Using Links of 3G Cellular Interfaces as Primary Links to Connect to the Internet
3G Access of Branches
Because some branches are located in remote areas, it is difficult to deploy fixed networks. Or, the data service volume is limited, and wired access is expensive. 3G access has become a better choice for these branches. Chain stores and gas stations are typical branches.
Figure 11-1 shows the 3G access scenario of branches. Router_1 and Router_2 are egress gateways of the branches. Branch 1 is used as an example.
- The branch connects to the Internet through the 3G network, and then connects to the headquarters using Internet Protocol Security (IPSec) Virtual Private Network (VPN). IPSec ensures secure data exchanges between the headquarters and branch.
- Because Router_1 is connected to the Internet, the firewall and attack defense function must be enabled on 3G interfaces to ensure network security. To use 3G links effectively, you can enable the P2P traffic limiting function on Router_1. The P2P traffic limiting function is used to block P2P applications such as eMule and BT that consume a large amount of bandwidth.
3G Access for Devices in Buildings
For some devices deployed in buildings, such as off-premise ATMs, it is difficult for the devices to access fixed network resources. Additionally, the location of these devices may change frequently. If wired network access service is deployed, subsequent maintenance workload is heavy. 3G access can solve these problems.
Figure 11-2 shows the 3G access scenario of off-premise ATMs.
- As shown in Figure 11-2, the Router is placed in the ATM. To ensure network reliability and security, the Router must be a 3G router or support 3G interface cards.
- The Router is connected to 3G indoor remote antennas to resolve signal shielding problems of the ATM.
- The Router connects to the 3G network first, and then connects to the branch through IPSec VPN.
- The IPSec VPN can use Public Key Infrastructure (PKI) certificates to improve network security and avoid password loss and theft.
- To prevent information security issues caused by router theft, request carriers to provide dedicated SIM cards and bind the SIM cards with specified base stations.
3G Access at Temporary Sites
Temporary sites, such as construction sites and exhibition sites, require quick network deployment. Using wired access requires a long period of time and has high costs. Nevertheless, the 3G network access can provide fast and low-cost network deployment. Additionally, if the router supports Wi-Fi, cabling is not required at the sites. PCs and mobile terminals of enterprise employees can access the router through Wi-Fi, and then visit the Internet or headquarters through the 3G network.
Figure 11-3 shows the 3G access at a temporary site.
- The router that supports 3G access and Wi-Fi, for example, Router in Figure 11-3, is deployed at the temporary site.
- The Router connects to the Internet through the 3G network.
- IPSec VPN can be configured on the Router to connect the temporary site with the headquarters.
- The Wi-Fi function is enabled on the Router so that PCs and mobile terminals can access the Router through Wi-Fi.
- As the Router is connected to the Internet, the firewall and attack defense function must be enabled on 3G interfaces to ensure network security. To use 3G links effectively, you can enable the P2P traffic limiting function on the Router. The P2P traffic limiting function is used to block P2P applications such as eMule and BT that consume a large amount of bandwidth.
