What is Traffic Filtering?
Traffic filtering is the process of analyzing and managing network packets to allow or block their passage through network devices.
Types of Filtering
- By IP address — whitelists and blacklists
- By ports and protocols — TCP/UDP filters
- By content (DPI) — deep packet inspection
- URL filtering — blocking unwanted websites
Where It’s Used
- On firewalls
- In DPI solutions (e.g., Sinjinat, Sandvine)
- In corporate and provider networks
- On edge routers and BRAS
Examples of Filtering Policies
| Rule Type | Action | Purpose |
|---|---|---|
| Block TCP 445 | Block | Prevent SMB attacks |
| Allow UDP 53 | Allow | Access to DNS |
| Drop HTTP to site.ru | Drop | Content filtering |
Risks Without Filtering
- Malware infiltration
- Bandwidth loss
- Violation of regulations
FAQ
Is this the same as DPI?
No. DPI is a type of filtering, but it analyzes traffic more deeply and in greater detail.
Who manages the filtering?
Network administrators, ISPs, and government services (in cases of regulation).
Conclusion
Traffic filtering is the foundation of network security, access control, and enforcement of company or operator policies.
