[1] Emtronix Co. User's manual of embedded network developing module [OL].www.emtronix.com/web/download/shouldread_86.pdf, 2005 (in Chinese).
[2] SIMPSON W. The point-to-point protocol [S]. RFC1661, 1994.
[3] LLOYDL&W B. SIMOSON PPP authentication protocols [S]. RFC1334, 1992.