CSL Mobile Roaming in mainland China Experience
Recently I have purchased an HK Mobi prepaid SIM card. The card is essentially a Prepaid HKCSL SIM. My plan includes 12 GB of local data, 12 GB of Greater China Roaming data, 2000 minutes of local call, as well as 38 HK$ of balance.
This post focuses on the roaming experience in mainland China, my primary residence.
Test environment
The test machine is a OnePlus 8, the phone supports 5G, but the card only supports 4G/LTE roaming.
I live in a small city in Jiangsu province, here is the result of NetMonster.
Information comes by default in Android.
The roaming ISP is China Unicom, and this is the ONLY choice.
IP
HKT = PCCW = CSL = Netvigator, so it meets expectations.
Latency
Since this is the first time I test SIM cards, there will only be 2 samples. One is to Google, and the other is to Cloudflare.
To Google.
To Cloudflare.
The result is not amazing at all.
Streaming media
If you have investigated things like media restrictions and IP fraud scores, you may know that there are serveral tiers of IPs, and cellular is the greatest and the lowest fraud score among all.
SpeedTest
I have seen a lot of benchmarkers said that CSL has intentionally limited the roaming LTE speed in mainland China, so I ran two tests. One is multi-thread test, and the other is single-thread test. Both of them uses LTE connection and the same speedtest server.
Multi-thread
Single-thread
It is far from great, especially the single-thread one.
CDN node
| Provider | Node Country | Node ID |
|---|---|---|
| Cloudflare | Hong Kong SAR, China | HKG |
| Fastly | Hong Kong SAR, China | HKG |
| CDN77 | Hong Kong SAR, China | hongkongHK |
| Hong Kong SAR, China | hkg | |
| jsDelivr | ? | Cloudflare |
| AWS CloudFront | Hong Kong SAR, China | HKG60-C1 |
| BunnyCDN, Standard | Hong Kong SAR, China | HK1-1059 |
| BunnyCDN, Volume | Singapore | SG1-714 |
| Vercel | Hong Kong SAR, China | hkg1 |
| G-Core Labs | Hong Kong SAR, China | hk2-hw-gc11 |
| CDN.net | Hong Kong SAR, China | Hong Kong, HK |
| Edgio (LimeLight) | Hong Kong SAR, China | hkg |
| HAProxy Edge | Singapore | sin1 |
| OVH | Canada | bhs |
| CacheFly | Hong Kong SAR, China | hkg1-01 |
Data provided by ip.skk.moe
Conclusion
If you decided to go to mainland China for a trip, then this card can be your choice. This card can be purchased in Hong Kong for an extremely cheap price.