to start the connection:
# /sbin/ifup ppp0

to stop the connection:
# /sbin/ifdown ppp0
>>



Perhaps it is not correct in the sense that ppp0 might not always be the connection that we want to bring up. It might be ppp1, ppp2, etc.
But considering that the wiki is meant for novices using these at there homes, this should work  times out of 10.
I will send a note to the site mods to update this.

--
Yours sincerely,
Dipanjan Chakraborty