DSL Advances

5.1. Handshake Modulation Method

All ITU-T compliant DSL modems provide support of the handshake mechanism defined in ITU-T Recommendation G.994.1 prior to the core initialization of the specific DSL. The purpose of the handshake is to identify the type of DSL modem at each end of the loop and to negotiate and agree on a common set of parameters for the communication session. As shown in Figure 5.1, handshake sits “in front” of the core DSL modem to operate in preactivation sessions. During the handshake session, the two modems exchange messages negotiating configuration parameters for the communication session. Once the common set of parameters is identified and agreed upon, the handshake session clears down and the core initialization of the ...