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Speed

Why Video Calls From China Freeze in the Evening, and What Helps

Zoom, Teams, WhatsApp and FaceTime calls need a steady path, not raw speed. Why calls from China freeze in the evening, and the fixes that help.

Updated October 2026.

The short answer

Calls from China freeze in the evening because international links get crowded, which adds delay, jitter and lost packets. A video call needs only about 1 to 4 Mbps, but it needs them steadily. Use a cable instead of Wi-Fi, pause big uploads, test at 8 pm, and pick a low-delay route such as Ultra when every millisecond counts.

Table of contents

Why do calls freeze when the speed test looks fine?

A speed test measures how much data your connection can move in a burst. A call cares about something else: whether small pieces of sound and picture arrive on time, every time.

Video calls need surprisingly little speed. Zoom recommends 1.2 Mbps each way for a one-to-one call in 720p HD, 3.8 Mbps up and 3.0 Mbps down for 1080p, and 60 to 80 kbps for audio only (Zoom Support). Microsoft recommends 1.5 Mbps each way for a one-to-one Teams video call (Microsoft Learn). Almost every home and office line in China has far more than that.

What breaks calls is the quality of the path:

  • Delay (latency). How long each piece takes to arrive. With a long delay, people start talking at the same time and then both stop.
  • Jitter. Delay that keeps changing. The app has to wait for late pieces, so voices turn robotic and video stutters.
  • Lost packets. Pieces that never arrive. A call can't pause to fetch them again, so words drop out and the picture freezes.

Microsoft's own targets for Teams calls, from your computer to Microsoft's network, are a round trip under 100 ms, packet loss under 1% and jitter under 30 ms (Microsoft Learn training). A connection can pass a speed test with a big number and still miss all three.

Why calls get worse in the evening

Calls from China to the rest of the world have to cross China's international links. Microsoft describes China's connections to the global internet as going through "perimeter devices that are prone to high-levels of cross-border network congestion," which "creates packet loss and latency for all Internet traffic going into and out of China," and it singles out audio and video as especially sensitive (Microsoft Learn).

In the evening, households across China are streaming, gaming and calling at the same time. When links fill up, packets queue (more delay), queues rise and fall (more jitter), and some packets are dropped (loss). A download simply slows down and finishes a bit later. A call can't wait, so it freezes. Our guide to why everything slows in the evening covers the wider picture; this one is about calls.

What our network data shows about evenings

Our network data for the 30 days to 19 October 2026 shows how customers' everyday traffic behaved. During China's evening peak (19:00 to 23:59), the median working speed of customer connections was 100% of the level at other times of day across all routes, and 98% on High Speed. So everyday work held steady in the evening.

The best bursts did dip. On High Speed, the median customer's top speed was 50 Mbps in the evening against 80 Mbps at other times; on Ultra, 35 Mbps against 55 Mbps. That matters for a big download, not for a call that needs a few Mbps. For scale, the top speed at least 20 customers reached or beat over the same period was 335 Mbps (network stats).

To be clear about the limits: this is throughput data, not a measurement of call quality. We have not published measured latency, jitter or packet loss yet. Our app shows these typical round trips from Shanghai: about 90 ms to Los Angeles, about 30 to 55 ms to Osaka and about 65 to 95 ms to Singapore. Treat them as typical, not promises.

High Speed or Ultra for calls?

High Speed (our Los Angeles route, counted at 1x) is what we recommend for about 95% of people, video calls included. Family calls, client meetings and webinars are usually fine on it.

Ultra (our Osaka and Singapore routes, counted at 2.5 times) is for calls where every millisecond counts: interpreted meetings, negotiations where people talk over each other, live sales demos, or long days of back-to-back calls. From Shanghai, Singapore is not much quicker than Los Angeles, so Osaka is the low-delay choice for eastern China.

Because Ultra counts 2.5 times, it helps to know what a call uses. These are our estimates for one hour, both directions, calculated from the vendors' published bandwidth figures. Real calls often use less.

Call typeVendor figureData per hour on High SpeedCounted on Ultra
Audio only (Zoom)60 to 80 kbps each wayabout 55 to 70 MBabout 135 to 180 MB
One-to-one video, 720p (Zoom)1.2 Mbps each wayabout 1.1 GBabout 2.7 GB
One-to-one video (Teams, recommended)1.5 Mbps each wayabout 1.35 GBabout 3.4 GB
One-to-one video, 1080p (Zoom)3.8 Mbps up, 3.0 Mbps downabout 3.1 GBabout 7.7 GB

A sensible pattern: stay on High Speed, switch to Ultra for the calls that matter most, then switch back.

How each call app is handled

On a Throughwire router, and in our apps, each service is routed automatically. You can look up any app in our routing directory.

Call appHow it is routedWhat to know
ZoomThrough ThroughwireDesktop app over a cable gives the steadiest calls
Microsoft TeamsThrough ThroughwireSee our Teams and Microsoft 365 guide
Google MeetThrough ThroughwireGoogle services are blocked in mainland China
WhatsAppThrough ThroughwireGreatFire's recent tests of whatsapp.com all showed interference (checked 23 October 2026)
Slack huddles and DiscordThrough ThroughwireSame advice as Zoom
Teams Free (replaced Skype)Through ThroughwireMicrosoft retired Skype on 5 May 2025 (Microsoft Support)
FaceTimeApple services stay on your normal China lineApple's own rules for China apply (below)
WeChat, DingTalk and Tencent MeetingStay on your normal China lineUse none of your Throughwire data

FaceTime in China

FaceTime video calls are supported in mainland China: Apple lists "FaceTime over Cellular" for China Mobile, China Telecom and China Unicom. Apple also says "Group FaceTime, FaceTime Audio, and FaceTime links aren't supported in China mainland," and that creating a FaceTime link isn't supported on iPhones bought in mainland China, wherever you are (Apple Support, checked 23 October 2026).

Apple services are on our direct list, so the router sends Apple's own servers over your normal China line. Throughwire doesn't change how Apple's features work in China. If you need a group call or an audio-only call that FaceTime doesn't offer there, WhatsApp or Teams Free both go through Throughwire.

Checklist: steadier calls tonight

  • Plug in a cable. A network cable from the router to your laptop removes Wi-Fi as a cause. Microsoft notes Wi-Fi networks "aren't necessarily designed or configured to support real-time media."
  • If you must use Wi-Fi, use 5 GHz and sit in the same room as the router. Microsoft says the 5 GHz band is better suited to calls than 2.4 GHz.
  • Place the router well. Central, in the open, off the floor and away from thick walls and metal cabinets.
  • Pause uploads during the call. iCloud Photos, Google Drive, OneDrive, Dropbox and game downloads all share your line, even when they go to Chinese servers.
  • Use the desktop app, not a browser tab, for Zoom, Teams or Meet.
  • Turn your video off if the sound breaks up. Teams already gives audio priority over video when bandwidth runs short.
  • Test at 8 pm on a weekday. Make a 10-minute test call at the time you actually need it, not at noon.
  • Use your home or office line, not a foreign eSIM. Foreign eSIMs and Hong Kong networks route through Hong Kong and are slower; on China Telecom, China Mobile and China Unicom lines we expect full speed.
  • Try Ultra for the important calls, then switch back to High Speed to save data.

When Throughwire isn't the right choice

  • Most of your calls are with people in China. WeChat, DingTalk and Tencent Meeting calls stay on your normal line anyway, so you don't need us for them.
  • Your company already has a private cross-border network. Microsoft recommends carrying Teams and Microsoft 365 over such a network where one exists. Use it.
  • You need guaranteed call quality. We don't guarantee speed or uptime. A call centre that needs a contractual guarantee should look at a cross-border leased line from a licensed carrier; our office internet guide compares the options.
  • Your building's network blocks outbound connections. Some company and campus networks do. No service can fix that from outside; ask the network's administrator.

Common questions

Why does Zoom lag in China in the evening?

Zoom needs only about 1 to 4 Mbps, but steadily. In the evening, China's international links are busiest, which adds delay, jitter and lost packets. A cable, no uploads during the call and a low-delay route help most.

Do WhatsApp calls work in China?

Not reliably on an ordinary Chinese connection: GreatFire's recent tests of whatsapp.com all showed interference. With Throughwire, WhatsApp, including voice and video calls, goes through Throughwire.

Does FaceTime work in China?

FaceTime video calls do. Apple says Group FaceTime, FaceTime Audio and FaceTime links aren't supported in mainland China, and iPhones bought in mainland China can't create FaceTime links anywhere. Apple services stay on your normal line with Throughwire.

Is faster internet the fix for frozen calls?

Usually not. A call uses a few Mbps. Frozen calls come from delay, jitter and lost packets on busy routes and Wi-Fi, which a faster plan doesn't change.

Should I always use Ultra for calls?

No. High Speed suits most calls. Ultra's lower delay is worth its 2.5 times data count for calls where people talk over each other, interpreting or long days of back-to-back meetings.

How do I know if the problem is my Wi-Fi or the route?

Make the same call twice at 8 pm: once over Wi-Fi, once on a cable next to the router. If the cable fixes it, it was the Wi-Fi. If both freeze, try Ultra for the next call.

Details for your IT team

  • Transport: the router runs sing-box and connects with VLESS-REALITY. UDP from call apps is carried inside the tunnel to the exit. QUIC (HTTP/3) to international sites is blocked on the router, so browsers use HTTPS over TCP.
  • Routes: High Speed exits in Los Angeles over China Telecom's premium CN2 GIA route. Ultra exits in Osaka or Singapore.
  • Routing (catalog version 2026.10): zoom.us, zoom.com, microsoft.com, office.com, google.com, whatsapp.com and whatsapp.net go through Throughwire. apple.com, icloud.com and Tencent and DingTalk domains go direct. Anything not identified as China-local goes through Throughwire.
  • Measurement: our published figures come from server telemetry (network stats methodology 1.3.0) and describe customer throughput, not latency, jitter or loss.