vpn接続情報参考
http://www.media.hiroshima-u.ac.jp/services/hinet/vpn-pptp-setup-windows7
yamaha ルーター設定の為参考
http://blog.goo.ne.jp/takuminews/e/6440801b3cab40670ba387419cc20e3a
http://www.marronkun.net/network/yamaha/vpn_000053.html
pp auth username [user1] [password1] pp auth username [user2] [password2]