Audio Over IP

CHAPTER
Switching and Routing	3

In Chapter 2, you saw how AoIP systems leverage the intrinsic power of standard Ethernet switches and IP routers. In fact, most AoIP-specific products are essentially peripheral devices, with a lot of the real work of an AoIP system taking place in the generic switches and routers.

So while they are very much “behind the curtain,” switches and routers are central to AoIP operations, and thus worthy of additional examination.

3.1 LAYERS AND TERMS

To review, we consider the work done by the devices operating at the data link layer (layer 2) as switching, and the most atomic operative units they work with (called protocol data units or PDUs) are referred to as frames. The communication protocol used at this ...