How to Use Your TSN Phone Desk Phone — Basic Features and Everyday Calling

Applies to: Compatible Yealink and Grandstream Desk Phones
Difficulty: Beginner
Estimated Time: 5–10 minutes

Overview

TSN Phone supports compatible business desk phones that allow you to make and receive calls using your organization’s telephone system. A desk phone provides familiar calling features such as answering calls, transferring customers, putting calls on hold, accessing voicemail, and contacting coworkers using internal extensions. Depending on your phone model, you may also have programmable buttons that allow you to quickly call coworkers or see whether their extensions are busy. This guide explains the everyday calling features available on compatible TSN Phone desk phones.

Before You Begin:

  • Make sure your desk phone is connected to power and the network.
  • Confirm that the phone has been set up by True Synergy Networks.
  • Know your assigned extension number.
  • Have your voicemail PIN available if required.
  • Familiarize yourself with the buttons on your phone.
  • Make sure your handset or headset is connected.

Important: Desk phones are configured and managed by True Synergy Networks. Do not factory reset the device, modify SIP accounts, or change network settings without authorization.

Note: Button locations and menu names vary between Yealink and Grandstream phone models.

Understanding Your Desk Phone

Most TSN Phone desk phones include several common components.

Handset

The handset allows you to speak privately during a telephone conversation. Lift the handset to answer or place a call, and return it to the cradle to end the conversation.

Speakerphone

The speakerphone allows you to make and receive calls without holding the handset. Most phones have a dedicated speakerphone button.

Note: Speakerphone may not be appropriate for confidential conversations in shared offices.

Keypad

The keypad is used to enter telephone numbers, internal extensions, voicemail PINs, and supported feature codes.

Display Screen

The screen may show:

  • Your assigned extension.
  • Date and time.
  • Incoming caller information.
  • Call duration.
  • Missed calls.
  • Contact directory entries.
  • Available soft keys.

Soft Keys

Soft keys are buttons located near or beneath the display. Their functions change depending on what is happening on the phone.
Common soft key labels include:

  • Call
  • Answer
  • Transfer
  • Hold
  • End Call
  • Directory
  • History
  • More

Note: Some phones use on-screen controls rather than dedicated physical buttons.

Line Keys

Line keys allow you to access assigned lines or other configured functions. Depending on your phone, these buttons may be used for:

  • Your extension.
  • Additional call appearances.
  • Coworker extensions.
  • Speed dialing.
  • Call parking.
  • Other approved features.

BLF Buttons

BLF stands for Busy Lamp Field. A BLF button can display the status of another extension and may allow you to call that coworker with one button press. BLF functionality is explained later in this guide.

How to Answer an Incoming Call

When someone calls your extension, your desk phone will normally ring and display caller information.

Option 1: Answer Using the Handset

  1. Wait for the incoming call.
  2. Lift the handset.
  3. Begin speaking.

To end the call, return the handset to the cradle.

Option 2: Answer Using Speakerphone

  1. Wait for the incoming call.
  2. Press the Speakerphone button or Answer soft key.
  3. Begin speaking.

To end the call, press the speakerphone button again or select End Call.

Important: Use a handset or headset when discussing sensitive information.

Option 3: Answer Using a Headset

If a compatible headset is connected:

  1. Wait for the incoming call.
  2. Press the Headset button or the appropriate answer control.
  3. Begin speaking.

To end the call, use the phone’s End Call control or a supported headset call button.

Note: Headset answer and hang-up functions depend on the headset model and integration.

How to Make an Internal Call

Internal calls connect you to another extension within your organization’s TSN Phone system.

Step 1: Obtain the Extension

Identify the coworker’s extension number.

For example: Extension 102

Step 2: Dial the Extension

  1. Lift the handset or activate speakerphone.
  2. Enter the extension number.
  3. Press Send, Call, or the available dialing button if necessary.
  4. Wait for the coworker to answer.

Note: Some phones automatically place the call after a short pause. Internal extensions may use different number lengths depending on your organization.

How to Make an External Call

External calls connect you to telephone numbers outside your organization’s phone system.

Step 1: Enter the Number

  1. Lift the handset or activate speakerphone.
  2. Dial the telephone number.
  3. Review the displayed digits.

Step 2: Place the Call

  1. Press Send, Call, or the appropriate dialing button.
  2. Wait for the call to connect.
  3. Begin speaking.

Example:

To call a standard U.S. telephone number, enter the complete 10-digit number unless your organization has instructed you to use another format.

Important: Some organizations support seven-digit local dialing, while others require a full area code. Follow your organization’s assigned dialing rules.

Note: Your caller ID may display the company telephone number or another authorized number, depending on your extension settings.

How to Put a Call on Hold

Call Hold allows you to temporarily pause a conversation without disconnecting the caller.

Step 1: Place the Caller on Hold

While connected to a call:

  1. Press the Hold button or soft key.
  2. Confirm that the display indicates the call is on hold.
  3. The caller may hear your organization’s configured hold music.

Step 2: Resume the Call

  1. Locate the held call on the display.
  2. Press Resume, Unhold, or the corresponding line control.
  3. Confirm that the caller is connected again.

Important: Hold is different from Mute. Hold temporarily suspends the active conversation, while Mute only disables your microphone.

Tip: Ask the caller for permission before placing them on hold.

How to Mute Your Microphone

Mute prevents the other person from hearing you while allowing you to continue hearing them.

Step 1: Enable Mute

  1. While connected to a call, press Mute.
  2. Confirm that the mute indicator appears on the display or button.

Step 2: Disable Mute

  1. Press Mute again.
  2. Confirm that the indicator turns off.
  3. Continue speaking.

Important: Muting does not place the caller on hold or disconnect the call.

Understanding Call Transfers

Your desk phone may support two common transfer methods.

Blind Transfer

A blind transfer sends the caller to another extension without speaking to the recipient first.

Example: A customer calls Reception and requests Billing. Reception transfers the caller directly to Billing.

Attended Transfer

An attended transfer allows you to speak with the recipient before connecting the original caller.

Example: A customer calls Reception asking for a manager. The receptionist contacts the manager, explains the situation, and then completes the transfer.

Recommendation: Use an attended transfer when the receiving employee needs additional information before speaking with the caller.

How to Perform a Blind Transfer

Step 1: Answer the Call

  1. Answer the incoming call.
  2. Determine which employee or department should receive it.
  3. Tell the caller you are transferring them.

Step 2: Start the Transfer

  1. Press Transfer or Trans.
  2. Select Blind Transfer if the phone presents transfer options.
  3. Enter the destination extension.

On some models, simply entering the destination and completing the transfer without consulting the recipient performs a blind transfer.

Step 3: Complete the Transfer

  1. Review the destination.
  2. Press Transfer, B Transfer, or the displayed confirmation control.
  3. Confirm that the original call is no longer active on your phone.

Important: The exact transfer sequence varies by phone model and firmware. A blind transfer does not guarantee that the receiving employee will answer.

How to Perform an Attended Transfer

Step 1: Answer the Call

  1. Answer the customer’s call.
  2. Determine which employee should receive the transfer.
  3. Inform the caller that you will check whether the person is available.

Step 2: Contact the Recipient

  1. Press Transfer or the available transfer control.
  2. Select Attended Transfer, if displayed.
  3. Enter the destination extension.
  4. Initiate the consultation call.
  5. Wait for the recipient to answer.

The original caller is typically placed on hold during this process.

Step 3: Speak With the Employee

  1. Explain who is calling.
  2. Provide any relevant details.
  3. Confirm that the employee is ready to accept the call.

Step 4: Complete the Transfer

  1. Press Transfer again or select the completion control.
  2. Confirm that the original caller has been connected to the recipient.
  3. Verify that your call has ended.

Important: Do not simply hang up unless your phone’s documented transfer procedure specifically instructs you to do so. If the recipient does not answer, use the available Cancel or Resume control to return to the original caller.

How to Check Your Voicemail

Your desk phone may provide a dedicated voicemail button.

Step 1: Open Voicemail

  1. Press the Message or Voicemail button, if configured.
  2. Alternatively, dial the voicemail access code provided by True Synergy Networks.

A common PBXware default is: *123

Important: The voicemail access code may be customized for your organization.

Step 2: Enter Your PIN

  1. Listen to the voicemail instructions.
  2. Enter your assigned voicemail PIN if prompted.
  3. Follow the available spoken menu options.

Step 3: Listen to Messages

  1. Select the option to listen to new messages.
  2. Listen to the recording.
  3. Follow the spoken prompts to replay, save, or delete the message.
  4. Hang up when finished.

Note: Some organizations automatically email voicemail recordings and remove them from the phone system. In these configurations, your desk phone may not show messages that have already been delivered to your email.

How to View Missed Calls and Call History

Most compatible desk phones provide a call history menu.

Step 1: Open History

  1. Locate History, Call History, or the corresponding button.
  2. Open the call list.

Step 2: Select a Call Type

Depending on your phone model, you may see:

  • All Calls.
  • Missed Calls.
  • Received Calls.
  • Dialed Calls.

Step 3: Review the Call

  1. Select the call entry.
  2. Review the telephone number.
  3. Check the date and time, if available.

Step 4: Return the Call

  1. Select the intended call entry.
  2. Press Dial, Send, or the available call control.
  3. Wait for the call to connect.

Important: Verify unfamiliar telephone numbers before returning calls. Caller ID information can be spoofed.

How to Use the Company Directory

Some TSN Phone desk phones provide a company directory containing coworkers and extensions.

Step 1: Open Directory

  1. Locate Directory or Contacts.
  2. Open the available directory.

Step 2: Find a Coworker

  1. Select the appropriate directory or contact source.
  2. Search for the coworker’s name.
  3. Review the matching results.
  4. Select the correct contact.

Step 3: Place the Call

  1. Highlight the contact.
  2. Press Dial or Call.
  3. Wait for the call to connect.

Note: Company directory features depend on your phone’s provisioning and organization configuration. If a coworker is missing or their extension is incorrect, contact True Synergy Networks.

Understanding BLF Buttons

BLF stands for Busy Lamp Field. BLF buttons allow you to monitor the calling status of selected coworkers or extensions.

Depending on your phone model and configuration, a BLF button may show:

  • The extension is available.
  • The extension is currently ringing.
  • The extension is on a call.
  • The monitored extension is unavailable or cannot be monitored.

Important: BLF indicator colors and behaviors are not identical across all Yealink and Grandstream models. Always follow your organization’s phone configuration.

How to Call a Coworker Using BLF

If your phone has a programmed BLF button:

  1. Locate the button labeled with the coworker’s name or extension.
  2. Check the status indicator, if available.
  3. Press the button.
  4. Wait for the call to connect.

Tip: BLF buttons are especially helpful for receptionists and employees who regularly call the same coworkers.

How to Transfer a Call Using a BLF Button

Some configured desk phones allow transfers directly to a monitored extension.

Step 1: Answer the Caller

  1. Answer the incoming call.
  2. Determine the appropriate coworker.
  3. Inform the caller that you are transferring them.

Step 2: Use the BLF Button

  1. Press Transfer if required by your phone’s configuration.
  2. Press the coworker’s BLF button.
  3. Complete the transfer using the displayed instructions.

Important: Pressing a BLF button during an active call may initiate a blind transfer, an attended transfer, or another configured action. Verify the behavior of your particular phone before using BLF transfers with customers.

How to Use an Expansion Module

Some Yealink desk phones support an additional expansion module that provides more programmable buttons. Expansion modules are useful for offices with many employees because they allow you to view additional BLF contacts without switching between pages on the main phone.

Step 1: Locate the Expansion Module

If your desk phone has an expansion module:

  1. Locate the additional screen attached to your desk phone.
  2. Review the displayed coworker names and extensions.
  3. Look for the corresponding status indicators.

Step 2: Call a Coworker

  1. Locate the desired employee.
  2. Press their assigned button.
  3. Wait for the call to connect.

Step 3: Change Pages

If your expansion module supports multiple pages:

  1. Locate the available page controls.
  2. Select the desired page.
  3. Review the additional programmed contacts.

Note: The number of visible buttons and available pages depends on the specific expansion module model.

Important: Expansion module buttons are provisioned by True Synergy Networks. Contact TSN if you need buttons added, removed, or rearranged.

How to Use Do Not Disturb

Some desk phones provide a dedicated Do Not Disturb feature.

Step 1: Enable DND

  1. Locate DND on your desk phone.
  2. Press the button or open the available menu.
  3. Confirm that DND is enabled.

Step 2: Disable DND

  1. Press DND again or reopen the menu.
  2. Disable the feature.
  3. Confirm that the phone returns to normal operation.

Important: Phone-level DND may behave differently from the Do Not Disturb status in your TSN Phone desktop or mobile application. It may not affect every device or departmental ring group associated with your extension.

How to Use Call Park

Call Park places an active call into a shared parking location so another authorized employee can retrieve it.

Step 1: Park the Call

  1. Answer the call.
  2. Inform the caller that you are placing them on a brief hold.
  3. Use the phone’s configured Park button or approved parking sequence.
  4. Listen for or review the assigned parking location.

Step 2: Notify the Coworker

Tell the intended employee the parking location.

For example:

“You have a call parked on 701.”

Step 3: Retrieve the Call

The receiving employee:

  1. Picks up their desk phone.
  2. Dials the assigned parking location.
  3. Waits for the caller to connect.

Note: Your organization may use different parking numbers or methods.

If Call Park is not configured on your phone, contact True Synergy Networks.

How to Adjust Your Ring Volume

Step 1: Locate the Volume Keys

Find the volume adjustment buttons on your desk phone.

They are typically marked with + and − or speaker symbols.

Step 2: Adjust the Ring Volume

  1. Make sure the phone is idle.
  2. Press the volume-up or volume-down button.
  3. Listen for the available ring volume adjustment.
  4. Stop when the volume is comfortable.

Note: Some phones use separate volume settings for the handset, speakerphone, headset, and ringtone.

How to Adjust Call Volume

Handset Volume

  1. Answer or place a call using the handset.
  2. Press the volume buttons.
  3. Adjust the volume while listening.

Speakerphone Volume

  1. Activate speakerphone during a call.
  2. Use the volume buttons.
  3. Adjust the sound as necessary.

Headset Volume

  1. Connect your headset.
  2. Place or answer a call.
  3. Use the phone’s volume controls.
  4. Adjust the headset’s own volume if applicable.

Tip: If the caller sounds distorted, reduce the volume slightly.

How to Switch Between Handset and Speakerphone

During a call, you may be able to change audio modes without disconnecting.

Switch to Speakerphone

  1. While using the handset, press Speakerphone.
  2. Confirm that audio plays through the phone’s speakers.
  3. Return the handset to its cradle if supported.

Switch to Handset

  1. While using speakerphone, lift the handset.
  2. Confirm that the audio moves to the handset.
  3. Continue speaking privately.

Note: Exact behavior varies by desk phone model.

Troubleshooting

My Desk Phone Is Not Ringing

If incoming calls do not ring:

  1. Confirm that the phone has power.
  2. Check your network connection.
  3. Verify that the ring volume is turned up.
  4. Confirm that Do Not Disturb is disabled.
  5. Check whether your extension is receiving calls through another device.
  6. Ask a coworker to place a test call.

If the issue continues, contact True Synergy Networks.

My Phone Says No Service or Registration Failed

If your phone shows a registration error:

  1. Confirm that the network cable is connected.
  2. Check whether the phone has an active network connection.
  3. Verify that your internet service is working.
  4. Avoid changing SIP account settings.
  5. Contact True Synergy Networks.

Important: Registration credentials and SIP configuration are managed by TSN.

I Cannot Make Outgoing Calls

If outbound calling fails:

  1. Check whether the phone is connected.
  2. Confirm that you entered the correct number.
  3. Try calling an internal extension.
  4. Verify that you are using the approved dialing format.
  5. Record any error message.

If the problem continues, contact True Synergy Networks.

I Cannot Hear the Caller

If you cannot hear the person on the other end:

  1. Increase the call volume.
  2. Confirm that the handset is connected.
  3. Test speakerphone if appropriate.
  4. Check your headset connection.
  5. Try another call.

If the issue continues, contact True Synergy Networks.

The Caller Cannot Hear Me

If your microphone is not working:

  1. Check whether Mute is enabled.
  2. Verify that your handset is connected correctly.
  3. Try another audio mode.
  4. Test your headset if one is connected.
  5. Contact True Synergy Networks if the issue continues.

My BLF Buttons Are Not Working

If BLF buttons are missing or show unexpected statuses:

  1. Confirm that the phone is connected.
  2. Check whether the programmed employee is available.
  3. Review whether the button is displaying an error.
  4. Avoid changing programmable key settings.
  5. Contact True Synergy Networks.

Note: BLF monitoring depends on phone configuration and the availability of the monitored extension.

My Expansion Module Is Not Showing Contacts

If the expansion module is blank or missing programmed keys:

  1. Confirm that it is properly connected to the desk phone.
  2. Check whether the desk phone is powered on.
  3. Review the expansion module’s available pages.
  4. Do not disconnect or reconfigure managed equipment unnecessarily.
  5. Contact True Synergy Networks if the issue continues.

I Cannot Transfer Calls

If transfers fail:

  1. Confirm that the original caller is still connected.
  2. Verify the destination extension.
  3. Check that you are using the correct transfer method.
  4. Review the displayed error message.
  5. Contact True Synergy Networks if the issue continues.

My Voicemail Button Is Not Working

If the Message button does not open voicemail:

  1. Confirm that the phone is connected.
  2. Try the approved voicemail access code.
  3. Verify that you are using the correct voicemail PIN.
  4. Contact True Synergy Networks if voicemail remains unavailable.

Important: Do not repeatedly guess your voicemail PIN.

My Phone Displays the Wrong Time

If your desk phone shows an incorrect date or time:

  1. Confirm that the network connection is working.
  2. Check whether other office phones display the same issue.
  3. Contact True Synergy Networks.

Important: Time zone and network time settings are managed through your organization’s phone provisioning.

My Phone Keeps Restarting

If the phone repeatedly reboots:

  1. Check that the power connection is secure.
  2. If the phone uses Power over Ethernet, confirm that its network cable is connected.
  3. Avoid disconnecting equipment during firmware updates.
  4. Record any on-screen error messages.
  5. Contact True Synergy Networks.

Important: Do not factory reset a managed desk phone. A reset may remove its provisioning configuration.

Additional Information

  • TSN Phone supports compatible Yealink and Grandstream business desk phones.
  • Desk phones allow users to make and receive internal and external calls.
  • Hold and Mute are separate calling features.
  • Blind and attended transfers may be available.
  • Voicemail can be accessed through a Message button or an approved access code.
  • Supported desk phones provide call history and contact directory features.
  • BLF buttons can display coworker calling activity.
  • Expansion modules can provide additional programmable keys.
  • Call Park and Call Pickup may be available for authorized users.
  • Ring volume, call volume, and audio modes can generally be adjusted from the phone.
  • True Synergy Networks manages device provisioning, firmware, SIP registration, programmable buttons, and advanced configuration.

Security Reminder: Only use desk phones assigned or approved by your organization. Do not factory reset managed equipment, share voicemail PINs, or modify SIP credentials and network settings. Verify caller identities before discussing confidential information, and avoid using speakerphone for sensitive conversations in shared spaces. If your phone displays unexpected configuration changes, unfamiliar account information, or suspicious calling activity, contact True Synergy Networks immediately.