over TFTP, HTTP, HTTPS, FTP, FTPS.
Yes, the user can define the function of a soft key based on the context. For example, the user can set a soft key to perform a certain action depending on whether the phone is in the idle screen or in the call screen.
Yes, configuring the VLAN on the IP phone provides enhanced security by isolating the media traffic of the phone from the other traffic. This also makes management of the traffic, like quality of service, very easy.
GXP16XX IP phones support QoS on both Layer 2 and Layer 3. On Layer 2, it supports 802.1p. On Layer 3, it supports ToS, DiffServ, and MPLS.
Calling Features & Line Management
Do Not Disturb can be enabled in multiple ways.
Using the LCD screen:
- Press the Menu button and navigate to “Settings 🡪 Call Settings 🡪 Do Not Disturb”.
- Use the RIGHT/LEFT keys to disable/enable DND.
- Press the “Save” softkey to save the change
Using the mute button:
Pressing the mute button while the phone is idle activates DND.
The GXP16XX series phone supports the Alert-Info mapping to the 3 custom ringtone files. For example, if you configure the Matching Incoming Caller ID to “priority”, the ring tone will be used if we receive INVITE with Alert-Info header in the following format: Alert-Info:;info=priority
The GXP16XX IP phones can store locally up to 1000 contacts.
Yes, integration with LDAP allows the administrator to manage the contacts on the LDAP server, and the user can search the LDAP contact directory from the GXP16XX IP phones.
Configuration, Provisioning, & Firmware
The device configuration interface can be accessed by following the steps below:
- Make sure that GXP16XX boots up and is connected to the network.
- To display the IP address, press and hold the UP button on the keypad.
- Enter the IP address of the device in the browser.
- The default administrator username is “admin”, and the password can be found on the label at the bottom of the device.
The current firmware version of the device can be found on web UI and LCD menu:
– Web UI: Status > System Info > System Version
– LCD: Settings > Status > System > System Version.
GXP16XX supports firmware upgrade via the following methods:
- Method 1: Upgrade via HTTP, HTTPS, FTP, FTPS, or TFTP server.
- Method 2: Upgrade via Zero Config if the newer firmware is uploaded to the IPPBX.
To save a backup file of the configuration of the GXP16XX IP phone, please follow the steps mentioned below.
- Access the webUI and use the administrator’s credentials to log in.
- Navigate to Maintenance > Upgrade and Provisioning
- Click on “Download Device Configuration” to download the configuration file in .txt format. The user also downloads the config file in xml format.
Troubleshooting & Maintenance
A factory reset could be executed from the web UI or LCD menu.
– Web UI: Maintenance > Upgrade > Advanced settings > Factory Reset.
– LCD: Settings > Advanced > Factory Reset.
You should make sure that the phone is connected to the network and that it is able to obtain an IP address. Secondly, check if the account is set to active by setting the “Account Active” configuration in the Account page of the web interface to “Yes”. Additionally, check if the login information and the SIP server are correct. If the SIP server is wrong, the phone cannot contact the SIP server for registration. If the login information is wrong, the SIP server will reject the registration request of the phone.
If the number of concurrent registrations is restricted to 1 registration and there is already one registration, with no possibility to seize the registration. This means that another phone/SIP client is already registered to that extension.
If all of the above are correct, there may be a problem with NAT traversal. If the GXP16XX is on a LAN and needs to register with a SIP server on a public IP, please enable NAT traversal by selecting the NAT traversal method according to your network environment. If you are unsure, it is recommended to select “Auto” to enable the automatic NAT traversal configuration feature.
When this situation occurs, please check if the handset is securely connected. If it is not, please reconnect it. It could also be caused by the following:
- The other party may have pressed the “Mute” key, which will place the call on mute. Please tell the other party to check if Mute is on and unmute the call.
- If your phone is connected to the Internet through a router, this can be caused by the NAT traversal issue. If the GXP16XX is on a LAN and needs to register with a SIP server on a public IP, please enable NAT traversal by selecting the NAT traversal method according to your network environment. If you are unsure, it is recommended to select “Auto” to enable the automatic NAT traversal configuration feature.
If such behavior occurs, one of the possible reasons is that there is an encryption feature configuration mismatch. Either encryption is forced on one end but disabled on the other end, or the encryption protocols selected on either end are not selected on the other end.
Network & Security
Yes, the GXP16XX phones can be registered using SIP over TLS, and all the subsequent SIP messages will also be transported over TLS. E.g., REGISTER, SUBSCRIBE, NOTIFY, etc…
Yes, the media traffic can be encrypted on the GXP16XX IP phones. The encryption parameters on the phone must be in accordance with the encryption parameters on the IPPBX to ensure successful encryption and decryption.
Yes, the GXP16XX supports 802.1X protocol authentication.