--- title: "callservicesd and CommCenter: what they are, and whether to block them · Kilobat" url: "https://kilobat.app/processes/callservicesd" description: "callservicesd keeps call state on a Mac, and CommCenter lets it make and receive phone calls through an iPhone. What breaks if you block them." --- Apple services # What is callservicesd? `callservicesd` is the macOS call server, and `CommCenter` lets the Mac make and receive phone calls through your iPhone. Their traffic is call signalling and, during a call, audio from the iPhone. Process: `callservicesd` · Also seen as: `CommCenter` · Made by Apple · Applies to: macOS 14 Sonoma and later. Checked on macOS 27.2. · Checked: 1 November 2026 ## Short answer Part of macOS. callservicesd keeps the state of calls, and CommCenter lets the Mac make and receive phone calls through your iPhone. Block with care Blocking them stops phone calls on this Mac. Your iPhone still rings. Turn off calls on the Mac instead. Path `/System/Library/PrivateFrameworks/TelephonyUtilities.framework/callservicesd` `/System/Library/Frameworks/CoreTelephony.framework/Support/CommCenter` launchd label `com.apple.telephonyutilities.callservicesd` `com.apple.CommCenter` Signing identifier `com.apple.TelephonyUtilities` `com.apple.CommCenter` ## What it is The man page says that `callservicesd` “is the system daemon responsible for maintaining call state”. It has no options, and users should not run it manually. The `CommCenter` man page says that it provides functionality to allow phone calls to be made and received on the Mac. It should not be invoked directly. Apple Platform Security says that an incoming call reaches your devices through APNs, end-to-end encrypted like iMessage. When you answer, the audio comes from the iPhone over a secure peer-to-peer connection. ## Why it uses the network - **Incoming and outgoing calls.** Apple says that call notifications and outgoing calls are relayed through APNs between the Mac and the iPhone. - **Call audio.** During a call, the audio travels between the iPhone and the Mac over a peer-to-peer link on the same network. ## How much is normal Without calls, their traffic is small or none. During a call, audio between the iPhone and the Mac is expected. It stays on your local network. Apple says that the Mac must be on the same Wi-Fi network as the iPhone, and signed in to the same Apple Account and FaceTime. ## When it uses a lot, and why - **Long calls on the Mac.** Audio flows for as long as the call lasts, between the Mac and the iPhone. - **Several devices ringing.** Apple says that all configured devices are notified of an incoming call. When one answers, the others stop ringing. ## Is it safe to block? Block with care Blocking them stops phone calls on this Mac. Your iPhone still rings. Turn off calls on the Mac instead. What breaks if you block it - The Mac can't make or receive phone calls through your iPhone. - Call notifications on the Mac stop. - FaceTime call state on the Mac may be affected. Apple doesn't document every use of the call server. Blocking means a firewall rule that refuses its connections. Don’t quit or disable a macOS process to save data: macOS starts it again, and other features depend on it. ## Reduce its use 1. On your iPhone, open Settings › Apps › Phone › Calls on Other Devices. Turn off this Mac. 2. Or, on the Mac, open FaceTime › Settings and turn off iPhone Cellular Calls. Apple Platform Security names this setting. 3. Don't quit these processes in Activity Monitor. macOS starts them again. ## See how much it uses 1. Open Activity Monitor from Applications › Utilities. Click Network. 2. Type `callservicesd` in the search field. The Sent Bytes and Rcvd Bytes columns show what it moved since it started. 3. In Terminal, watch only this process. Press d to show the change per second, and q to quit. ``` nettop -p 'callservicesd' -P ``` ## With Kilobat 1. In the Kilobat app list, search for `callservicesd`. Its row shows the live rate and what it moved today. 2. In Connections, click the ⓘ button on one of its rows. The popover shows this page’s short answer, without going online. 3. In Terminal, ask the same question. Add `--json` for scripts and agents. ``` kilobat explain 'callservicesd' ``` 4. Show its traffic over one day. ``` kilobat bandwidth 'callservicesd' day ``` 5. Through MCP, an AI agent asks `explain_connection` with the process name. It gets the same facts. The live view and the explanations are free. History in the app needs Kilobat Pro. Blocking needs Pro and the network filter: see the [network filter](https://kilobat.app/docs/blocking#filtering), [Protection](https://kilobat.app/docs/blocking#protection) and the [hotspot data saver](https://kilobat.app/save-hotspot-data). ## Hosts it contacts Apple and the maker document these hosts for this feature. A process can also contact others; Kilobat’s Connections tab shows what it actually opens on your Mac. - [*.push.apple.com](https://kilobat.app/hosts/push-apple-com): The Apple Push Notification service (APNs). The Mac keeps one connection to it, so notifications, iMessage, FaceTime calls and iCloud changes can arrive. ## Questions **Does a phone call on the Mac use internet data?** Apple says that the audio comes from the iPhone over a peer-to-peer connection on the same network. The iPhone carries the call on its cellular network. **Why is CommCenter on a Mac without a SIM?** Its man page says that it lets the Mac make and receive phone calls, through your iPhone. ## Sources - callservicesd(8) and CommCenter(8), man pages installed with macOS 27.2 - launchd property lists com.apple.telephonyutilities.callservicesd and com.apple.CommCenter, macOS 27.2 - [Apple Platform Security: iPhone cellular call relay security](https://support.apple.com/guide/security/iphone-cellular-call-relay-security-sec28a79bf17/web) - [Apple Support: Receive phone calls and text messages on your Mac](https://support.apple.com/guide/mac-help/receive-calls-text-messages-mac-mchl1b152152/mac) Checked on 1 November 2026. ## Related - [identityservicesd](https://kilobat.app/processes/identityservicesd): Part of macOS. It is the client of the Apple Identity Service, which finds the keys and devices of the people you message or call. - [apsd](https://kilobat.app/processes/apsd): Part of macOS. It keeps one connection open to Apple's push notification service, so apps and iCloud can tell the Mac that something changed. - [rapportd](https://kilobat.app/processes/rapportd): Part of macOS. It connects this Mac to your other Apple devices on the local network for Handoff, phone calls and other Continuity features. - [imagent](https://kilobat.app/processes/imagent): Part of macOS, not documented by Apple. It is the agent behind the Messages app, in the IMCore framework, so iMessage traffic can show under it.