php.ini에 서

; trans sid support is disabled by default.
; Use of trans sid may risk your users security.
; Use this option with caution.
; - User may send URL contains active session ID
;   to other person via. email/irc/etc.
; - URL that contains active session ID may be stored
;   in publically accessible computer.
; - User may access your site with the same session ID
;   always using URL stored in browser's history or bookmarks.
; uway setting
session.use_trans_sid = 1

위 속성을 체크

1로 되어이있을 경우 링크에 자동으로 PHPSESSID=XXXXXXXXXXXXXX 같은게 붙게된다.