Grandstream Networks GSC35 Series User manual

Grandstream Networks, Inc.
GSC35xx Series
GSC3516 – User Manual

● Up to 16 SIP accounts.
● Ethernet RJ45 10/100Mbps, PoE/PoE+, Integrated Bluetooth, Wi-Fi.
● 2-way voice functionality with both a high-fidelity 15W HD speaker and 3
directional microphones with Multichannel Microphone Array Design
(MMAD) and 1 omnidirectional auxiliary microphone that offer a 4.2 meter
pickup distance
GSC3516
WELCOME
The GSC3516 is a SIP intercom speaker and microphone that allows offices, schools, hospitals, apartments and more to build
powerful voice intercom solutions that expand security and communication. This robust SIP intercom device offers 2-way
voice functionality with both a high fidelity 15W HD speaker and 3 directional microphones with Multichannel Microphone
Array Design (MMAD) and 1 omnidirectional auxiliary microphone that offer a 4.2 meter pickup distance. The GSC3516
supports a wide-range of peripherals including Bluetooth devices, built-in whitelist and blacklists to easily block unwanted
calls, integrated dual-band Wi-Fi and advanced acoustic echo cancellation. By pairing the GSC3516 with other Grandstream
devices, including desktop and cordless IP phones as well as the GDS series of Facility Access products, users can easily sculpt
a state-of-the-art security and voice intercom solution. Thanks to it’s modern industrial design, cleanable exterior surface and
rich features, the GSC3516 is the ideal intercom speaker/microphone for any setting.
PRODUCT OVERVIEW
Feature Highlights
The following table contains the major features of the GSC3516:
Table 1: GSC3516 Features in a Glance
GSC3516 Technical Specifications
The following table resumes all the technical specifications including the protocols / standards supported, voice codecs,
telephony features, languages and upgrade/provisioning settings for GSC3516.
Protocols/Standards
SIP RFC3261, TCP/IP/UDP, RTP/RTCP, RTCP-XR,HTTP/HTTPS, ARP,
ICMP, DNS (A record, SRV, NAPTR), DHCP, PPPoE, SSH, TFTP, NTP,
STUN, LLDP-MED, SIMPLE, LDAP,TR-069, 802.1x, TLS, SRTP, IPv6,
OpenVPN®
Network Interfaces
One 10/100 Mbps port with integrated PoE/PoE+
Operating System
Linux
Bluetooth
Yes, integrated. Bluetooth 2.1+Enhanced Data Rate (EDR)+ BT4.2
Wi-Fi
Yes, dual-band 2.4 & 5GHz with 802.11 a/b/g/n/ac
Auxiliary Port
One 2-pin multi-purpose input port, Reset
Voice Codecs and
Capabilities
G.711µ/a, G.722 (wide-band), G.726-32, iLBC, Opus, G.723, G.729A/B, in-band and out-ofband DTMF (In
audio, RFC2833, SIP
INFO), VAD, CNG, AEC, PLC, AJB, AGC, ANS

Telephony Features SIP Paging, Multicast Paging，Group Paging, PTT, Call-waiting with
priority override, Bluetooth SCO call
HD Audio
Yes, HD speakerphone with support for full band audio with 48KHz
voice sampling frequency
Speaker
15W high-fidelity HD speaker
Frequency: 100Hz-20000 Hz
Volume: Up to 90 dBA at 1W power at 0.5 meter
Microphones
3 directional microphones with beam-forming capability and up to 4.2-meter voice pickup distance and 1
omnidirectional auxiliary
microphone
QoS
Layer 2 QoS (802.1Q, 802.1p) and Layer 3 (ToS, DiffServ, MPLS) QoS
Security
User and administrator level passwords, MD5 and MD5-sess based
authentication, 256-bit AES encrypted configuration file, TLS, SRTP,
HTTPS, 802.1x media access control,secure boot
Multi-language(TBD)
English, German, French, Spanish, Portuguese, Russian & Chinese
Upgrade/Provisioning
Firmware upgrade via TFTP / HTTP / HTTPS or local HTTP upload,
mass provisioning using GDMS/TR069 or AES encrypted XML
configuration file
Power & Green
Energy Efficiency
Integrated PoE* 802.3af Class 3, PoE+ 802.3at Class 4
Temperature and
Humidity
● Operation: 0°C to 40°C
● Storage: -10°C to 60°C
● Humidity: 10% to 90% Non-condensing
Package Content
● GSC3516 SIP Intercom Speaker/Microphone
● Mounting kits
● Quick installation guide
Compliance(TBD)
● FCC: Part 15 (CFR 47) Class B; UL 60950 (power adapter); FCC Part
15C, FCC Part 15E, MPE
● CE: EN 55032; EN 55024; EN 61000-3-2; EN 61000-3-3; EN 60950-1;
EN 301 489-1/17; EN 300 328; EN 301 893; EN 62311; RoHS
● RCM: AS/NZS CISPR 32/24; AS/NZS 60950.1; AS/NZS 4268
● IC: ICES 003, RSS 247, RSP-100, RSS 102
Table 2: GSC3516 Technical Specifications
GETTING STARTED
This chapter provides basic installation instructions including the list of the packaging contents and also information for
obtaining the best performance with the GSC3516.
Equipment Packaging

Figure 1: GSC3516 Package Content
1x GSC3516 Main Case.
1x Metal Bracket
1x Plastic Bracket
Hang rope plate
4x Screw (PM 3x50)
3x Screw (PA 3.5x20)
Wiring Seat
3x Plastic Expansion Bolt
3x M3 NUT
1x Quick Installation Guide
Table 3: Equipment Packaging
Note
Check the package before installation. If you find anything missing, contact your system administrator.
GSC3516 Ports

Figure 2: GSC3516 Ports
1
2-PIN Port
2-PIN Multi-Purpose Input Port.
2
NET/PoE
Ethernet RJ45 port (10/100Mbps) supporting PoE/PoE+.
3
RESET
Factory reset pinhole.
Press for 10 seconds to reset factory default settings.
Table 4: Ports Description
LED Indicators
The GSC3516 contains 4 types of colored LEDs (Red, Green, White and Blue light) that are used in some specific situations and
operations. Please, refer to the following table describing each one of the LED Indicators status:
Color
LED Indicator Status
Description
Red Light
Fast Flashing (every 1s)
Rebooting/factory resetting
Slow Flashing (On 1s, Off 2s)
Unhandled event: (Included Missed call(s), new voice mails, new SIP messages).
Note: In case it's connected via Bluetooth, Missed Call/Voicemail Red LED will not
light and will remain flashing in blue.
Solid Red
The contacts/storage space is full
Green Light
Fast Flashing (every 1s)
Incoming/outgoing call
Slow Flashing (On 1s, Off 2s)
Call on hold.
Solid Green
During the call.
White Light
Fast Flashing (every 1s)
Upgrading the firmware.
Blue Light
Fast Flashing (every 1s)
Bluetooth pairing.
Table 5: LED Indicators
Hardware Installation
GSC3516 can be mounted on the wall or ceiling. Please refer to the following steps for the appropriate installation
Wall Mount

1. Locate the equipment holder on the desired position with arrow up. Drill three holes on the wall referring to the positions
of holes on the metal bracket.
2. Fix the metal bracket on the wall by expansion screws.
3. Align the position line on device’s back cover with the positioning slot.
4. Rotate the device clockwise until it is locked on the right position.
Figure 3: Wall Mount
Ceiling Mount
1. Put the ceiling mounting (metal bracket) in the ceiling’s center and mark the position of the three screws holes.
2. Drill a round hole with a diameter of 18mm for Ethernet cable. The distance between its center and the highlighted hole
on the plastic bracket should be 35mm.
3. Fix the plastic and metal brackets on the ceiling with flat-head screws and locknuts. Then place and Ethernet cable pass
through the 18mm-round hole.
4. Align the position line on device’s back cover with the positioning slot.
5. Rotate the device clockwise until it is locked on the right position.
Figure 4:Ceiling Mount
Anti-theft Installation
After the device is assembled with the metal bracket support on the wall or ceiling, use the anti-detachable screw (M3 x 50) in
order to prevent theft.
Figure 5: Anti-theft Installation
Powering and Connecting GSC3516
The GSC3516 can be powered on using PoE/PoE+ switch or PoE injector using following steps:

Step 1: Plug a RJ45 Ethernet cable into the network port of the GSC3516.
Step 2: Plug the other end into the power over Ethernet (PoE) switch or PoE injector.
Figure 6: Powering GSC3516
Connecting Wiring Seat
GSC3516 support to connect a “Key & LED” or “Normal Key” to the 2-pin port via Wiring Seat using following steps:
Step 1: Take the wiring seat from the install kits.
Step 2: Connect the “Key & LED” or “Normal Key” with the wiring seat (as shown in the figure below)
Note: This port supports the parallel connection of an incandescent lamp (with less than 1W) or an LED lamp (with less than
100mA).
Figure 7: Connecting Wiring Seat
Access GSC3516 Web GUI
The GSC3516 embedded Web server responds to HTTP/HTTPS GET/POST requests. Embedded HTML pages allow users to
configure the application phone through a Web browser such as Microsoft’s IE, Mozilla Firefox, Google Chrome and etc.

Figure 8: GSC3516 Web GUI – Login
Users can use a computer connected to the same network as the GSC3516 to discover and access the GSC3516 Configuration
Interface using its MAC Address.
Please, refer to the following steps in order to access the GSC3516 Web GUI:
1. Locate the MAC address on the MAC tag of the unit, which is on the underside of the device, or on the package.
2. From a computer connected to same network as the GSC3516, type in the following address using the GSC3516’s MAC
address on your browser: https://gsc_<mac>.local
Example: if a GSC3516 has the MAC address C0:74:AD:xx:xx:xx, this unit can be accessed by typing
https://gsc_c074adxxxxxx.local on the browser.
GSC3516 APPLICATION SCENARIOS
GSC3516 SIP Two-Way/One-Way Intercom System
GSC3516 can be used as an Intercom System using built-in SIP accounts, once the SIP account registered the device can
receive paging/intercom calls and it will automatically answer calls coming from whitelisted numbers.
To register a SIP account on the GSC3516 the user needs to go under Account 󰒇Account X 󰒇General Settings, and enter
the account information as below, then save and apply the configuration.

Figure 9: SIP Account Configuration
Once the account registered correctly, the GSC3516 will show the account status under Status Account Status.
Figure 10: SIP Account Status
By default, the GSC3516 Blocks non-whitelisted number under Calls →Blacklist/Whitelist/Greylist →Greylist, user needs to
either allow Non-White list calls or to set up a Whitelist that contains the number that will be allowed to call the GSC3516.
Figure 11: Greylist Calls
On the screenshot below, only number 1001 is allowed to call GSC3516:
󰒇

Figure 12: Whitelisted Devices
As soon as a SIP call is received by the GSC3516, first checks if the Caller ID number is allowed on the Whitelist and then
answers automatically.
Notes
GSC3516 is an intercom system and auto-answers all whitelisted numbers.
By default, GSC3516 plays a Warning tone when auto answering incoming calls, this warning tone can be disabled under
Account 󰒇Account X 󰒇Call Settings, “Play Warning Tone for Auto Answer Intercom”.
Multicast Paging Application
Multicast paging is an approach to let different SIP users to listen for paging calls from a common multicast IP address. In
multicast page call, an audio connection will be set up from sender to receiver, but the receiver will be only able to receive
audio, a one-way communication. The 2 entities, Sender/Receiver, must be located on same LAN (same broadcast domain).
To receive multicast page, GSC3516 must be well configured to listen to the right address and port. The configuration is
located under Phone Settings →Multicast/Group Paging. Up to 10 listening addresses are supported with priority levels
from 1 to 10.
Note: Multicast paging configuration requires a reboot to take effect.
Figure 13: Multicast Paging Listening Addresses
In above screenshot, Listening Address “237.11.10.11:6767” with label “Sales” has the highest priority.
Users can enable “Paging Priority Active” option (under Multicast Paging tab) to accept incoming paging calls during active
multicast paging. The paging call with higher priority than active one will be accepted.

Figure 14: Multicast Paging – Paging Priority Active
In the case of receiving a multicast paging call while on a unicast SIP call, the GSC3516 can choose to either keep the SIP call
or to hold this last and allow the multicast call depending on paging call priority.
This is can be set using “Paging Barge” option. If the option is set to “Disabled” all incoming multicast paging calls will be
dropped while on a SIP call. If the multicast paging call has higher priority than the value set on “Paging Barge”, the SIP call
will be put on hold and GSC3516 will the incoming multicast paging.
Figure 15: Multicast Paging – Priority Barge
Bluetooth Speaker
The GSC3516 can be used as a Bluetooth speaker for another device and it needs to be connected via Bluetooth to that
device. Users need to turn on GSC3516’s Bluetooth function first. The first time when using a new Bluetooth device with the
GSC3516, “pair” the device with GSC3516 so that both devices know how to connect securely to each other.

Figure 16: Connecting the GSC3516 as a Bluetooth Speaker
Please, refer to the following steps in order to pair and connect the GSC3516 to the device:
1. Go to GSC3516 Web GUI →Network Settings →Bluetooth.
2. Enable “Bluetooth” function, and enable the option “Discoverable to Nearby Bluetooth Devices” in order to make the
GSC3516 visible.
3. Go to your Device’s Bluetooth settings I order to search for visible devices. The GSC3516 is going to be listed within the
visible devices with the “Device Name” configured on the Web GUI.
4. Click on the GSC3516 device’s name in order to pair and connect it to the device.
Note
The GSC3516 will only play the role of a speaker when it is connected to another device via Bluetooth. Users cannot use the
GSC3516 to take control of calls made/received by the device connected to it.
2-pin Multi-Purpose Input Applications
GSC3516 supports 2-pin multi-purpose input that can connect a “Key with LED” or “Normal Key”. By configuring the sensor
settings users can enable the GSC3516 to play an audio file (.wav/.mp3 format), trigger a SIP call to a pre-configured
extension, or to start recording.
Figure 17: 2-pin Multi-Purpose Input Applications
To configure sensor settings, access to web UI →System Settings →Sensor Setting.

Figure 18: Sensor Settings
Under Basic Setting section, users can set “Sensor Type” and “Trigger Type”.
Two states are supported by the Input circuit for the “Sensor Type”:
1. Normally Open where the contact is disconnected when there is no electricity
2. Normally Close where the contact is connected when there is no electricity.
Users could set “Trigger Type” to:
1. Edge Triggered: When selected, the notification is triggered only when the level changes (high level to low level, or low
level to high level.
2. Level Triggered: When selected, only high level (1) will trigger the notification.
Under “Trigger time” section, users can click on “Add” in order to configure different schedules and a trigger profile for each
one as shown in the figure below:
Figure 19: Sensor Setting – Trigger time
Cycle Time: The alarm can be configured to be triggered all days of the week, in this case “All days” option needs to be
checked. Or to some specific days of the week with Start and End time, in this case “Period of Time” option needs to be

checked for users to be able to configure Time and Frequency options.
Play Audio: If checked, GSC3516 will play a sound when the switch is triggered during the schedule. Users can select a
“Prompt Tone” from available tones or upload a customized tone.
Figure 20: Sensor Setting – Linkage Function – Play Audio
Make Call: If checked, GSC3516 will dial out configured numbers on “Dial out extension” fields (up to 2 numbers
supported) when the switch is triggered during the schedule.
Figure 21: Sensor Setting – Linkage Function – Make Call
Recording: If selected, GSC3516 will record audio using built-in microphones.

Note
Up to 7 different Alarm Schedule/Linkage function can be configured in the GSC3516, the list of schedules and linkage functions
will be shown in the lower section of the page, users can edit or delete the Alarm schedule by clicking on Edit or Delete buttons
respectively.
GSC3516 WEB GUI SETTINGS
The GSC3516 embedded Web server responds to HTTP/HTTPS GET/POST requests. Embedded HTML pages allow users to
configure the application phone through a Web browser such as Microsoft’s IE, Mozilla ,Firefox, Google Chrome and etc.
Status Page Definitions
Account Status
Account
16 SIP accounts on the device
SIP User ID
SIP User ID for the account
SIP Server
SIP Server Address
Operation
Edit the account details.
Table 6: Account Status
Network Status
Network Status →Ethernet
LAN Port
Displays LAN Port connected or not and the speed
MAC Address
Global unique ID of device, in HEX format. The MAC address will be used for provisioning and can be
found on the label coming with original box and on the label located on the back of the device.
PPPoE Link Up
PPPoE status: Enabled or Disabled
IPv4
IPv4 Address Type
Configured IPv4 address type: DHCP, Static IP or PPPoE
IPv4 Address
IPv4 address of the device.
Gateway
Default gateway of the device.
IPv4 NAT Type
Type of IPv4 NAT connection used by the device.
IPv6
IPv6 Address Type
Configured IPv6 address type: DHCP, Static IP or PPPoE
Global Unicast Address
IPv6 address of the device.

Link-Local Address
Link-Local Address of the device
IPv6 Static Gateway
Default IPv6 gateway of the device.
IPv6 DUID
IPv6 DUID of the device.
IPv6 NAT Type
Type of IPv6 NAT connection used by the device.
Table 7: Status – Network Status – Ethernet page
Network Status →Wi-Fi
WLAN MAC Address
Device WLAN MAC Address
SSID
Displays the name of the SSID currently the device connected to
Country Code
The configured Country Code
IPv4
IPv4 Address Type
Configured IPv4 address type: DHCP, Static IP or PPPoE
IPv4 Address
IPv4 address of the device.
Gateway
Default gateway of the device.
IPv4 NAT Type
Type of IPv4 NAT connection used by the device.
IPv6
IPv6 Address Type
Configured IPv6 address type: DHCP, Static IP or PPPoE
Global Unicast Address
IPv6 address of the device.
Link-Local Address
Link-Local Address of the device
IPv6 Static Gateway
Default IPv6 gateway of the device.
IPv6 DUID
IPv6 DUID of the device.
IPv6 NAT Type
Type of IPv6 NAT connection used by the device.
Table 8: Status – Network Status – Wi-Fi page
Network Status →DNS & NAT
DNS Server
DNS Server x
DNS Server Address up to 4 address (ex: 8.8.8.8)
DNS Mode

Accounts x DNS Mode for each SIP Account up to 16 accounts: A Record, SRV, NAPTR/SRV, Use Configured IP
NAT Traversal
Accounts x
NAT Traversal for each SIP Account up to 16 accounts: No, STUN, Keep-Alive, UPnP, Auto, VPN (Auto is the default
settings)
Table 9: Status – Network Status – DNS & NAT page
System Info
System Info →Information
Product Model
Product model of the device: GSC3516
Part Number
Product part number
Software Version
Boot
Specifies Boot version
Core
Specifies Core version
Prog
Specifies Prog version. This is the main firmware release number, which is always used for
identifying the software system
Locate
Specifies Locale version
Res
Specifies Locale version
IP Geographic Information
Language
Specifies current language
Recommend Time Zone
Specifies Recommend Time Zone
System Time
System Up Time
System up time since the last reboot
System Time
Indicates Date and Time
System Time Zone
Indicates the Time Zone selected
PoE Detection
PoE Status
Indicates POE Status: Type and Max wattage
System Information
Download System Information
Click on "Downlod" to downlod a file containing all the system information

Table 10: System Info – Information page
System Info →Status
Service Status
gui
Indicates gui code
phone
Indicates phone code
cpe
Indicates cpe code
avs
Indicates avs code
User Space
User Space Used
Indicates User space used
Database Status
Indicates the status of the Database (ex: Normal)
Core Dump
Generate core dump
Click on (GUI, AVS, CPE, PHONE) to generate a core dump
Core Dump
Click on "Download" to download the generated core dump
Clear Core Dumps
Click on "Start" to clear Core Dumps files
Special Feature
OpenVPN® Support
Indicates the support of OpenVPN® (Yes)
Table 11: System Info – Status page
Account Page Definitions
GSC3516 has 16 independent SIP accounts. Each SIP account has an individual configuration page.
Accounts/General Settings
Account Register
Account Active
Indicates whether the account is active. 1st account active by default.
Account Name
Configures the name associated with each account.
IP Server
Specifies the URL or IP address, and port of the SIP server. This should be provided by VoIP service
provider (ITSP).
Secondary SIP Server
The URL or IP address, and port of the SIP server. This will be used when the primary SIP server fails.
Outbound Proxy
Configures the IP address or the domain name of the primary outbound proxy, media gateway or

session border controller. It’s used by the device for firewall or NAT penetration in different network
environments. If a symmetric NAT is detected, STUN will not work and only an outbound proxy can
provide a solution
Secondary Outbound Proxy
Sets IP address or domain name of the secondary outbound proxy, media gateway or session border
controller. The device will try to connect the Secondary outbound proxy only if the primary outbound
proxy fails.
SIP User ID
Configures user account information provided by your VoIP service provider (ITSP). It’s usually in the
form of digits similar to phone number or actually a phone number.
SIP Authentication ID
Configures the SIP service subscriber’s Authenticate ID used for authentication. It can be identical to
or different from the SIP User ID.
SIP Authentication Password
Configures the account password required for the device to authenticate with the ITSP (SIP) server
before the account can be registered. After saving, it will appear as hidden for security purpose
Display Name
Configures the subscriber’s name (optional) that will be used for Caller ID display.
Tel URI
Indicates E.164 number in “From” header by adding “User=Phone” parameter or using “Tel:” in SIP
packets, if the device has an assigned PSTN Number.
● Disabled: Will use “SIP User ID” information in the Request-Line and “From” header.
● User=Phone: “User=Phone” parameter will be attached to the Request-Line and “From” header in
the SIP request to indicate the E.164 number. If set to “Enable”.
● Enabled: “Tel:” will be used instead of “sip:” in the SIP request.
Please consult your carrier before changing this parameter. Default is “Disabled”.
Network Settings
DNS Mode
Defines which DNS service will be used to lookup IP address for SIP server’s hostname. There are 4
modes:
● A Record
● SRV
● NATPTR/SRV
● User Configured IP
To locate the server by DNS SRV set this option to “SRV” or “NATPTR/SRV”. Default setting is “A
Record”.
NAT Traversal
Specifies which NAT traversal mechanism will be enabled on the device. It can be selected from the
dropdown list:
● No
● STUN
● Keep-Alive
● UPnP
● Auto
● VPN
If the outbound proxy is configured and used, it can be set to “NAT NO”.
If set to “STUN” and STUN server is configured, the device will periodically send STUN message to
the SUTN server to get the public IP address of its NAT environment and keep the NAT port open.
STUN will not work if the NAT is symmetric type.
If set to “Keep-alive”, the device will send the STUN packets to maintain the connection that is first
established during registration of the device. The “Keep-alive” packets will fool the NAT device into
keeping the connection open and this allows the host server to send SIP requests directly to the
registered phone.
If it needs to use OpenVPN to connect host server, it needs to set it to “VPN”. If the firewall and the

SIP device behind the firewall are both able to use UPNP, it can be set to “UPNP”. The both parties
will negotiate to use which port to allow SIP through. The default setting is “Keep-alive”.
The default settings is "Auto"
Proxy-Require
Adds the Proxy-Required header in the SIP message. It is used to indicate proxy-sensitive features that
must be supported by the proxy. Do not configure this parameter unless this feature is supported on the
SIP server.
Table 12: Accounts – General Settings page
Accounts/SIP Settings
Basic Settings
SIP Registration
Allows the device to send SIP REGISTER messages to the proxy/server. The default setting is
“Yes”.
UNREGISTER on Reboot
If set to "No", the device will not unregister the SIP user's registration information before new
registration. If set to "All", the SIP Contact header will use "*" to clear all SIP user's registration
information. If set to "Instance", the device only needs to clear the current SIP user's info
REGISTER Expiration
Configures the time period (in minutes) in which the device refreshes its registration with the
specified registrar. The default setting is 60. The maximum value is 64800 (about 45 days).
SUBSCRIBE Expiration
Specifies the frequency (in minutes) in which the device refreshes its subscription with the
specified register. The maximum value is 64800 (about 45 days).
Re-Register before Expiration
Specifies the time frequency (in seconds) that the device sends re-registration request before the
Register Expiration. The default setting is 0. The range is from 0 to 64,800.
Registration Retry Wait Time
Configures the time period (in seconds) in which the device will retry the registration process in
the event that is failed. The default setting is 20. The maximum value is 3600 (1 hour).
Add Auth Header on Initial
REGISTER
If enabled, the device will add Authorization header in initial REGISTER request.
Enable OPTIONS Keep-Alive
Enables SIP OPTIONS to track account registration status so the device will send periodic
OPTIONS message to server to track the connection status with the server. The default setting is
“No”.
OPTIONS Keep-Alive Interval
Configures the time interval when the device sends OPTIONS message to SIP server. The default
value is 30 seconds, in order to send an OPTIONS message to the server every 30 seconds.
The default range is 1-64800.
OPTIONS Keep-Alive Max Tries
Configures the maximum times of sending OPTIONS message consistently from the device to
server. Device will keep sending OPTIONS messages until it receives response from SIP server.
The default setting is “3”, which means when the device sends OPTIONS message for 3 times, and
SIP server does not respond this message, the device will send RE-REGISTER message to register
again. The valid range is 3-10.
SUBSCRIBE for Registration
When set to "Yes", a SUBSCRIBE for Registration will be sent out periodically.
Use Privacy Header
Controls whether the Privacy header will present in the SIP INVITE message or not, whether the
header contains the caller info:
● If set to “Yes”, the Privacy Header will always show in INVITE
● If set to “No”, the Privacy Header will not show in INVITE.