Desk phones and apps
Should desk phones be on Wi-Fi or Ethernet?
Use Ethernet for desk phones wherever a cable can reach. A wired connection has steady latency and no interference, and a Power over Ethernet switch powers the phones through the same cable, removing power adapters. Wi-Fi works for a phone on a desk that cannot be cabled, provided it uses a 5 GHz network with good signal, but it competes with every other device and is the first thing to check when quality drops.
Why Ethernet wins for fixed desks
- Consistent latency and no packet loss from interference, which is what voice needs most.
- One cable for power and data with a PoE switch; no power bricks, and phones restart cleanly after a power blip if the switch is on a UPS.
- Most desk phones have a pass-through port, so a desk with one wall jack can connect the phone and the computer.
- Easier troubleshooting: a wired phone that misbehaves is a phone or switch problem, not a Wi-Fi problem.
When Wi-Fi is acceptable
A desk in a room with no cabling, a temporary location, or a home office where running cable is impractical. In those cases use a phone with built-in Wi-Fi or an approved Wi-Fi adapter, connect to a 5 GHz network, and place the access point within clear range. Avoid 2.4 GHz, which is crowded and slower. Keep the phone off guest networks, which often block the traffic it needs.
Cordless DECT handsets are a different case: they use their own radio, not Wi-Fi, and only the base needs an Ethernet connection. For people who roam, DECT is usually the better choice over a Wi-Fi desk phone.
Network settings that matter
A PoE switch sized for the number of phones plus headroom. A separate VLAN for voice if your switch supports it, so phone traffic is isolated and prioritized. Quality of Service on the router so voice is prioritized over downloads and video. SIP ALG disabled on the router, which causes more problems than it solves. A 3CTel specialist reviews these with you or your IT provider before installation.
If your switch does not provide PoE, phones can use power adapters or a small PoE injector per phone. It works, but tidy cabling is harder.
Related questions.
How much bandwidth does each phone need?
A single call uses a small fraction of a typical business connection, roughly 100 kbps each way. The constraint is rarely bandwidth; it is stability, which is why wired connections and QoS matter more than raw speed.
Can I use the computer's Wi-Fi and still have a wired phone?
Yes. The phone's connection and the computer's are independent. If the desk has a jack, wire the phone and let the laptop use Wi-Fi if you prefer.
Will a powerline adapter work instead of running cable?
Sometimes, but powerline links vary with wiring quality and can introduce loss. Treat them as a last resort and test call quality before relying on one.
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