Several questions about bypass Bypass

1. Why does the bypass function be required?

   Applications of various types of gateway devices connected in the network will process some data packets through the gateway device, and then forward the packets after processing, if the gateway device becomes a single point of failure due to unexpected failure (such as hardware failure, power failure, or software deadlock), the customer's network will be paralyzed. To avoid this situation, bypass devices become an inevitable solution.

2. What are the application scenarios of bypass?

   It can be widely used in various gateway devices, such as DPI devices, firewalls, IPS, UTM, IDP, spam gateways, anti-virus gateways, specialized DDoS devices, and dedicated logical isolation devices in various fields.

3. What is the trigger mode of bypass?

   The bypass trigger methods include:

   1) Power Supply trigger, that is, automatic bypass when the device loses power;

   2) gpio control: when the device is powered on, you can use gpio to control specific ports to switch the bypass function status. (If you need to upgrade the system, you can manually Control Bypass Switching Using commands)

   3) Watchdog. Watchdog is a timer circuit. Generally, there is an input called "dog Feed". In normal mode, if a dog is fed normally within a given period of time, if you cannot properly "Feed the dog", that is, timeout, you need to send a signal to control the gpio, so as to achieve the switching of the bypass function status. When this method is used, watchdog can trigger bypass in case of a software fault.

4. What is the hardware implementation of bypass?

   Bypass is divided into two types: Electrical port bypass and optical port bypass. The electrical port bypass hardware implements the use of relays, and the optical port bypasss hardware implements the use of optical switches.

5. What is the difference between built-in and external bypass?

   Built-in and external bypass are generally set to passive bypass, and their functions are basically the same. The difference is that when a device fails, because the bypass module of the built-in device is fixed inside the device, when we change the device, the network must be interrupted again, and the external device does not need to interrupt the network. Of course, some manufacturers have built-in Bypass design into pluggable boards built in the form of the device, you need to change the device, pull out the board, do not need to interrupt the network, and save room space.