which OSI layer handles?

Question

some file transfer is in progress. the connection break s and then later after some time is restored. then on the file transfer continues from the point where it left off, which OSI layer handles this? presentation, application, TCP, IP, Sesssion

Answer 1

First of all, TCP/IP is not OSI (see here). And if the connection really breaks, TCP won't be able to allow for continuation of transfer, it has to be done at a higher level (which is not defined in the TCP stack).

Answer 2

which OSI layer handles this

The OSI session layer would handle it, if you were using OSI layers.