Grandstream Networks DUAL FXS PORT HT502 User manual

HT502 USER MANUAL
Grandstream Networks, Inc.
HT502
Dual FXS Port
Analog Telephone Adaptor

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 2 of 49
HT502 USER MANUAL
INDEX
GNU GPL INFORMATION...........................................................................5
CHANGE LOG.............................................................................................6
CHANGES FROM 1.0.7.6 USER MANUAL ..........................................................................................6
CHANGES FROM 1.0.6.8 USER MANUAL ..........................................................................................6
WELCOME ..................................................................................................7
SAFETY COMPLIANCES......................................................................................................................7
WARRANTY...........................................................................................................................................7
CONNECT YOUR HT502 ............................................................................9
EQUIPMENT PACKAGING ...................................................................................................................9
CONNECTING THE HT502...................................................................................................................9
PRODUCT OVERVIEW.............................................................................12
SOFTWARE FEATURES OVERVIEW................................................................................................12
HARDWARE SPECIFICATION............................................................................................................14
BASIC OPERATIONS ...............................................................................15
UNDERSTANDING HT502 VOICE PROMPT.....................................................................................15
PLACING A PHONE CALL ..................................................................................................................16
PHONE OR EXTENSION NUMBERS..........................................................................................16
DIRECT IP CALLS........................................................................................................................17
CALL HOLD.........................................................................................................................................18
CALL WAITING....................................................................................................................................18
CALL TRANSFER................................................................................................................................18
3-WAY CONFERENCING....................................................................................................................19
FAX SUPPORT....................................................................................................................................20
CALL FEATURES .....................................................................................21
CONFIGURATION GUIDE.........................................................................23
CONFIGURING THE HT502 THROUGH VOICE PROMPTS.............................................................23
CONFIGURING THE HT502 VIA WEB BROWSER............................................................................24
ACCESS THE WEB CONFIGURATION MENU...........................................................................24
IMPORTANT SETTINGS.....................................................................................................................25
NAT SETTINGS............................................................................................................................25
DTMF METHODS.........................................................................................................................26

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 3 of 49
PREFERRED VOCODER (CODEC)............................................................................................26
ADVANCED USER CONFIGURATION...............................................................................................30
SAVING THE CONFIGURATION CHANGES......................................................................................43
REBOOTING THE HT502 FROM REMOTE.......................................................................................43
CONFIGURATION THROUGH A CENTRAL SERVER.......................................................................43
SOFTWARE UPGRADE............................................................................45
FIRMWARE UPGRADE THROUGH TFTP/HTTP/HTTPS..................................................................45
INSTRUCTIONS LOCAL FIRMWARE UPGRADE:.............................................................................46
CONFIGURATION FILE DOWNLOAD................................................................................................46
FIRMWARE AND CONFIGURATION FILE PREFIX AND POSTFIX ..................................................47
MANAGING FIRMWARE AND CONFIGURATION FILE DOWNLOAD..............................................47
RESTORE FACTORY DEFAULT SETTING..............................................48
FACTORY RESET...............................................................................................................................48
RESET BUTTON .................................................................................................................................48
IVR COMMAND...................................................................................................................................48

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 4 of 49
TABLE OF FIGURES
HT502 User Manual
FIGURE 1: CONNECTING THE HT502 .....................................................................................................10
FIGURE 2: HT502 CONNECTION DIAGRAM............................................................................................11
FIGURE 3: UPLINK/DOWNLINK BANDWIDTH LIMITATION ...................................................................29
TABLE OF TABLES
HT502 User Manual
TABLE 1: DEFINITIONS OF THE HT502 CONNECTORS .......................................................................10
TABLE 2: DEFINITIONS OF THE HT502 LEDS........................................................................................10
TABLE 3: HT502 TECHNICAL SPECIFICATIONS....................................................................................12
TABLE 4: HT502 HARDWARE SPECIFICATION......................................................................................14
TABLE 5: HT502 IVR MENU DEFINITIONS..............................................................................................15
TABLE 6: HT502 CALL FEATURES ..........................................................................................................21
TABLE 7: BASIC SETTINGS.....................................................................................................................26
TABLE 8: STATUS PAGE...........................................................................................................................29
TABLE 9: ADVANCED SETTINGS ............................................................................................................31
TABLE 10: ACCOUNT SETTINGS ............................................................................................................35
CONFIGURATION GUI INTERFACE EXAMPLES
HT502 User Manual
(http://www.grandstream.com/products/ht_series/ht502/documents/ht502_gui.zip)
1. SCREENSHOT OF ADVANCED USER CONFIGURATION PAGE
2. SCREENSHOT OF BASIC SETTINGS CONFIGURATION PAGE
3. SCREENSHOT OF FXS PORT 1CONFIGURATION LOGIN PAGE
4. SCREENSHOT OF FXS PORT 2CONFIGURATION PAGE
5. SCREENSHOT OF STATUS PAGE
6. SCREENSHOT OF LOGIN PAGE
7. SCREENSHOT OF REBOOT PAGE
8. SCREENSHOT OF REBOOTING PAGE

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 5 of 49
GNU GPL INFORMATION
HT502 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.com/support/faq/gnu_gpl .

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 6 of 49
CHANGE LOG
This section documents significant changes from previous versions of HT502 user manuals. Only major
new features or major document updates are listed here. Minor updates for corrections or editing are not
documented here.
CHANGES FROM 1.0.7.6 USER MANUAL
Added option to enable/disable SIP NOTIFYAuthentication. [Disable SIP NOTIFY Authentication]
Added option [Use Configured IP ] in DNS mode. Added configurable parameter [Primary IP][Backup
IP1][Backup IP2]
Added option to set [Reregister before Expiration]
CHANGES FROM 1.0.6.8 USER MANUAL
Added the option to enable/disable hook flash. [Enable Hook Flash]
Added two CPE SSL configuration [CPE SSL Certificate][CPE SSL Private Key]
Added a configuration parameter to set the [Connection Request Port]
Removed DHCP Domain from Web UI
Removed Enable Ring-transfer from Web UI
Added a configuration parameter to set the [Offhook Auto-Dial Delay]
Changed the SSL Web UI decription to [SIP TLS Certificate][SIP TLS Private Key] and [SIP TLS Private
Key Password]
Added [CPE] version to Software Version on Web UI

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 7 of 49
WELCOME
Thank you for purchasing Grandstream’s HT502, the affordable, feature rich Analog Telephone Adaptor.
Grandstream HandyTone502 is a new addition to the popular HandyTone ATA product family. It features
the rich audio quality, a broad range of voice codecs, and functionality of the HT502, including two (2)
FXS ports each with independent SIP accounts.
This manual will help you learn how to operate and manage your HandyTone502 Analog Telephone
Adaptor and make the best use of its many upgraded features including simple and quick installation, 3-
way conferencing, and direct IP-IP Calling. This HT502 is very easy to manage and configure, and is
specifically designed to be an easy to use and affordable VoIP solution for both the residential user and
the teleworker.
SAFETY COMPLIANCES
The HT502 phone complies with FCC/CE and various safety standards. The HT502 power adaptor is
compliant with UL standard. Only use the universal power adapter provided with the HT502 package.
The manufacturer’s warranty does not cover damages to the phone caused by unsupported power
adaptors.
WARRANTY
If you purchased your HT502 from a reseller, please contact the company where you purchased your
device 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.
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. Please do not use a different power adaptor with the HT502 as it may cause damage to the
products and void the manufacturer warranty.
This document contains links to HT502 GUI Interfaces. Please download these examples from
http://www.grandstream.com/products/ht_series/ht502/documents/ht502_gui.zip for your reference.

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 8 of 49
This document is subject to change without notice. The latest electronic version of this user manual is
available for download at:
http://www.grandstream.com/products/ht_series/ht502/documents/ht502_usermanual_english.pdf
Reproduction or transmittal of the entire or any part, in any form or by any means, electronic or print, for
any purpose is not permitted without the express written permission of Grandstream Networks, Inc.

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 9 of 49
CONNECT YOUR HT502
EQUIPMENT PACKAGING
The HT502 ATA package contains:
One HT502 Main Case
One Universal Power Adaptor
One Ethernet Cable
One HT502 Vertical Stand
CONNECTING THE HT502
The HT502 is designed for easy configuration and easy installation. Configure the HT502 following the
directions in the Configuration section of this manual.
1. Connect a standard touch-tone analog telephone to the PHONE port.
2. Insert a standard RJ11 telephone cable into the Phone1 port and connect the other end of the
telephone cable to the analog telephone.
3. Insert the Ethernet cable into the WAN port of HT502 and connect the other end of the Ethernet
cable to an uplink port (a router or a modem, etc.)
4. Connect a PC to the LAN port of HT502 if it is being used as a router.
5. Insert the power adapter into the HT502 and connect it to a wall outlet.
The HT502 Analog Telephone Adaptor is an all-in-one VoIP integrated device designed to be a total
solution for networks providing VoIP services. The HT502 VoIP features and functions are available using
a regular analog telephone.

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 10 of 49
FIGURE 1: CONNECTING THE HT502
The HT502 has two FXS port. Both FXS ports can have a separate SIP account. This is a key feature of
HT502 as it supports simultaneous calls on both FXS ports.
TABLE 1: DEFINITIONS OF THE HT502 CONNECTORS
Power Cable
Power adapter connection
WAN Port (RJ-45)
Connect to the internal LAN network or router.
LAN Port (RJ-45)
Connect the LAN port with an Ethernet cable to your PC.
RESET
Factory Reset button. Press for 7 seconds to reset factory default settings.
PHONE1 (RJ-11)
FXS port to be connected to analog phones / fax machines.
PHONE2 (RJ-11)
FXS port to be connected to analog phones / fax machines.
There are five (5) LED buttons that help you manage the status of your HandyTone.
TABLE 2: DEFINITIONS OF THE HT502 LEDS
LEDs
POWER LED
Indicates Power. Remains ON when power is connected
WAN LED
Indicates LAN (or WAN) port activity
LAN LED
Indicates PC (or LAN) port activity
PHONE1 / PHONE2 LED
Indicate status of the respective FXS Ports-PHONE1 /
PHONE2 on the back panel
Busy –ON (Solid Green)
HT-502
Back View
RJ-45 Ports
10/100 Mbps
Reset
RJ-11 FXS Ports
(Phone)
Power
Supply
(12V)
HT-502
Front View
Display LEDs
(green)

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 11 of 49
Internet
ADSL/Cable
Modem Ethernet
WAN
LAN
FXS
Fax
Cordless
Phone
Analog Phone
FXS
Fax
Cordless
Phone
Analog Phone
Available –OFF
Slow blinking FXS LEDs indicates voicemail for that port.
NOTE: All LEDs display green when ON. Slow blinking of WAN and LAN LED together indicate the
product in firmware upgrading or provision state.
FIGURE 2: HT502 CONNECTION DIAGRAM

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 12 of 49
PRODUCT OVERVIEW
The HT502 is a full feature voice and fax-over IP device that offers a high-level of integration including
dual 10M/100Mbps network ports with integrated router, NAT, DHCP server, dual port FXS telephone
gateway, market-leading sound quality, rich functionalities, and a compact and lightweight design. The
VoIP network signaling protocol supported is SIP. The HT502 fully compatible with SIP industry standard
and can interoperate with many other SIP compliant devices and software on the market. Moreover, it
supports comprehensive voice codecs including G.711 (a/µ-law), G.723.1, G.726 (16/24/32/40 bit rates),
AAL2 (all G.726), G.729A/B/E and iLBC.
SOFTWARE FEATURES OVERVIEW
2 FXS ports
Two RJ-45 ports (switched or routed)
2 SIP accounts & profiles
Supports Voice Codecs:
G711(a/µ, Annex I & II), G723.1A, G726 (ADPCM with 16/24/32/40 bit rates), G729 A/B/E, iLBC
T.38 Fax
Comprehensive Dial Plan support for Outgoing calls.
G.168 Echo Cancellation
Voice Activation Detection (VAD), Comfort Noise Generation (CNG), and Packet Loss
Concealment (PLC)
Supports PSTN/PBX analog telephone sets or analog trunks
TABLE 3: HT502 TECHNICAL SPECIFICATIONS
Telephone Interfaces
2 FXS ports, 2 SIP accounts
Network Interface
1 RJ45 for LAN, 10/100 Base-TX, Full Duplex
1 RJ45 for WAN,10/100Base-TX, Full Duplex
LED Indicators
Power, WAN, LAN, PHONE1 and PHONE2
Reset Button
Factory Reset button
Voice over Packet
Capabilities
Voice Activity Detection (VAD) with CNG (comfort noise generation) and PLC (packet
loss concealment), Dynamic Jitter Buffer, Modem detection & auto-switch to G.711,
Packetized Voice Protocol Unit (supports RTP/RTCP and AAL2 protocol), G.168
compliant Echo Cancellation, LEC (line echo cancellation) with NLP, Asymmetric RTP
stream

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 13 of 49
Voice Compression
G.711 + Annex I (PLC), Annex II (VAD/CNG format) encoder and decoder, G.723.1A,
G.726(ADPCM), G.729A/B/E, iLBC, G.726 provides proprietary VAD, CNG, and signal
power estimation, Voice Play Out unit (reordering, fixed and adaptive jitter buffer, clock
synchronization), AGC (automatic gain control), Status output, Decoder controlling via
voice packet header
DHCP Server/Client
Yes, NAT Router or Switched Mode
Telnet Server
Yes
Fax over IP
T.38 compliant Group 3 Fax Relay up to 14.4kpbs and auto-switch to G.711 for Fax
Pass-through, Fax Datapump V.17, V.19, V.27ter, V.29 for T.38 fax relay
QoS
Diffserve, TOS, 802.1 P/Q VLAN tagging
IP Transport
RTP/RTCP
DTMF Method
Flexible DTMF transmission method, user interface of In-audio, RFC2833, and/or SIP
Info
IP Signaling
SIP (RFC 3261)
Provisioning
TFTP, HTTP, HTTPS
Control
TLS/SIPS , SIP over TCP/TLS
Device Management
Web interface or via secure encrypted AES or non-encrypted central configuration file
for mass deployment, Auto/manual provisioning system or via built-in IVR.
NAT-friendly remote software upgrade (via TFTP/HTTP/HTTPS) for deployed devices
including behind firewall/NAT. Syslog support
Dial Plan
Yes
UPnP
Yes
Universal Switching
Power Adaptor
Input: 100–240 VAC/50-60 Hz 0.3A Max
Output: 12VDC, 0.5A, UL certified
Environmental
Operational: 32o–104oF or 0o–40oC
Storage: 10o–130oF / Humidity: 10–90% Non-condensing
Dimensions
(H x W x D)
115mm (L) x 75mm (W) x 27mm (H)
Short Haul Loop
3RENs, Up to 150feet on 24 AWG wire
Call Handling Features
Caller ID display or block, Call waiting caller ID, Call waiting/flash, Call transfer, hold,
forward, mute, 3-way conferencing, message waiting, Do-Not-Disturb (DND), call-return
service
Caller ID
Bellcore Type 1 & 2, ETSI, BT, NTT, and DTMF-based CID
Polarity Reversal / Wink
Yes
EMC
EN55022/EN55024 and FCC part15 Class B
Safety
UL

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 14 of 49
HARDWARE SPECIFICATION
The table below lists the hardware specification of HT502.
TABLE 4: HT502 HARDWARE SPECIFICATION
LAN Interface
2 x RJ45 10/100Mbps (integrated router)
LED
5 LEDs (GREEN)
Universal Switching
Power Adaptor
Input: 100-240VAC, 50/60Hz, 0.5A Max
Output: 12V DC, 0.5A
UL certified
Dimension
115mm (L) x 75mm (W) x 27mm (H)
Weight
94 g (0.21lbs)
Temperature
32~104°F / 0~40°C
Humidity
10% - 90% (non-condensing)
Compliance

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 15 of 49
BASIC OPERATIONS
UNDERSTANDING HT502 VOICE PROMPT
HT502 has a built-in voice prompt menu for simple device configuration. The IVR menu and the LED
button work with any of the FXS port. Pick up the handset and dial “***”to use the IVR menu.
TABLE 5: HT502 IVR MENU DEFINITIONS
Menu
Voice Prompt
Options
Main Menu
“Enter a Menu Option”
Press “*” for the next menu option
Press “#” to return to the main menu
Enter 01-05, 07,10, 12-17,47 or 99 menu options
01
“DHCP Mode”,
“Static IP Mode”
Press “9” to toggle the selection
If using “Static IP Mode”, configure the IP address information using
menus 02 to 05.
If using “Dynamic IP Mode”, all IP address information comes from
the DHCP server automatically after reboot.
02
“IP Address “ + IP address
The current WAN IP address is announced
If using “Static IP Mode”, enter 12 digit new IP address. You need to
reset the HT to take affect the new IP address.
03
“Subnet “ + IP address
Same as menu 02
04
“Gateway “ + IP address
Same as menu 02
05
“DNS Server “ + IP address
Same as menu 02
07
Preferred Vocoder
Press “9” to move to the next selection in the list:
PCM U / PCM A
iLBC
G-726
G-723
G-729
10
“MAC Address”
Announces the Mac address of the unit.
12
WAN Port Web Access
Press “9” to toggle between enable / disable
13
Firmware Server IP
Address
Announces current Firmware Server IP address. Enter 12 digit new
IP address.
14
Configuration Server IP
Address
Announces current Config Server Path IP address. Enter 12 digit
new IP address.
15
Upgrade Protocol
Upgrade protocol for firmware and configuration update. Press “9” to

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 16 of 49
toggle between TFTP / HTTP / HTTPS
16
Firmware Version
Firmware version information.
17
Firmware Upgrade
Firmware upgrade mode. Press “9” to toggle among the following
three options:
- always check
- check when pre/suffix changes
- never upgrade
47
“Direct IP Calling”
Enter the target IP address to make a direct IP call, after dial tone.
(See “Make a Direct IP Call”.)
70
Phone calls between FXS 1
and FXS 2 port
User can make internal calls between two FXS ports on the same
HT502 even without being registered to SIP server. By dialing *** and
70 user can reach the other FXS port
86
Voice Mail
Number of Voice Mails
99
“RESET”
Press “9” to reboot the device
Enter MAC address to restore factory default setting
(See Restore Factory Default Setting section)
“Invalid Entry”
Automatically returns to main menu
“Device not registered”
This prompt will be played immediately after off hook If the device is
not register and the option “Outgoing Call without Registration” is in
NO
Five Success Tips when using the Voice Prompt
1. “*” shifts down to the next menu option
2. “#” returns to the main menu
3. “9” functions as the ENTER key in many cases to confirm an option
4. All entered digit sequences have known lengths - 2 digits for menu option and 12 digits for IP
address. For IP address, add 0 before the digits if the digits are less than 3 (i.e. - 192.168.0.26
should be key in like 192168000026. No decimal is needed).
5. Key entry can not be deleted but the phone may prompt error once it is detected
PLACING A PHONE CALL
PHONE OR EXTENSION NUMBERS
1. Dial the number directly and wait for 4 seconds (Default “No Key Entry Timeout”); or

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 17 of 49
2. Dial the number directly and press # (Use # as dial key” must be configured in web configuration).
Examples:
1. Dial an extension directly on the same proxy, (e.g. 1008), and then press the # or wait for 4 seconds.
2. Dial an outside number (e.g. [phone]), first enter the prefix number (usually 1+ or international
code) followed by the phone number. Press # or wait for 4 seconds. Check with your VoIP service
provider for further details on prefix numbers.
DIRECT IP CALLS
Direct IP calling allows two parties, that is, a FXS Port with an analog phone and another VoIP Device, to
talk to each other in an ad hoc fashion without a SIP proxy.
Elements necessary to completing a Direct IP Call:
1. Both HT502 and other VoIP Device, have public IP addresses, or
2. Both HT502 and other VoIP Device are on the same LAN using private IP addresses, or
3. Both HT502 and other VoIP Device can be connected through a router using public or private IP
addresses (with necessary port forwarding or DMZ).
HT502 supports two ways to make Direct IP Calling:
Using IVR
1. Pick up the analog phone then access the voice menu prompt by dial “***”
2. Dial “47” to access the direct IP call menu
3. Enter the IP address after the dial tone and voice prompt “Direct IP Calling”
Using Star Code
1. Pick up the analog phone then dial “*47”
2. Enter the target IP address.
Note: NO dial tone will be played between step 1 and 2.
Destination ports can be specified using “*” (encoding for “:”) followed by the port number.

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 18 of 49
Examples of Direct IP Calls:
a) If the target IP address is 192.168.0.160, the dialing convention is
*47 or Voice Prompt with option 47, then 192*168*0*160.
followed by pressing the “#” key if it is configured as a send key or wait 4 seconds. In this case,
the default destination port 5060 is used if no port is specified.
b) If the target IP address/port is 192.168.1.20:5062, then the dialing convention would be:
*47 or Voice Prompt with option 47, then 192*168*0*160*5062 followed by pressing the “#” key
if it is configured as a send key or wait for 4 seconds.
NOTE: When completing direct IP call, the “Use Random Port” should set to “NO”. You cannot make
direct IP calls between FXS1 to FXS2 since they are using same IP.
CALL HOLD
Place a call on hold by pressing the “flash” button on the analog phone (if the phone has that button).
Press the “flash” button again to release the previously held Caller and resume conversation. If no “flash”
button is available, use “hook flash” (toggle on-off hook quickly). You may drop a call using hook flash.
CALL WAITING
Call waiting tone (3 short beeps) indicates an incoming call, if the call waiting feature is enabled. Toggle
between incoming call and current call by pressing the “flash” button. First call is placed on hold. Press
the “flash” button to toggle between two active calls.
CALL TRANSFER
Blind Transfer
Assume that call CallerA and B are in conversation.A wants to Blind Transfer B to C:
3. Caller A presses FLASH on the analog phone to hear the dial tone.
4. Caller A dials *87 then dials caller C’s number, and then # (or wait for 4 seconds)
5. Caller A will hear the confirm tone. Then,A can hang up.
NOTE: “Enable Call Feature” must be set to “Yes” in web configuration page.

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 19 of 49
Caller A can place a call on hold and wait for one of three situations:
1. A quick confirmation tone (similar to call waiting tone) followed by a dial-tone. This indicates the
transfer is successful (transferee has received a 200 OK from transfer target). At this point, Caller
A can either hang up or make another call.
2. A quick busy tone followed by a restored call (on supported platforms only). This means the
transferee has received a 4xx response for the INVITE and we will try to recover the call. The
busy tone is just to indicate to the transferor that the transfer has failed.
3. Continuous busy tone. The phone has timed out.
Note: continuous busy tone does not indicate the transfer has been successful, nor does it indicate
the transfer has failed. It often means there was a failure to receive second NOTIFY –check
firmware for most recent release.
Attended Transfer
Assume that Caller A and B are in conversation. Caller A wants to Attend Transfer B to C:
1. Caller A presses FLASH on the analog phone for dial tone.
2. Caller A then dials Caller C’s number followed by # (or wait for 4 seconds).
3. If Caller C answers the call, Caller A and Caller C are in conversation. Then A can hang up to
complete transfer.
4. If Caller C does not answer the call, Caller A can press “flash” to resume call with Caller B.
NOTE: When Attended Transfer fails and A hangs up, the HT502 will ring back user A to remind A that B
is still on the call. A can pick up the phone to resume conversation with B.
3-WAY CONFERENCING
The HT502 supports Bellcore style 3-way Conference.
Instructions for 3-way conference:
Assume that call party A and B are in conversation. Caller A(HT502) wants to bring third Caller C into
conference:
1. A presses FLASH (on the analog phone, or Hook Flash for old model phones) to get a dial tone.
2. A dials C’s number then # (or wait for 4 seconds).

FIRMWARE VERSION 1.0.8.4 HT502 USER MANUAL Page 20 of 49
3. If C answers the call, thenA presses FLASH to bring B, C in the conference.
4. If C does not answer the call,A can press FLASH back to talk to B.
5. If A presses FLASH during conference, C will be dropped out.
6. If A hangs up, the conference will be terminated for all three parties when configuration “Transfer
on Conference Hangup” is set to “No”. If the configuration is set to “Yes”, A will transfer B to C so
that B and C can continue the conversation.
FAX SUPPORT
HT502 supports FAX in two modes: 1) T.38 (Fax over IP) and 2) fax pass through. T.38 is the preferred
method because it is more reliable and works well in most network conditions. If the service provider
supports T.38, please use this method by selecting Fax mode to be T.38 (default). If the service provider
does not support T.38, pass-through mode can be used.