This chapter covers the techniques by which we actually get voice data from one point to another. The session protocols for this purpose are really a kind of “grammar” that governs this transmission, and are in turn built upon the transport layer protocols that make up the TCP/IP protocol stack: namely TCP and UDP. You should have a fundamental understanding of these protocols when troubleshooting certain problems, which is why we are describing them in some detail here. This understanding is not strictly necessary to implement Asterisk, but is nevertheless valuable. As such, this chapter is intended as a reference for the event it is needed.
7.1 Network Protocols
TCP is a protocol that ensures that all the information transmitted ...