[Python-talk] A few more socket related questions

[bruce.labitt at autoliv.com]

Thanks for peoples' observations at PySIG last night.  I heard folks 
muttering why use UDP.  This got me thinking about my decision.  Maybe I 
chose UDP for the wrong reasons.  So allow me a few questions...  Forgive 
me if the questions are malformed, I really don't understand this stuff 
yet.

Using TCP, How would one send a large array >> MTU ?  Does it still need 
to be broken up into chunks?  And the chunk size would be...?  (In UDP a 
chunk is limited to a number slightly less than 2**16)

When would I consider using sendall?

When it comes down to it, what is the real advantage of tcp?  The 
socket.send documentation still says to check the return value for the 
number of bytes sent...  Is it just that tcp keeps trying to send? or that 
it 'guarantees' delivery.  When does it give up?

As I understand it, in tcp the client has to create and destroy a 
socket(s) for each transaction.

How does the client know if all the data is sent?
How does the server know it got everything?

Can the server send data to the client without a request?  (Delayed 
output?)
As seen by the example below:
----------------------------------------------------------------
client sends data for FFT.
                                                        Server starts FFT.
                                                        Server sends I'm 
busy
client receives I'm busy
                                                        Server sends 
results
client receives results
----------------------------------------------------------------
Or should it be more like:
----------------------------------------------------------------
client sends data for FFT
                                                        Server starts FFT.
                                                        no response from 
server
                                                        Server sends 
results
client receives results
----------------------------------------------------------------

Can you tell I've never done this kind of thing before :)

-Bruce

OK, I'm going back to my copy of Beej's Guide to Network Programming, 
where I'll find some answers, and a bit of confusion too...


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