Grandstream Networks GXP21 Series User manual

Grandstream Networks, Inc. GXP21xx User Manual Page 1 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Grandstream Networks, Inc.
GXP21xx SIP Enterprise Phones

Grandstream Networks, Inc. GXP21xx User Manual Page 2 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
TABLE OF CONTENTS
GXP21XX USER MANUAL
WELCOME .................................................................................................................................................................4
INSTALLATION.........................................................................................................................................................5
EQUIPMENT PACKAGING.............................................................................................................................................5
CONNECTING YOUR PHONE ........................................................................................................................................5
GXP2120/2110 EXTENSION UNIT...............................................................................................................................5
SAFETY COMPLIANCES................................................................................................................................................7
WARRANTY.................................................................................................................................................................7
PRODUCT OVERVIEW............................................................................................................................................8
USING THE GXP21XX SIP ENTERPRISE PHONE ...........................................................................................12
GETTING FAMILIAR WITH THE LCD..........................................................................................................................12
MAKING PHONE CALLS.............................................................................................................................................15
ANSWERING PHONE CALLS.......................................................................................................................................18
PHONE FUNCTIONS DURING A PHONE CALL .............................................................................................................18
CALL FEATURES........................................................................................................................................................21
CUSTOMIZED LCD SCREEN &XML.........................................................................................................................21
CONFIGURATION GUIDE......................................................................................................................................22
CONFIGURATION VIA KEYPAD..................................................................................................................................22
CONFIGURATION VIA WEB BROWSER ......................................................................................................................25
SAVING THE CONFIGURATION CHANGES...................................................................................................................39
REBOOTING THE PHONE REMOTELY..........................................................................................................................39
SOFTWARE UPGRADE & CUSTOMIZATION..................................................................................................40
FIRMWARE UPGRADE THROUGH TFTP/HTTP..........................................................................................................40
CONFIGURATION FILE DOWNLOAD ...........................................................................................................................41
RESTORE FACTORY DEFAULT SETTING.......................................................................................................42
TABLE OF FIGURES
GXP21XX USER MANUAL
Figure 1: Connecting the GXP2120/2110 and the GXP–Extension ...............................................6
Figure 2: Keypad GUI Flow............................................................................................................24
TABLE OF TABLES
GXP2120 USER MANUAL
Table 1: Equipment Packaging.......................................................................................................5
Table 2: GXP Connectors...............................................................................................................5
Table 3: GXP21xx Product Models .................................................................................................8
Table 4: GXP21xx Comparison Guide ............................................................................................8
Table 5: GXP21xx Key Features in a Glance.................................................................................8
Table 6: GXP21xx Hardware Specifications...................................................................................9
Table 7: GXP21xx Technical Specifications...................................................................................9
Table 8: LCD Buttons....................................................................................................................12

Grandstream Networks, Inc. GXP21xx User Manual Page 3 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Table 9: LCD Icons .......................................................................................................................13
Table 10: GXP21xx Keypad Buttons ............................................................................................14
Table 11: GXP Call Features........................................................................................................21
Table 12: Key Pad Configuration Menu........................................................................................22
Table 13: Device Configuration - Status........................................................................................26
Table 14: Device Configuration –Settings/Basic Settings............................................................26
Table 15: Device Configuration –Settings /Advanced Settings ..................................................28
Table 16: SIP Account Settings ....................................................................................................33
GUI INTERFACE EXAMPLES
GXP21XX USER MANUAL
(http://www.grandstream.com/support/gxp_series/general/documents/gxp21xx_gui.zip)
1. SCREENSHOT OF CONFIGURATION LOGIN PAGE
2. SCREENSHOT OF STATUS PAGE
3. SCREENSHOT OF BASIC SETTINGS CONFIGURATION PAGE
4. SCREENSHOT OF ADVANCED USER CONFIGURATION PAGE
5. SCREENSHOT OF SIP ACCOUNT CONFIGURATION
6. SCREENSHOT OF SAVED CONFIGURATION CHANGES
7. SCREENSHOT OF REBOOT PAGE

Grandstream Networks, Inc. GXP21xx User Manual Page 4 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Welcome
Your Grandstream GXP21xx Enterprise IP phone is feature-enriched, sophisticated, yet simple to use.
The GXP21xx delivers superior HD audio quality, rich and leading edge telephony features, personalized
information and customizable application service, automated provisioning for easy deployment, advanced
security protection for privacy, and broad interoperability with most 3rd party SIP devices and leading
SIP/NGN/IMS platforms.
The GXP21xx supports a broad range of codecs, security protection, PoE, dual 10/100mbps Ethernet
ports, along with customizable XML provisioning and application features. Users can expect superior
audio quality using the new high definition handset, hands-free speakerphone, or headset. Also, it can
support up to 5-way conferencing, multi-languages, dual-color LEDs, presence and Busy Lamp Field
(BLF). It presents a large easy-to-read backlit graphical display along with multiple XML keys to further
enhance the user experience. The GXP2120/2110 is also expandable with one to two expansion modules.
The GXP21xx is a perfect choice for enterprise users looking for a high quality, feature rich multi-line IP
phone with the best values.
Caution: Changes or modifications to this product not expressly approved by Grandstream, or operation
of this product in any way other than as detailed by this User Manual, could void your manufacturer
warranty.
Warning: Please do not use a different power adaptor with the GXP as it may cause damage to the
products and void the manufacturer warranty.
This document is contains links to Grandstream GUI Interfaces. Please download these examples
from http://www.grandstream.com/support/gxp_series/general/documents/gxp21xx_gui.zip for your
reference.
This document is subject to change without notice. The latest electronic version of this user manual
is available for download @:
http://www.grandstream.com/support/gxp_series/general/documents/gxp21xx_usermanual_english.p
df
Reproduction or transmittal of the entire or any part, in any form or by any means, electronic or print,
for any purpose without the express written permission of Grandstream Networks, Inc. is not
permitted.

Grandstream Networks, Inc. GXP21xx User Manual Page 5 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Installation
EQUIPMENT PACKAGING
Table 1: Equipment Packaging
GXP-2120
GXP-2110
GXP-2100
Main Case
Yes
Yes
Yes
Handset
Yes
Yes
Yes
Phone Cord
Yes
Yes
Yes
Power Adaptor
Yes
Yes
Yes
Ethernet Cable
Yes
Yes
Yes
High Phone Stand
Yes
Yes
Yes
Low Phone Stand
Yes
Yes
No
Wall Mount Spacers (2)
Yes
Yes
Wall Mount stand
CONNECTING YOUR PHONE
The connectors of the GXP21xx are located on the bottom of the device.
Table 2: GXP Connectors
EXT
Connects the GXP Extension unit directly to the GXP using connection cable.
Draws power from PoE if provided by network. (Not applicable on GXP2100)
PC
10/100Mbps RJ-45 ports for PC (downlink) connection.
LAN
10/100Mbps RJ-45 port for LAN (uplink) connection. Supports PoE (802.3af).
Draws power from either spare line or signal line.
Power Jack
5V DC power port; UL Certified
Headset Jack
RJ9 and 2.5mm
Handset Jack
RJ11
GXP2120/2110 EXTENSION UNIT
GXP2120/2110 supports two (2) extension units, providing up to 112 additional programmable extensions.
Each GXP Extension unit has 56 multi–purpose keys, dual color LEDs (red/green) and support BLF (Busy
Lamp Field) and Presence.
GXP2120/2110 Extension package contains:
1) One GXP Extension unit
2) Two connection cables
3) One Universal Power Adaptor

Grandstream Networks, Inc. GXP21xx User Manual Page 6 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
FIGURE 1: CONNECTING THE GXP2120/2110 AND THE GXP–EXTENSION
GXP–2120 w/GXP–Extension
GXP Extension
Connecting the GXP–2120/2110
w/GXP–Extension
Reverse side of connection
w/connection plate
Reverse side of connection w/connection
plate
GXP2120/2110 has a special port on
the back.
Connect the first GXP-EXT to the GXP2120/2110 using the connection cable found in the GXP Extension
package. The first GXP-EXT draws power directly from the phone. Connect the second GXP Extension unit
using the connection plate and the connection cable. The GXP2120/2110 will automatically reboot and
power up the GXP Extensions. Grandstream recommends, though not required, to use a separate power
supply with the second GXP-EXT.
NOTE: Should your system lose power, please unplug your devices and power up the GXP2120/2110 first.
Powering up the system:
1. The GXP will boot up first;
2. The GXP LEDs will be solid red;
3. The status light in the top right corner of the GXP–Ext will blink red;
4. All of the LED indicators on the GXP–Ext will flash three times;
5. The status light at the top right corner of the GXP–Ext will turn to solid green.
NOTE:
1. Extension for GXP2120/2110 is the same for GXP2020/2010 models. However, GXP2120/2110
uses a different-shaped connector for the special port (as shown above). Extension cables will be
included with the extension board.
2. Extension for GXP2120/2110 does not support hot-swap. Once connected, user should reboot the
phone to ensure the set up will work correctly.
3. GXP2120/2110 can drive 2 extension modules. Independent power adapters are not needed for
extension modules.

Grandstream Networks, Inc. GXP21xx User Manual Page 7 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
SAFETY COMPLIANCES
The GXP phone complies with FCC/CE and various safety standards. The GXP power adaptor is compliant
with the UL standard. Only use the universal power adaptor provided with the GXP package. The
manufacturer‟s warranty does not cover damages to the phone caused by unsupported power adaptors.
WARRANTY
If you purchased your GXP from a reseller, please contact the company where you purchased your phone
for replacement, repair or refund. If you purchased the product directly from Grandstream, contact your
Grandstream Sales and Service Representative for a RMA (Return Materials Authorization) number before
you return the product. Grandstream reserves the right to remedy warranty policy without prior notification.

Grandstream Networks, Inc. GXP21xx User Manual Page 8 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Product Overview
Table 3: GXP21xx Product Models
Model
Picture
Overview
GXP2120
GXP2120 is an executive SIP phone. It features:
Six lines
Seven programmable hard keys
Four XML programmable soft keys
GXP2110
GXP2110 is an executive SIP phone. It features:
Four lines
Eighteen programmable hard keys
Three XML programmable soft keys
GXP2100
GXP2100 is an executive SIP phone. It features:
Four lines
Seven programmable hard keys
Three XML programmable soft keys
Table 4: GXP21xx Comparison Guide
Features
GXP2120
GXP2110
GXP2100
LCD Display
320x160 pixel
240x120 pixel
180x90 pixel
Number of Lines
6
4
4
Programmable Hard Keys
7
18
7
Programmable Soft Keys
4
3
3
Extension Module
Yes, up to 2 Expansion
Modules, 56 nodes each
Yes, up to 2 Expansion
Modules, 56 nodes
each
N/A
Table 5: GXP21xx Key Features in a Glance
Features
Benefits
Open Standards
Compatible
SIP 2.0, TCP/IP/UDP, RTP/RTCP, HTTP/HTTPS, ARP/RARP, ICMP, DNS (A record and
SRV), DHCP (both client and server), PPPoE, TFTP, NTP, Telnet, and SIP over TLS,

Grandstream Networks, Inc. GXP21xx User Manual Page 9 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
802.1x, TR-069
Superb Audio
Quality
Advanced Digital Signal Processing (DSP), Silence suppression, VAD, CNG, AGC.
Network
Interfaces
Dual 10/100mbps Ethernet ports
Feature Rich
Traditional voice features including caller ID, call waiting, hold, transfer, forward, block,
autodial, off-hook dial.
Advanced
Features
Multi-line support with dual-color LED, multi-party conferencing, line extension interface,
large back-lit graphic LCD, 5 or 3 navigation keys, dedicated buttons for hold, send,
speakerphone, headset, transfer, conference (for up to 5 parties depending on model),
mute, message, Do-Not-Disturb, phone book, intercom/paging.
Advanced
Functionality
Custom down-loadable ring-tones, SRTP, SIP over TLS, multi-language support and XML
enabled, adjustable positioning angles, wall mountable, AES encryption.
Table 6: GXP21xx Hardware Specifications
GXP2120
GXP2110
GXP2100
LAN Interface
(Ethernet ports)
Two (2) 10/100 Mbps Full/Half Duplex Ethernet Switch with LAN and PC port with
auto detection
Graphic LCD
Display
320x160 pixel
240x120 pixel
180x90 pixel
Expansion Module
Support
Yes
No
Headset Jack
2.5mm and RJ9
Call Appearance
LED
13 Dual color (green/red)
22 Dual color
(green/red)
11 Dual color
(green/red)
Power over
Ethernet
Built-in auto-sensing: Cisco and IEEE 802.3af standard
Universal
Switching
Input: 100-240VAC 50-60 Hz
Input: 100-240VAC 50-
60 Hz
Input: 100-240VAC 50-
60 Hz
Power Adaptor
Output: +5VDC, 800mA, UL
certified
Output: +5VDC, 800mA,
UL certified
Output: +5VDC, 800mA,
UL certified
Dimension
251mm(W) x 202mm(L) x
77mm(H)
252mm (W) x 210mm
(L) x 78mm (H)
222mm (W) x 210mm
(L) x 93mm (H)
Weight
1.66KG (3.64lbs)
1.78KG (3.92lbs)
1.63KG (3.59lbs)
Temperature
32 –104° F/ 0 –40°C
Humidity
10% –90% (non-condensing)
Compliance
FCC / CE / C-Tick
Table 7: GXP21xx Technical Specifications

Grandstream Networks, Inc. GXP21xx User Manual Page 10 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Lines
Multiple direct lines with independent SIP accounts, programmable speed dial keys,
XML programmable soft-keys.
Protocol
Support
Support SIP 2.0, TCP/UDP/IP, PPPoE, RTP/RTCP, SRTP by SDES, HTTP,
ARP/RARP, ICMP, DNS, DHCP, NTP, TFTP, SIMPLE/PRESENCE protocols, TR-
069, 802.1x.
Support multiple SIP accounts and up to 11 media channels concurrently
Support SIP PUBLISH method (RFC 3903), SIP Presence package (RFC 3856,
3863) for use of MFKs, SIP Dialog package (RFC 4235)
Support for SIP MESSAGE method (RFC 3428)
Display
Back-lit graphic LCD display, up to 8 level grayscale
Feature Keys
GXP2120
GXP2110
GXP2100
HOLD
Yes
Yes
Yes
SPEAKERPHONE
Yes
Yes
Yes
SEND
Yes
Yes
Yes
TRANSFER
Yes
Yes
Yes
CONF
Yes
Yes
Yes
MUTE
Yes
Yes
Yes
DND
Yes
Yes
No
HEADSET
Yes
Yes
Yes
INTERCOM
Yes
Yes
Yes
PHONEBOOK
Yes
Yes
Yes
MSG
Yes
Yes
Yes
MENU
Yes
Yes
Yes
NAVIGATION (4)
Yes
Yes
Yes
Device
Management
NAT-friendly remote software upgrade (via TFTP/HTTP) for deployed devices
including behind firewall/NAT
Auto/manual provisioning system, GUI Interface
Support Layer 2 (802.1Q, VLAN, 802.1p) and Layer 3 QoS (ToS, DiffServ, MPLS)
Expansion interface, Address Book
Audio Features
Full-duplex hands-free speakerphone, headset enabled
Advanced Digital Signal Processing (DSP)
Dynamic negotiation of codec and voice payload length
Support for G.723,1 (5.3/6.3K), G.729A/B, G.711 a/µ-law, G.726-32, G.722 (wide-
band), and iLBC codecs
In-band and out-of-band DTMF (in audio, RFC2833, SIP INFO)
Silence Suppression, VAD (voice activity detection), CNG (comfort noise
generation), ANG (automatic gain control)
Acoustic Echo Cancellation (AEC) with Acoustic Gain Control (AGC) for
speakerphone mode, Support side tone
Adaptive jitter buffer control (patent-pending) and packet delay & loss concealment.
HD audio handset with HD wideband audio codecs for excellent double-talk
performance.
Telephony
Features
Intuitive graphic user interface (GUI), downloadable phone book (XML, LDAP),
support for anonymous call using privacy header, MLS (multi language support)
Voice mail indicator, downloadable custom ring-tones, call hold, call transfer
(attended/blind), call forward, call waiting, caller ID, mute, redial, call log, caller ID

Grandstream Networks, Inc. GXP21xx User Manual Page 11 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
display or block, Do-Not-Disturb (DND) and volume control
Multi-party conferencing (up to 5), dial plan prefix, dial-plan support, off-hook auto
dial, auto answer, early dial and speed dial.
Network and
Provisioning
Via keypad/LCD, Web browser, or secure (AES encrypted) central configuration file,
manual or dynamic host configuration protocol (DHCP) network setup
Support NAT traversal using IETF STUN and Symmetric RTP
Support for IEEE 802.1p/Q tagging (VLAN), Layer 3 TOS
Firmware
Upgrades
Support firmware upgrade via TFTP or HTTP,
Support for Authenticating configuration file before accepting changes
User specific URL for configuration file and firmware files
Advanced
Server Features
Message waiting indication, support DNS SRV Look up and SIP Server Fail Over,
Support customizable idle screen via downloading XML by HTTP/TFTP
Security
User and administrator level passwords, MD5 and MD5-sess based
authentication, AES based secure configuration file, SRTP, TLS, 802.1x
media access control

Grandstream Networks, Inc. GXP21xx User Manual Page 12 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Using the GXP21xx SIP Enterprise Phone
GETTING FAMILIAR WITH THE LCD
GXP21xx has a dynamic and customizable screen. The screen displays differently depending on whether the
phone is idle or in use (active screen).
Table 8: LCD Buttons
Key Button
Key Button Definitions
LINE
SELECTORS
Selects the phone line printed on its right-hand side.
SIP PHONE
LINES
Displays the available phone lines. Choose a phone line by pressing the corresponding line
selector on the left-hand side.
DATE AND
TIME
Displays the current date and time. Can be synchronized with Internet time servers.
LOGO
Displays company logo. This logo can be customized. For more information on customizing the
logo, please check page 24.
NETWORK
STATUS
Shows the status of the phone and network. It will indicate whether the network is down, starting
or is running (show IP-number). Other messages such as “DO NOT DISTURB” or “## MISSED
CALLS” are shown here too.
STATUS
BAR
Shows the status of the phone, using icons as shown in the next table.
LINE
STATUS
INDICATOR
Displays the name of the account that is in use. Select another account by pressing the LINE
SELECTOR BUTTONS
SOFT-
BUTTONS
The soft-buttons are context sensitive and will change depending on the status of the phone.
Typical functions assigned to soft-buttons are:
NEW CALL Press this button to make a new hand-free call.
FORWARD ALL Unconditionally forwards the main phone line to another phone
MISSED CALLS This option shows up if there were unanswered calls to this phone. The
Missed Calls option shows a list of the missed calls
SWITCHSCR Press this button to toggle between XML applications such as weather,
stocks, and currency.
CALL RETURN Calls the phone that called/tried to call your phone last.
REDIAL Redials the last number
END CALL Hangs up phone

Grandstream Networks, Inc. GXP21xx User Manual Page 13 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
SPECIAL
SOFT
BUTTONS
(Only When
Integrated
with
GXE5024/502
8)
Call Parking: FOR GXP2120/GXP2110 ONLY. Refer to the GXE5024/5028 Online User Manual
for more information.
CallPark When a GXP2120 dials out, the Call Park soft button will display
on screen. To park the call, press the „Call Park‟ button.
PickUp When another GXP2120 goes off-hook the Call Pickup soft button
will display on screen. To pickup the parked call, press the „Call
Pickup‟ button.
Call Queue: FOR GXP2120/211 ONLY. Refer to the GXE5024/5028 Online User Manual for
more information.
SignIn Press this button to sign in to the call queue. Agent will be prompted in
the LCD display to select the call queue to join. Press „menu‟ button on
keypad to select „ok‟. Once the agent completely signs in, the agent will
be brought back to the main screen.
SignOut Press this button to sign out of the call queue. Press‟ menu‟ button on
keypad to select „ok‟. This will be displayed once the agent is signed in to
the call queue.
PUBLIC MODE (Also mentioned on p.31 of this manual): This useful mode complements the
Call Queue feature by allowing various user agents to log in/log off, sharing the same phone.
When enabled, all other accounts on the phone will not be active. For more information, refer to
http://www.grandstream.com/support/gxe_series/gxe502x/documents/gxe502X_call_queue_wit
h_gxp.pdf
LogIn Press this button to log in the user agent into the call queue.
Tab Press this button to jump to toggle between UserName and Password
entry fields.
Backspace Press this button to erase the previously typed digit, letter, or character.
LogOut Press this button to log out the user agent out of the call queue.
Table 9: LCD Icons
Icon
LCD Icon Definitions
Connectivity Status / SIP Proxy/Server Icon:
Solid –connected to SIP Server/IP address received
Blinking –physical connection failed
Blank –SIP Proxy/Server not registered
Phone Status Icon:
OFF when the handset is on-hook
ON when the handset is off-hook
Speaker Phone Status Icon:
FLASH when phone rings or a call is pending
OFF when the speakerphone is off
ON when the speakerphone is on
DND Icon:
ON when the “Do Not Disturb” is activated

Grandstream Networks, Inc. GXP21xx User Manual Page 14 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Calls Forwarded Icon:
INDICATES calls are forwarded
Follow „call forwarding‟ procedures
Handset, Speakerphone and Ring Volume Icon:
Each icon appears next to the volume icon
To adjust volume, use the up/down button
Real–time Clock:
Synchronized to Internet time server
Time zone configurable via web browser
AM/PM indicator
Table 10: GXP21xx Keypad Buttons
Key Button
Key Button Definitions
LINE BUTTONS
Line keys with LED, can be configured to different SIP profiles
TRANSFER
TRANSFER key: Transfer an ACTIVE call to another number
CONF
Press CONF button to connect Calling/Called party into conference
MUTE
Mute an active call; or Delete a key entry
Also used to „REJECT‟ incoming call.
HOLD
Place ACTIVE call on hold
MSG
Enter to retrieve voice mails or other messages
Enable/Disable hands-free speaker mode
SEND
Press SEND to dial a new number or redial the last number dialed. Press
send button to send a call immediately before “no key entry timeout” value
expires
Enter to retrieve voice mails or other messages
MENU
Enter Keypad Configuration “MENU” mode when phone is in IDLE mode.
Use as ENTER key when in Keypad Configuration.
0 - 9, *, #
Standard phone keypad; press # key to send call; press * key to for IVR
functions
DND
DO NOT DISTURB key; Press DND to turn “Do not disturb” function on or off.
(Excluded on GXP2100)
HEADSET
Press HEADSET key to answer/hang up phone calls while using headset. It
also allows user to toggle between headset and speaker.
INTERCOM
Turn intercom function on/off
Brings phonebook on screen
PM
AM

Grandstream Networks, Inc. GXP21xx User Manual Page 15 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
MAKING PHONE CALLS
Handset, Speakerphone and Headset Mode
The GXP21xx allows you to make phone calls via handset, speakerphone, or headset mode. During the
active calls the user can switch between the handset and the speaker by pressing the speaker key. For
headsets to operate, the user must plug the headset to an RJ9 or 2.5mm port on the phone, which allows the
user to pick-up, speak, or hang-up calls.
Multiple SIP Accounts and Lines
GXP2120 can support up to six independent SIP accounts. Each account is capable of independent SIP
server, user and NAT settings. Each of the line buttons is “virtually” mapped to an individual SIP account.
The name of each account is conveniently printed next to its corresponding button. In off-hook state, select
an idle line and the name of the account (as configured in the web interface) is displayed on the LCD and a
dial tone is heard.
For example: Configure ACCOUNT 1 and ACCOUNT 2 with Account Name as “VoIP 1”, “VoIP 2”,
respectively and ensure that they are active and registered. When LINE1 is pressed, you will hear a dial
tone and see “VoIP 1” on the LCD display; when LINE2 is pressed, you will hear a dial tone and see “VoIP 2”
on the LCD display.
To make a call, select the line you wish to use. The corresponding LINE LED will light up in green. User can
switch lines before dialing any number by pressing the same LINE button one or more times. If you continue
to press a LINE button, the selected account will circulate among the registered accounts.
For example: when LINE1 is pressed, the LCD displays “VoIP 1”; If LINE1 is pressed twice, the LCD
displays “VoIP 2” and the subsequent call will be made through SIP account 2.
Incoming calls to a specific account will attempt to use its corresponding LINE if it is not in use. When the
“virtually” mapped line is in use, the GXP will flash the next available LINE (from left to right or from top to
bottom for Multi Purpose Keys) in red. A line is ACTIVE when it is in use and the corresponding LED is red.
Completing Calls
There are six ways to complete a call:
1. DIAL:To make a phone call.
Take Handset/SPEAKER/Headset off-hook
or press an available LINE key (activates speakerphone)
or press the NEW CALL soft-key.
The line will have a dial tone and the primary line (LINE1) LED is red.
If you wish, select another LINE key (alternative SIP account).
Enter the phone number
Press the SEND key
or press the “DIAL” soft-key.
2. REDIAL:To redial the last dialed phone number.
When redialing the phone will use the same SIP account as was used for the last call. Thus, when
the third SIP account was made for the last call/call attempt, the phone will use the third account to
redial.
Take Handset/SPEAKER/Headset off-hook or
press an available LINE key (activates speakerphone), the corresponding LED will be red.
Press the SEND button
or press the REDIAL soft-key.

Grandstream Networks, Inc. GXP21xx User Manual Page 16 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
3. CALL RETURN:To call the last phone number that called your phone.
When returning a call, the phone will use the same SIP account as the call was made to. Thus, when
returning a call made to the third SIP account, the phone will use the third SIP account return the
call.
i. Hand-free option
1. Press the CALL RETURN soft-key
ii. Hand-set option
1. Take the Handset off-hook
2. Press the CALL RETURN soft-key
4. USING THE CALL HISTORY:To call a phone number in the phone‟s history
When using the call history, the phone will use the same SIP account as was used for the last
call/call attempt. Thus, when returning a call made to the third SIP account, the phone will use the
third SIP account return the call.
Press the MENU button to bring up the Main Menu.
Select Call History and then “Received Calls”, “Missed Calls” or “Dialed Calls” depending on
your needs
Select phone number using the arrow keys
Press OK to select
Press OK again to dial.
5. USING THE PHONEBOOK:Calling a phone in from the phone‟s phonebook.
Each entry in the phonebook can be attached to an individual SIP account. The phone will use that
SIP account to make the phone call.
Go to the phonebook by:
i. Pressing the phonebook button (bottom, left-hand side of phone), or
ii. Pressing the DOWN arrow key, or
iii. Pressing the menu button and
Selecting “Phone book” and
Press MENU
Select the phone number by using the arrow keys
Press OK so select
Press OK again to dial.
6. PAGING/INTERCOM:
The paging/intercom function can only be used if the SERVER/PBX supports this feature and both
the phones and PBX are correctly configured.
Take the Handset/SPEAKER/Headset off-hook,
Select the LINE key associated with account
Press OK key to display LCD: LINEx: PAGE.
Dial the phone number you want to Page/Intercom
Press SEND key.
NOTE: Dial-tone and dialed number display occurs after the handset is off-hook and the line key is selected.
The phone waits 4 seconds (by default; No key Entry Timeout) before sending and initiating the call. Press
the “SEND” or “#” button to override the 4 second delay.
Speed Dial
The Multi Purpose Key buttons, located on the right-hand-side of the phone, can be configured for speed
dial. Press the speed dial button to automatically call the assigned extension.

Grandstream Networks, Inc. GXP21xx User Manual Page 17 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
Note: The multi-functional buttons will function as LINE keys when all LINEs are busy. The LED will flash in
red to indicate an incoming call. Press the button to pick up the call. If any one of the Multi Purpose Keys is
associated with a call, the button‟s speed dial/BLF function will not work.
Making Calls using IP Addresses
Direct IP calling allows two phones to talk to each other in an ad-hoc fashion without a SIP proxy. VoIP calls
can be made between two phones if:
Both phones have public IP addresses, or
Both phones are on a same LAN/VPN using private or public IP addresses, or
Both phones can be connected through a router using public or private IP addresses (with necessary
port forwarding or DMZ)
To make a direct IP call, please follow these steps:
1. Press MENU button to bring up MAIN MENU.
2. Select “Direct IP Call” using the arrow-keys.
3. Press OK to select.
4. Input the 12-digit target IP address. (Please see example below).
5. Press OK key to initiate call.
To make a quick IP call, please see next section.
For example: If the target IP address is 192.168.1.60 and the port is 5062 (e.g. 192.168.1.60:5062), input
the following: 192*168*1*60#5062 - The “ *”key represent the dot“.”; The “#”key represent colon “:”.
Press OK to dial out.
Quick IP Call Mode
The GXP21xx also supports Quick IP call mode. This enables the phone to make direct IP-calls, using only
the last few digits (last octet) of the target phone‟s IP-number.
This is possible only if both phones are in under the same LAN/VPN. This simulates a PBX function using
the CMSA/CD without a SIP server. Controlled static IP usage is recommended.
Setting up the phone to make Quick IP calls
To enable Quick IP calls, the phone has to be setup first. This is done through the web-setup function. In the
“Advanced Settings” page, set the "Use Quick IP-call mode to YES. When #xxx is dialed, where x is 0-9 and
xxx <=255, a direct IP call to aaa.bbb.ccc.XXX is completed. “aaa.bbb.ccc” is from the local IP address
regardless of subnet mask. The numbers #xx or #x are also valid. The leading 0 is not required (but OK).
For example:
192.168.0.2 calling 192.168.0.3 -- dial #3 follow by SEND or #
192.168.0.2 calling 192.168.0.23 -- dial #23 follow by SEND or #
192.168.0.2 calling 192.168.0.123 -- dial #123 follow by SEND or #
192.168.0.2: dial #3 and #03 and #003 results in the same call -- call 192.168.0.3
NOTE: If you have a SIP Server configured, a Direct IP-IP still works. If you are using STUN, the Direct IP-
IP call will also use STUN. Configure the “Use Random Port” to “NO” when completing Direct IP calls.

Grandstream Networks, Inc. GXP21xx User Manual Page 18 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
ANSWERING PHONE CALLS
Receiving Calls
1. Incoming single call: Phone rings with selected ring-tone. The corresponding account LINE
flashes red. Answer call by taking Handset/SPEAKER/Headset off hook or pressing SPEAKER or
by pressing the corresponding account LINE button.
2. Incoming multiple calls: When another call comes in while having an active call, the phone will
produce a Call Waiting tone (stutter tone). Next available lines will flash red (as described in section
4.3.2). Answer the incoming call by pressing its corresponding LINE button. The current active call
will be put on hold.
3. Paging/Intercom Enabled: Phone beeps once and automatically establishes the call via
SPEAKER. (PBX (or Server) must also supports this feature)
Do Not Disturb
1. Press the “DND” button if you do not want to take a call. This will send the caller directly to
voicemail.
2. Press the “DND” button to set phone to „do not disturb‟ (icon will be on the screen). The phone will
not ring and send caller directly to voicemail. (see note above)
PHONE FUNCTIONS DURING A PHONE CALL
Call Waiting/ Call Hold
1. Hold:Place a call on „hold‟ by pressing the “HOLD” button.
2. Resume: Resume call by pressing the corresponding blinking LINE.
3. Multiple Calls:Automatically place ACTIVE call on „HOLD‟ by selecting another available LINE to
place or receive another call. Call Waiting tone (stutter tone) audible when line is in use.
Mute/Delete
1. Press the MUTE button to enable/disable muting the microphone.
2. The “Line Status Indicator” will show “LINEx: SPEAKING” or “LINEx: MUTE” to indicate whether the
microphone is muted.
Call Transfer
GXP21xx supports both Blind and Attended (or supervised) transfer:
1. Blind Transfer: Press “TRANSFER”button, then dial the number and press the “SEND” button to
complete transfer of active call.
2. Attended (or Supervised) Transfer: Press “LINEx” button to make a call and automatically place
the ACTIVE LINE on HOLD. Once the call is established, press “TRANSFER” key then the LINE
button of the waiting line to transfer the call. Hang up the phone call after “Transfer Successful” is
displayed in the screen.
NOTE: To transfer calls across SIP domains, SIP service providers must support transfer across SIP
domains. Blind transfer will usually use the primary account SIP profile.

Grandstream Networks, Inc. GXP21xx User Manual Page 19 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
5-Way Conferencing
GXP can host conference calls and supports up to 5-way conference calling (Excludes GXP2100 which
supports up to 4-way).
1. Initiate a Conference Call:
Establish a connection with two or more parties
Press CONF button
Choose the desired line to join the conference by pressing the corresponding LINE button.
Repeat previous two steps for all other parties that would like to join the conference. This
can be done at any time. However, if a new call comes in, the other calls will be placed on
hold and the host will have to individually re-join the held lines back into the conference by
repeating the previous two steps again.
2. Cancel Conference: Canceling establishing conference call.
If after pressing the “CONF” button, a user decides not to conference anyone, press CONF
again or the original LINE button.
This will resume two-way conversation.
3. End Conference:
Press HOLD to end the conference call and put all parties on hold;
To speak with an individual party, select the corresponding blinking LINE.
NOTE: The party that starts the conference call has to remain in the conference for its entire duration, you
can put the party on mute but it must remain in the conversation. Also, this is not applicable when the feature
“Transfer on call hangup” is turned on.
Voice Messages (Message Waiting Indicator)
A blinking red MWI (Message Waiting Indicator) indicates a message is waiting. Press the MSG button to
retrieve the message. An IVR will prompt the user through the process of message retrieval. Press a
specific LINE to retrieve messages for a specific line account.
NOTE:
Each line has a separate voicemail account. Each account requires a voicemail portal number to be
configured in the “voicemail user id” field.
To check which line account has a message 1) press the message button (this always checks the
primary account), 2) check each line for stutter tone or 3) check missed calls using the menu.
Busy Lamp Field
The Multi Purpose Key buttons can be configured for Busy Lamp Field function with a specified account.
When BLF is configured on one of the multi-functional buttons, the Speed Dial function will work when that
line is not in use. Call Pick Up is supported when user presses a flashing BLF key.
Shared Call Appearance (SCA)
The GXP21xx phone supports shared call appearance by Broadsoft standard. This feature allows members
of the SCA group to shared SIP lines and provides status monitoring (idle, active, progressing, hold) of the
shared line. When there is an incoming call designated for the SCA group, all of the members of the group
will be notified of an incoming call and will be able to answer the call from the phone with the SCA extension
registered.
All the users that belong to the same SCA group will be notified by visual indicator when a user seizes the
line and places an outgoing call, and all the users of this group will not be able to seize the line until the line

Grandstream Networks, Inc. GXP21xx User Manual Page 20 of 42
Firmware 1.0.1.26 Last Updated: 11/2010
goes back to an idle state or when the call is placed on hold. (With the exception of when multiple call
appearances are enabled on the server side).
In the middle of the conversation, there are two types of hold: Public Hold and Private Hold. When a member
of the group places the call on public hold, the other users of the SCA group will be notified of this by the red-
flashing button and they will be able to resume the call from their phone by pressing the line button. However,
if this call is placed on private-hold, no other member of the SCA group will be able to resume that call.
To enable shared call appearance, the user would need to register the shared line account on one of the
accounts on the phone. In addition, they would need to navigate to “Settings”->”Basic Settings”on the web
UI and set the line to “Shared Line”with the corresponding account. If the user requires more shared call
appearances, the user can configure multiple line buttons to be “shared line”buttons associated with the
account.