xiaoz rented an office with friends in August last year (2023) and then started to solve the office internet problem. After comparison, they finally chose Chengdu Mobile's business broadband. By the end of August last year, the broadband was installed. There were many twists and turns during this period, so it is only now that it is being sorted out and sent out.

The picture above shows the interior of the office.

Why Choose Mobile Business Broadband

After various comparisons, it was found that mobile business broadband has the lowest price among the three major operators and provides the following service commitments:

• Provides a static public network IPV4
• Symmetric uplink and downlink
• Can apply for opening ports 80/443 after filing
• Monthly refund based on different packages, with a minimum refund of 50%

Package chosen by xiaoz

This is the package price sent to xiaoz by the account manager at that time (the price may have changed over time, please refer to the actual price):

xiaoz chose the "Heispeed 300" package (300/month), which includes:

• Default provision of a static IPV4
• Symmetric uplink and downlink with a speed of 200Mbps
• Application for opening ports 80/443
• Monthly refund of 50% (150)

After comprehensive calculation, it costs about 150 yuan per month, which is cost-effective and very suitable for office networks.

Application Materials

Mobile business broadband does not support individual applications, and must be applied in the name of a company (individual business can also apply). xiaoz applied using the individual business license and provided the following materials:

• Business license
• Legal person ID card
• Contact phone number
• Office address
• Official seal (used for signing contracts)

After the documents were submitted, a technician was scheduled to install it a few days later. Installation in the same month does not require payment. For example, if you install it on January 1st, it will be free for January, and you only need to pay the fee for February at the end of January.

About Refund

Refunds are only supported for Chengdu Mobile numbers. You can add up to 5 refund mobile numbers. The account manager will provide a form to fill in the mobile numbers and you can customize the refund amount for each number. For example, xiaoz applied for a 300 yuan broadband package with a 50% refund (150 yuan). When customizing the refund mobile numbers, the total amount should not exceed the refund amount. For example, xiaoz added 3 mobile numbers with a total refund amount of 150 yuan.

• Mobile number A: refund 100 yuan
• Mobile number B: refund 30 yuan
• Mobile number C: refund 20 yuan

Refunds are given on the 1st of each month for the consumption amount of the previous month. For example, if mobile number A consumed 50 yuan last month, but I defined a refund of 100 yuan, only the highest consumption amount will be refunded. In other words, although a refund of 100 yuan was defined, only 50 yuan will be refunded. If the consumption amount of mobile number A exceeds 100 yuan last month, 100 yuan will be refunded on the 1st of the following month.

About Public Network

A default static public network IPV4 address is provided, so DDNS services are not required. The domain name can be directly resolved to the public network IP, and the router can do port mapping. If additional IP addresses are required, they can be added at a cost of 50 yuan each. IPV6 is also supported, and it also costs 50 yuan each.

Opening Ports 80/443

Opening ports 80/443 is more troublesome, as it involves website filing. It took nearly 3 months to complete the process with many twists and turns, but it was finally resolved.

The subject of the domain name filing must be in the name of the company, not in the name of an individual or employee. At first, xiaoz filed with a personal domain name and was told that it was rejected after waiting for a month.

In addition, the filing process of Chengdu Mobile is very outdated and still stuck in the era of physical backdrops and paper verification forms. First, Mobile will send you a large and thick backdrop, which needs to be used by the website administrator. After the backdrop is used, it needs to be returned (really speechless). Now Alibaba Cloud and Tencent Cloud have already digitized the filing process, and compared to that, the filing process of Mobile is still very backward.

Secondly, the review efficiency of Mobile is low. xiaoz urged them repeatedly during the period and it took more than 2 months to complete the entire filing process. After the filing was approved, ports 80/443 were opened, and the filed domain name could be resolved to the IP for use.

IP Being Blocked

After opening ports 80/443 for a short period of time, network anomalies were discovered, manifested as:

• The static IP public network cannot be pinged
• All port mappings are invalid
• Ports 80/443 are not available
• The office can access the public network (out), but the external network cannot access the office (in)

Finally, xiaoz contacted Mobile for assistance and was told that the IP was blocked and needed to contact the account manager for further processing. The result obtained was:

• Reason: The domain name that was not filed was resolved to the public network IP, causing it to be blocked
• Solution: Sign a commitment letter and affix a public application for unblocking

This reason confused xiaoz a bit because xiaoz had always used a filed domain name to resolve to the IP and did not know which domain name was resolved without filing. Finally, Mobile was asked to check, and the result was an unknown domain name, which completely belonged to someone else.

This poses a security risk. If the public network IP is exposed, anyone can freely resolve an unfiled domain name to the public network IP assigned by Mobile, resulting in the IP being blocked. Unlike cloud service providers that automatically block unfiled domain names with firewalls, Mobile's business broadband does not have such a built-in firewall. Mobile technicians informed that it is necessary to purchase an enterprise firewall to implement network policy interception. Finally, xiaoz had to personally use a software firewall to implement a domain name whitelist system.

Finally, a commitment letter was signed and stamped with the official seal to apply for unblocking, and now the IP has been completely restored to normal use.

Conclusion

Chengdu Mobile's business broadband has a relatively high cost performance and is very suitable for company networks. However, if you need to open ports 80/443, you need to go through the domain name filing process, which is cumbersome and time-consuming. When filing, pay attention to keeping the domain name filing subject consistent with the broadband subject and not using an individual subject for filing.

Once ports 80/443 are opened, special attention should be paid to not resolving unfiled domain names to the IP, otherwise the IP will be blocked. It is recommended to use a firewall to implement a domain name whitelist system to avoid unnecessary trouble.