ZyXEL Communications 70 Series User Manual

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ZyWALL 5/35/70 Series User’s Guide
Appendix G PPTP
706
Figure 444   Example Message Exchange between Computer and an ANT
PPP Data Connection
The PPP frames are tunneled between the PNS and PAC over GRE (General Routing 
Encapsulation, RFC 1701, 1702). The individual calls within a tunnel are distinguished using 
the Call ID field in the GRE header.