TelephonesConference Phone
Snom C620 Telephone Manual
Setup, everyday use, maintenance and troubleshooting for the VoIP conference phone, with verified specifications.
- TypeConference Phone
- LineVoIP (IP network)
- Standby power2.1 W
- Est. yearly cost$3.13
About the Snom C620
The Snom C620 is a VoIP conference phone certified under the ENERGY STAR program for telephony.
It connects to your network as a Voice over IP (VoIP) endpoint rather than to an analog phone line. It has one Gigabit Ethernet port. It can be powered over the network cable as a PoE Class 2 device.
Measured standby power is 2.1 W — about 18.4 kWh or $3.13 a year if it stays plugged in around the clock, as phones normally do.
Specifications
| Brand | Snom |
|---|---|
| Model number | C620 |
| Phone type | Conference Phone |
| Line technology | VoIP |
| Configuration | Conference |
| Power over Ethernet class | 2 |
| External power adapter | Included |
| Gigabit Ethernet ports | 1 |
| Standby (idle) power | 2.10 W |
| Off-mode power | 0.00 W |
Safety information
- Use only the power adapter supplied with the phone or exact replacements from the manufacturer.
- Do not use the phone near water — for example near a bathtub, sink or swimming pool — and never handle it with wet hands.
- Avoid using any phone connected to outdoor wiring during a thunderstorm.
- Do not use the phone to report a gas leak while you are near the leak. Leave the area first.
- A VoIP phone works only when its network, power source (PoE switch or adapter) and phone service are up. Keep an alternative way to call 911 during outages.
Setup
- Connect to the network
Connect the phone's LAN port to a network switch port with an Ethernet cable. If the switch provides PoE, the phone powers up from the cable. As a Class 2 device it can draw up to about 6.49 W, so budget at least that much per port on the switch. Where PoE is not available, use the manufacturer's AC adapter instead.
- Provision the phone
Most business VoIP phones are configured automatically from the phone system or by your administrator. For manual setup, enter the SIP account, server and credentials from your service provider in the phone's web interface.
Using your phone
Calls and audio
- Adjust the earpiece or speaker volume during a call with the volume keys; the setting is usually remembered for the next call.
- Keep the conference phone at the center of the table and at least a few feet from walls, laptops and projector fans to improve pickup and reduce echo.
- Call quality on VoIP depends on the network. If voices break up, ask your administrator to prioritize voice traffic (QoS) or use a wired connection.
Power use
Phones stay powered all the time, so standby power is what matters. This model draws 2.1 W when idle. On PoE, the switch supplies this power, and switch conversion losses add slightly to the total.
Care and maintenance
| When | What to do |
|---|---|
| Weekly | Wipe the handset, keypad and display with a soft cloth lightly dampened with water or a mild disinfectant wipe; do not spray liquids directly on the phone or use solvents. |
| Every 6 months | Check cords and plugs for damage, and confirm the phone is running the firmware version your administrator or provider recommends. |
Troubleshooting
Try these steps before calling for service. For model-specific error messages, consult the manufacturer's manual or your phone system administrator.
| Problem | Possible cause | What to try |
|---|---|---|
| Phone does not power on | Switch port not providing PoE or insufficient power budget; damaged cable. | Try another PoE port or a known-good cable, and confirm the switch can supply Class 2 power; otherwise use the AC adapter if available. |
| "No service" or registration failed | Network or VLAN settings; provisioning error; account not active. | Restart the phone, confirm it obtains an IP address, and ask your administrator or provider to verify the account and provisioning. |
| Choppy audio, echo or one-way audio | Network congestion; firewall/NAT settings; Wi-Fi interference. | Use a wired connection, enable QoS for voice, and have the administrator check firewall SIP and RTP settings. |
| Display or keys unresponsive | Temporary software fault. | Restart the phone by unplugging and reconnecting the network cable. |
Energy use and running costs
The Snom C620 draws 2.1 W in standby — the idle state it spends nearly all of its time in, connected to the network but not on a call. Plugged in 24 hours a day, 365 days a year, that is about 18.4 kWh per year, or $3.13 at $0.17 per kWh.
As a PoE Class 2 device, the phone can draw up to 6.49 W at peak (for example with the backlight on or during a call on speaker), though typical idle draw is the 2.1 W measured above. The switch's own losses come on top of this.
Talk time adds very little energy compared with standby, because calls are short relative to the hours the phone sits idle.
Frequently asked questions
What kind of phone is the Snom C620?
It is a VoIP conference phone.
How much electricity does the Snom C620 use?
It draws 2.1 W in standby, about 18.4 kWh per year — roughly $3.13 at $0.17/kWh if left on continuously.
Can the Snom C620 be powered over Ethernet?
Yes. It is a PoE Class 2 device, so an IEEE 802.3af/at switch or injector can power it over the network cable.
Will the Snom C620 work during a power outage?
Only if the network equipment and PoE switch are on backup power and your phone service is up. Keep another way to call 911.
How many Ethernet ports does the Snom C620 have?
It has one Gigabit Ethernet port.
Sources and disclaimer
Specifications on this page come from the ENERGY STAR certified telephones dataset published by the U.S. Environmental Protection Agency (record certified August 13, 2024), retrieved October 7, 2026.
The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Snom. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Snom or an authorized service provider for warranty repairs and replacement parts.
Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.
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