I have come across a very interesting podcast on BBC Radio 4 on the current issue of the misuse of English at universities and how lecturers can adapt it to the international students: http://www.bbc.co.uk/programmes/b01r9cr9.
"Generations of students have left lecture halls wondering whether they understood what they just heard. Now, a growing proportion of these learners don't consider English their first language. In the first episode in a new series, Michael Rosen visits Birmingham University to investigate how well the English spoken by foreign students equips them for British university life. And to see how lecturers are adapting to their multilingual audience. And there's feature on Special English, the slowed down, limited vocabulary version of the language developed more than half a century ago as a radio experiment, and which the Voice of America network still uses in its programmes".
I found the discussion on the use of banter with international students as particularly interesting. While banter is definitely a virtue appreciated by home students who come from the same culture as the person who initiates mockery and teasing, it is very often misunderstood by students from a different culture. In most extreme situations, some students would feel upset and excluded from the learning community.
Now, should lecturers avoid banter at all cost? I believe it will be extremely difficult for some to get rid of their 'fine' sense of humour that few will understand: jargon, acronyms known only to locals, references to 3rd league football team, politics, etc. I'm obviously being sarcastic here. The answer is "No"! As long as lecturers engage students in discussions around irony, word-play, puns and slap-sticks - in other words - present the cultural background and familiarise ALL students with the context, they are allowed to joke as much as they want.
Now, how do you familiarise international students with these sometimes bizarre or ambiguous concepts? Explaining them is NOT enough I'm afraid. Use examples, show them some pictures and videos illustrating these concepts, WRITE DOWN difficult words on the board for all to see - I'm sure you can predict which words might be more tricky. Don't be lazy! Do a research on where your students come from, familiarise yourself with current issues from their countries. If you share that with them, they will definitely appreciate it which will certainly lay ground for a potential opportunity to banter.