Netfilter – Knowledge and References

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Introduction of Computer Networks

Published in Dijiang Huang, Ankur Chowdhary, Sandeep Pisharody, Software-Defined Networking and Security, 2018

Dijiang Huang, Ankur Chowdhary, Sandeep Pisharody

iptables is a command-line interface to the packet filtering functionality in netfilter. The packet filtering mechanism provided by iptables is organized into three different kinds of structures: tables, chains and targets. Simply put, a table is something that allows you to process packets in specific ways. The default table is the filter table, although there are other tables too. These tables have chains attached to them. These chains are used to inspect traffic at various points, such as when they just arrive on the network interface or just before they are handed over to a process. Rules can be added to them to match specific packets such as TCP packets going to port 80 and associate it with a target. A target decides the fate of a packet, such as allowing or rejecting it.

Studying the Impact of SIP Message Differentiation on the Quality of VoIP Session Control Procedures

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Journal Information

Published in IETE Technical Review, 2021

Jasmina Baraković Husić, Sabina Baraković, Seudin Kasumović

As indicated in Figure 1, the User Agent Client (UAC) sends SIP requests and receives SIP responses, whereas User Agent Server (UAS) receives SIP requests and sends SIP responses [1]. The packet containing all or the part of the SIP request/response is passed to the netfilter representing a framework provided by the Linux kernel that allows various networking-related operations [29]. It is the packet filtering framework that allows specific kernel modules to register callback functions with the kernel’s network stack.