Product name:IP phone Model name:GXP1760W Brand name:Grandstream Grandstream Networks, Inc.
COPYRIGHT ©2017 Grandstream Networks, Inc. http://www.grandstream.com All rights reserved. Information in this document is subject to change without notice. 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. The latest electronic version of this guide is available for download here: http://www.grandstream.
GNU GPL INFORMATION GXP1760W firmware contains third-party software licensed under the GNU General Public License (GPL). Grandstream uses software under the specific terms of the GPL. Please see the GNU General Public License (GPL) for the exact terms and conditions of the license. Grandstream GNU GPL related source code can be downloaded from Grandstream web site from: http://www.grandstream.
Table of Contents CHANGE LOG ................................................................................................................ 6 Firmware Version 1.0.0.93 ..................................................................................................................... 6 GUI INTERFACE EXAMPLES ........................................................................................ 7 WELCOME ...................................................................................................
Configuring Eventlist BLF .................................................................................................................... 55 Configuring VPK Keys ......................................................................................................................... 55 Outbound Notification Support ............................................................................................................. 55 UPGRADING AND PROVISIONING .................................................
Table of Tables Table 1: GXP1760W Features at a Glance ................................................................................................... 9 Table 2: GXP1760W Technical Specifications ............................................................................................ 10 Table 3: Configuration Menu ....................................................................................................................... 12 Table 4: Status Page Definitions ................................
CHANGE LOG This section documents significant changes from previous versions of administration guide for GXP1760W. Only major new features or major document updates are listed here. Minor updates for corrections or editing are not documented here. Firmware Version 1.0.0.93 • This is the initial version for GXP1760W.
GUI INTERFACE EXAMPLES http://www.grandstream.com/sites/default/files/Resources/gxp17xx_web_gui.zip 1. Screenshots of Login Page. 2. Screenshots of Status Pages. 3. Screenshots of Accounts Pages. 4. Screenshots of Settings Pages. 5. Screenshots of Network Pages. 6. Screenshots of Maintenance Pages. 7. Screenshots of Phonebook Pages.
WELCOME Thank you for purchasing Grandstream GXP1760W mid-range Wifi HD IP phones. The GXP1760W is a mid-range Wifi HD IP phone with a new sleek design and moderatecall-volume features. It comes equipped with integrated dual-band WiFi and 6 lines, 3 SIP accounts, 6 dual-color line keys and 4 XML programmable context sensitive soft keys on a 200 x 80 pixel back-lit LCD display screen.
PRODUCT OVERVIEW Feature Highlights The following table contains the major features of the GXP1760W: Table 1: GXP1760W Features at a Glance GXP1760W 6 lines 200*80-pixel backlit LCD display 4 XML programmable Softkeys 8 Dedicated function Keys 5-way conference Page | 9 GXP1760W Administration Guide
GXP1760W Technical Specifications The following table defines all the technical specifications including the protocols / standards supported, voice codecs, telephony features, languages and upgrade/provisioning settings for GXP1760W. Table 2: GXP1760W Technical Specifications Protocols/Standards SIP RFC3261, TCP/IP/UDP, RTP/RTCP, HTTP/HTTPS, ARP, ICMP, DNS (A record, SRV, NAPTR), DHCP, PPPoE, TELNET, TFTP, NTP, STUN, SIMPLE, LLDP, LDAP, TR-069, 802.1x, TLS, SRTP, IPv6.
Package weight: 1.55kg. Temperature and Operation: 0°C to 40°C. Humidity Storage: Humidity: Package Content -10°C to 60°C. 10％ to 90% Non-condensing. GXP1760W phone, handset with cord, base stand, universal power supply, network cable, Quick Installation Guide, GPL license. Compliance FCC: Part 15 (CFR 47) Class B. CE: EN55022 Class B, EN55024 Class B, EN61000-3-2, EN61000-3-3, EN60950-1. RCM: AS/ACIF S004, AS/NZS CISPR22/24, AS/NZS 60950.
CONFIGURATION GUIDE The GXP1760W can be configured via two ways: • LCD Configuration Menu using the phone's keypad. • Web GUI embedded on the phone using PC's web browser. Configuration via Keypad To configure the LCD menu using phone's keypad, follow the instructions below: • Enter MENU options: When the phone is in idle, press the round MENU button to enter the configuration menu. • Navigate in the menu options: Press the arrow keys up/down/left/right to navigate in the menu options.
• Local Phonebook • Local Group • Broadsoft Phonebook • LDAP Directory User may configure phonebooks/groups/LDAP options here, transfer phonebook XML to the phone, and search phonebook/LDAP directory. Messages Message sub menu include the following options: • Instant Messages Displays or clears all received instant messages. • Voice Mails Displays voicemail message information in the format below: new messages/all messages (urgent messages/all urgent messages).
• Date Time Configures time zone, date and time display format and NTP server on the phone. • Security Configures the available security settings (Config via keypad menu, web access mode, disable SSH). • Headset Type Selects headset types. • Star Key Lock Turns on/off keypad lock feature and configures keypad lock password. The default keypad lock password is null. If user enabled Star Key Lock without configuring password, user can unlock keypad by holding * key 4 seconds and pressing “OK” button.
o 802.1X Enables/Disables 802.1X mode, Configures 802.1x identity and MD5 password. o Layer 2 QoS Configures LAN port 802.1Q/VLAN Tag and priority value. Select “Reset Vlan Config” to reset VLAN configuration on the LAN port. o PC Port Mode Selects PC port mode (Enabled/Disabled/Mirrored). Configures PC port 802.1Q/VLAN Tag and priority value. o OpenVPN® Settings Enable/Disable OpenVPN®, configure OpenVPN® server and port.
o Diagnostic Mode All LEDs will light up. Toggle the line keys LED color to green with “#” and to red with “*”. Press any key on the phone to diagnose the key’s function. The key’s name will display on the LCD. Press the menu button or onhook/offhook handset to exit the diagnostic mode. o Keyboard Diagnostic All keys’ names will display on LCD screen before diagnosing. Press each key on the phone to remove it from the list of remaining keys to be diagnosed.
The following diagram shows the keypad MENU configuration flow: Call History Local Call Log Broadsoft Call Log Enable DND Disable DND Status Phone Book Messages Preference Direct IP Call Phone System Network Status Account Status System Status Local Phonebook Local Group Broadsoft Phonebook LDAP Directory Instant Messages Voice Mails Do Not Disturb Ring Tone Ring Volume LCD Contrast LCD Brightness Download SCR XML Erase Custom SCR Display Language Date and Time Security Headset Type Star key Lo
Configuration via Web Browser The GXP1760W embedded Web server responds to HTTP/HTTPS GET/POST requests. Embedded HTML pages allow a user to configure the IP phone through a Web browser such as Google Chrome, Mozilla Firefox and Microsoft’s IE. To access the Web GUI: 1. Connect the computer to the same network as the phone. 2. Make sure the phone is turned on and shows its IP address. You may check the IP address by pressing up arrow button when phone is at idle state. 3.
Definitions This section describes the options in the phone's Web GUI. As mentioned, you can log in as an administrator or an end user. • Status: Displays the Account status, Network status, and System Info of the phone. • Account: To configure the SIP account. • Settings: To configure call features, ring tone, audio control, LCD display, date and time, Web services, XML applications, programmable keys, etc. • Network: To configure network and WiFi settings.
NAT Traversal Displays the status of NAT connection for each account on the phone. Status System Info Product Model Product model of the phone. Part Number Product part number. Software Version • Boot: boot version number. • Core: core version number. • Base: base version number. • Prog: program version number. This is the main firmware release number, which is always used for identifying the software system of the phone. IP Geographic Information • Locale: locale version number.
Configures user account information provided by your VoIP service provider SIP User ID (ITSP). It's usually in the form of digits similar to phone number or actually a phone number. Authenticate ID Authenticate Password Name Configures the SIP service subscriber's Authenticate ID used for authentication. It can be identical to or different from the SIP User ID. Configures the account password required for the phone to authenticate with the ITSP (SIP) server before the account can be registered.
Determines a SIP Extension to notify the SIP server that the phone is behind a Proxy-Require NAT/Firewall. Do not configure this parameter unless this feature is supported on the SIP server. Account x SIP Settings Basic Settings Determines if the phone has an assigned PSTN telephone number. This field should be set to "User=Phone", so that "User=Phone" parameter will be TEL URI attached to the Request-Line and "TO" header in the SIP request to indicate the E.164 number.
SIP T1 Timeout is an estimate of the round-trip time of transactions between a SIP T1 Timeout client and server. If no response is received the timeout is increased, and request re-transmit retries would continue until a maximum amount of time define by T2. The default setting is 0.5 seconds. SIP T2 Timeout is the maximum retransmit time of any SIP request messages SIP T2 Timeout (excluding the INVITE message). The re-transmitting and doubling of T1 continues until it reaches the T2 value.
If set to “Yes”, the Privacy Header will always be shown on the INVITE. If set to “No”, the Privacy Header won’t be shown on the INVITE. Default setting is “Default”. Controls whether the P-Preferred-Identity Header will present in the SIP INVITE Use P-PreferredIdentity Header message. The default setting is “default”. The P-Preferred-Identity Header will show in INVITE unless “Huawei IMS” special feature is on. If set to “Yes”, the P-Preferred-Identity Header will always show in INVITE.
Different soft switch vendors have special requirements. Therefore, users may need select special features to meet these requirements. Users can choose Special Feature from Standard, Nortel MCS, Broadsoft, CBCOM, RNK, Sylantro, Huawei IMS and PhonePower depending on the server type. The default setting is "Standard". Default setting is "No". When set to "Yes", a softkey “BSCCenter” is displayed Broadsoft Call on LCD.
If Force Timer is set to “No”, the phone will enable the session timer only when the remote party supports this feature. To turn off the session timer, select “No”. The default setting is “No”. UAC Specify As a Caller, select UAC to use the phone as the refresher, or select UAS to use Refresher the Callee or proxy server as the refresher. The default setting is “Omit”.
SRTP Mode Enable SRTP mode based on your selection from the drop-down menu. The default setting is “Disabled”. Enable or disable the crypto life time when using SRTP. If users set to disable Crypto Life Time this option, phone does not add the crypto life time to SRTP header. The default setting is “Yes”. Symmetric RTP Defines whether symmetric RTP is supported or not. The default setting is “No”. Controls the silence suppression/VAD feature of the audio codec G.729.
Account x Call Settings Selects whether or not to enable early dial. If set to "Yes", the SIP proxy must support 484 responses. Early Dial means that the phone sends for each Early Dial pressed digit a SIP INVITE message to SIP server. SIP server looks into its extensions and, if no match happened yet, it sends back a "484 Address Incomplete" message. Otherwise, it executes the action. Default setting is "No". Dial Plan Prefix Configures the prefix to be added to each dialed number.
• Example 5: If we set the dial plan with {\$123}, it should allow input $123 to pass dial plan check. • Example 6: If we set the dial plan with {12\_3}, it should allow input 12_3 to pass dial plan check. Example of a simple dial plan used in a Home/Office in the US: { ^1900x. | <=1617>[2-9]xxxxxx | 1[2-9]xx[2-9]xxxxxx | 011[2-9]x. | [3469]11 } Explanation of example rule (reading from left to right): • ^1900x.
Selects the distinctive ring tone for the matching rule. When the incoming caller ID or Alert Info matches the rule, the phone will ring with the selected ring. Ring Timeout Defines the timeout (in seconds) for the rings on no answer. The default setting is 60. The valid range is from 10 to 300. If set to "Yes", the "From" header in outgoing INVITE messages will be set to Send Anonymous anonymous, essentially blocking the Caller ID to be displayed. The default setting is "No".
Do Not Disturb (DND)--On Do Not Disturb (DND)--Off Configures DND feature code to turn on DND. Configures DND feature code to turn off DND. Delayed Call Defines the timeout (in seconds) before the call is forwarded on no answer. The Forward Wait Time default value is 20 seconds. The valid range is 1 to 120. Settings Page Definitions Table 6: Settings Page Definitions Settings General Settings This parameter defines the local RTP port used to listen and transmit.
Disable Busy Tone on Remote Disconnect Disable Direct IP Call Disable the busy tone heard in the handset when call is disconnected remotely. The default setting is “No”. Disables Direct IP Call. The default setting is "No". When set to "Yes", users can dial an IP address under the same LAN/VPN segment by entering the last octet in the IP address. To dial quick IP call, off hook Use Quick IP Call mode the phone and dial #XXX (X is 0-9 and XXX <=255), phone will make direct IP call to aaa.bbb.ccc.
Return Code When Refusing Incoming Send selected type of SIP message to the call when refusing the incoming call. Call Return Code When Enable DND Send selected type of SIP message when enabling DND. Local Call Enables/Disables the ability to record calls locally while on the call screen. The Recording Feature default setting is "Disabled" Saved Local Call Defines the location where the recordings will be stored, either on the internal Recording Location storage or on the connected USB.
• Message Waiting (Frequencies are in Hz and cadence on and off are in 10ms) • Ring Back Tone ON is the period of ringing (“On time” in ‘ms’) while OFF is the period of silence. • Call-Waiting Tone • Busy Tone • Reorder Tone To set a continuous ring, OFF should be zero. Otherwise it will ring ON ms and a pause of OFF ms and then repeat the pattern. Up to three cadences are supported. Call Waiting Tone This adjusts the call waiting tone volume. Gain Users can select “Low”, “Medium” or “High”.
Headset RX gain Configures the receiving gain of the headset. The default value is 0dB. Handset TX gain Configures the transmission gain of the handset. The default value is 0dB. Settings LCD Display Backlight Configures the LCD brightness when the phone is active. Valid range is 10 to 100 Brightness: Active where 100 is the brightest. Default value is 100. Backlight Configures the LCD brightness when the phone is idle.
• dd-mm-yyyy: 02-07-2012 • dddd, MMMM dd: Friday, October 12 • MMMM dd, dddd: October 12, Friday Time Display Configures the time display in 12-hour or 24-hour format on the LCD. The default Format setting is in 12-hour format. Settings Web Service Use Auto Location Service Enables/disables auto location services on the phone. Default setting is “Yes”. Settings XML Application Idle Screen XML Configures to enable idle screen XML download.
• Busy Lamp Field (BLF) Select the Account to monitor the BLF status. Enter the extension number in the Value field to be monitored. • Presence Watcher This option has to be supported by a presence server and it is tied to the "Do Not Disturb" status of the phone's extension. • Eventlist BLF This option is similar to the BLF option but in this case the PBX collects the information from the phones and sends it out in one single notify message. PBX server has to support this feature.
• LDAP Search This option is to narrow the LDAP search scope. Enter the LDAP search base in the Description field. It could be the same or different from the Base in LDAP configuration under Advanced Settings. The Base in LDAP configuration will be used if the Description field is left blank. Enter the LDAP Name/Number filter in the Value field.
• Voice Mail Select Account and enter the Voice Mail access number in the Value field. • Call Return The last answered calls can be dialed out by using Call Return. The Value field should be left blank. Also, this option is not binding to the account and the call will be returned based on the account with the last answered call. • Intercom Select Account, and enter the extension number in the Value field to do the intercom. • LDAP Search This option is to narrow the LDAP search scope.
For instance, “https://SERVER_URI”. • Port Configure the BroadWorks Xsi server port. The default port is 80. If the server uses HTTPS, please configure 443. • XSI Authentication Type Select the authentication type to use to authenticate against the Broadsoft server. User can choose the Login credentials, SIP Credentials or use the existing Accounts to authenticate. • Login Username Configure the Username for the BroadWorks XSI feature.
• Personal Directory Enable/Disable and rename the BroadWorks XSI Personal Directory features on the phone. If keep the Name box blank, the phone will use the default name “Personal” for it. • Missed Call Log Enable/Disable and rename the BroadWorks XSI Missed Call Log features on the phone. If keep the Name box blank, the phone will use the default name “Missed” for it. • Placed Call Log Enable/Disable and rename the BroadWorks XSI Placed Call Log features on the phone.
from computer. If enabled, a reboot is required to establish the communication. Default is “Disabled”. GS Affinity CTI Application is available HERE and its User Guide from HERE. Preferred Account Chooses the account on which CTI support is enabled. Network Page Definitions Table 7: Network Page Definitions Network Basic Settings Internet Protocol IPv4 Address Selects IPv4 Only, IPv6 Only or Both IPv4 & IPv6. Default setting is “IPv4 Only”.
IPv6 address type. DNS Server 1 Enter the DNS Server 1 for IPv6. DNS Server 2 Enter the DNS Server 2 for IPv6. Preferred DNS server Enter the Preferred DNS Server for IPv6. Network Advanced Settings Allows the user to enable/disable 802.1X mode on the phone. The default value 802.1X mode is disabled. To enable 802.1X mode, this field should be set to EAP-MD5, users may also choose EAP-TLS, or EAP-PEAP. 802.1X Identity Enter the Identity information for the 802.1x mode.
Address OpenVPN® Port Specifies the listening port of the OpenVPN® server. Default is 1194. OpenVPN® Specifies the Transport Type of OpenVPN® whether UDP or TCP. Default is Transport UDP. OpenVPN® CA Uploads the Certification Authority of OpenVPN®. For a new upload, users could click on “Delete” to erase the last certificate, and then upload a new one. OpenVPN® Click on “Upload” to upload OpenVPN® certificate.
Before Challenge before being challenged by the server. The default setting is “No”. Default setting is “Yes”. DHCP option 66 originally was only designed for TFTP Allow DHCP Option server. And then was extended to support an HTTP URL. 43 and Option 66 GXP phones support both TFTP and HTTP server via option 66. Users can Override Server also use DHCP option 43 vendor specific option to do this. DHCP option 43 approach has priorities.
Password OpenSSL. This is required for the phone to decrypt the encrypted XML configuration file. Authenticate Conf File Download Device Configuration Upload Device Configuration Authenticates configuration file before acceptance. Default setting is "No". Click to download phone’s configuration file in .txt format. Upload configuration file to phone. Firmware Upgrade Allows users to choose the firmware upgrade method: TFTP, HTTP or HTTPS. Via The default setting is “HTTP”.
Send SIP Log Configures whether the SIP log will be included in the syslog messages. The default setting is "No". Auto Recover From If set to “Yes”, the phone will automatically recover when running abnormal. Abnormal The default setting is “Yes”. Maintenance Language Selects display language on the phone. There are 21 languages can be set as Display Language display language, user could also choose “Auto” or “Downloaded Language” as display language. The default setting is “Auto”.
Upgrade and Factory Reset options under System submenu, and SIP option under Phone submenu as well. If set to "Yes", the keypad can be locked by pressing and holding the STAR * Enable STAR key Keypad Locking key for about 4 seconds. A lock icon will show indicating the keypad is locked. The default setting is "Yes". Note: When the keypad is locked, users would need press and hold the STAR * key for about 4 seconds again and then enter the password to unlock it.
Phonebook Group Management Add Group Specifies Group’s name to add new group. Edit Group Edits selected group. Phonebook Phonebook Management Enable Phonebook Configures XML Download HTTP/HTTPS/TFTP to download the phonebook file. Default setting is "Disabled". HTTP/HTTPS User Name HTTP/HTTPS Password to enable phonebook XML download. Users could select The user name for the HTTP/HTTPS server. The password for the HTTP/HTTPS server.
Password Configures the bind "Password" for querying LDAP servers. The field can be left blank if the LDAP server allows anonymous binds. Configures the filter used for number lookups. Examples: LDAP Number Filter (|(telephoneNumber=%)(Mobile=%) returns all records which has the with the "telephoneNumber" or "Mobile" field starting with the entered prefix. (&(telephoneNumber=%) (cn=*)) returns all the records "telephoneNumber" field starting with the entered prefix and "cn" field set.
Sort Results Specifies whether the searching result is sorted or not. Default setting is "No". LDAP Lookup Configures to enable LDAP number searching when dialing and receiving calls. Configures the display name when LDAP looks up the name for incoming call or Lookup Display Name outgoing call. This field must be a subset of the LDAP Name Attributes.
Using the Keypad Menu To connect the GXP1760W to WiFi Network through the keypad menu. Please refer to following steps: 1. On LCD menu, navigate to System Network WiFi settings and enable WiFi. 2. Select “Scan” and GXP1760W will automatically start scanning within the range. 3. A list of WiFi networks will be displayed. Select the desired network, and if required, enter the correct password to connect.
Editing Contacts and Click-To-Dial From GXP1760W Web GUI, users could view contacts, edit contacts, or dial out with Click-to-Dial feature on the top of the Web GUI. In the following figure, the Contact page shows all the added contacts (manually or downloaded via XML phonebook). Here users could add new contact, edit selected contact, or dial the contact/number. Before using the Click-To-Dial feature, make sure the option "Click-To-Dial Feature" under web GUISettingsCall Features is turned on.
Figure 5: Click-to-Dial Saving Configuration Changes After users makes changes to the configuration, press the "Save" button will save but not apply the changes until the "Apply" button on the top of web GUI page is clicked. Or, users could directly press "Save and Apply" button. We recommend rebooting or powering cycle the phone after applying all the changes. Rebooting from Remote Locations Press the "Reboot" button on the top right corner of the web GUI page to reboot the phone remotely.
Note: - User can also define whether RTP packets will be captured or not using With RTP Packets option. - USB Filename is only required for USB and it defines the capture filename. Multicast Paging GXP1760W supports multicast paging, including sending and listening. On the phone, users could send multicast page by setting the multicast address and port. Also, users can listen to at most 10-different multicast IP address. Multicast sender related settings are under Web UI, SettingsProgrammable keys.
Figure 7: Action URL Settings Page Table 10: Action URL - Supported Events Supported Events P Values Setup Completed P8304 Registered P8305 Unregistered P8306 Off Hook P8308 On Hook P8309 Incoming Call P8310 Outgoing Call P8311 Valid Format String P a g e | 56 GXP1760W Administration Guide
Missed Call P8312 Established Call P8313 Terminated Call P8314 Open DND P8316 Close DND P8317 Open Forward P8318 Close Forward P8319 Blind Transfer P8320 Attended Transfer P8321 Hold Call P8324 UnHold Call P8325 Table 11: Action URL – Supported Dynamic Variables Supported Dynamic Variables Dynamic Variable Description $phone_ip The IP address of the phone. $mac The MAC address of the phone. $product The product name of the phone.
During incoming call, outgoing call and call hold, capture the trace on the phone and check the packets. We can see the phone send Action URL with actual values to SIP server to notify phone events. In the following screenshot, from top to bottom, the phone events for each HTTP message are: Incoming Call, hold call and Outgoing Call in the format of the defined action URL with the parameters replaced with actual values.
UPGRADING AND PROVISIONING The GXP1760W 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 FQDN or IP address. Examples of valid URLs: firmware.grandstream.com fw.ipvideotalk.com/gs There are two ways to setup a software upgrade server: The LCD Keypad Menu or the Web Configuration Interface.
Firmware upgrading takes around 60 seconds in a controlled LAN or 5-10 minutes over the Internet. We recommend completing firmware upgrades in a controlled LAN environment whenever possible. No Local TFTP/HTTP Servers For users that would like to use remote upgrading without a local TFTP/HTTP server, Grandstream offers a NAT-friendly HTTP server. This enables users to download the latest software upgrades for their phone via this server. Please refer to the webpage: http://www.grandstream.
Configuration File Download Grandstream SIP Devices can be configured via the Web Interface as well as via a Configuration File (binary or XML) through TFTP or HTTP/HTTPS. The "Config Server Path" is the TFTP or HTTP/HTTPS server path for the configuration file. It needs to be set to a valid URL, either in FQDN or IP address format. The "Config Server Path" can be the same or different from the "Firmware Server Path".
RESTORE FACTORY DEFAULT SETTINGS Warning: Restoring the Factory Default Settings will delete all configuration information on the phone. Please backup or print all the settings before you restore to the factory default settings. Grandstream is not responsible for restoring lost parameters and cannot connect your device to your VoIP service provider. Please follow the instructions below to reset the phone: 1. Press MENU button to bring up the keypad configuration menu. 2. Select "System" and enter. 3.
EXPERIENCING THE GXP1760W Please visit our website: http://www.grandstream.com to receive the most up- to-date updates on firmware releases, additional features, FAQs, documentation and news on new products. We encourage you to browse our product related documentation, FAQs and User and Developer Forum for answers to your general questions. If you have purchased our products through a Grandstream Certified Partner or Reseller, please contact them directly for immediate support.
FCC Caution. This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Any Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.
