With regards to Ijaazah, should the student approach the teacher or vice versa?

Assalamu 'alaikum wa rahmatullahi wa barakatuh
 With regards to Ijaazah, should the student approach the teacher or vice versa? To obtain an Ijaazah, is reading the Qur'aan to the accepted standard sufficient or is knowledge of Tajweed rules also a consideration?
Can an Ijaazah be given to a student who reads excellently but has an intermediate level grasp of the rules?
Jazakallahu khair
Wassalamu 'alaikum wa rahmatullahi wa barakatuh

Wa alaikum assalaam wa rahmatullahi wa barakatuh
Definitely the student should approach the teacher.  It should not be expected that the teacher would approach a student for obtaining an ijaazah. 
In general, when getting an ijaazah in the recitation of the Qur'an, it means that one reads correctly and understands the application of the rules at a superior level.  In many cases, tajweed knowledge is examined, and if found deficient, is reviewed with the student and a test given to make sure they are at the level required.  Those who have ijaazah are carrying the Qur'an as revealed to the Prophet Muhammed, peace and blessings of Allah upon him, and have the license to pass it on to others.  It is expected that those with ijaazah have full knowledge of tajweed and is application in recitation so that they can explain this theory to their students and correct any theory misunderstandings. 
The student would need to improve their knowledge of the rules to reach the level of mastery in order to have a strong ijaazah.

We will add that not all sheikhs and sheikhas have the same standards as to what is required in tajweed theory, but almost all require a thorough knowledge of the subject. 
Wa iyyaakum
Wa assalaam alaikum wa rahmatullahi wa barakaatuh