Andrew S. Tanenbaum Edition 5th Exercise 6 Question 2 (Page No. 606)

Question

Primitives of transport service assume asymmetry between the two end points during connection establishment, one end (server) executes LISTEN while the other end (client) executes CONNECT. However, in peer to peer applications such file sharing systems, e.g. BitTorrent, all end points are peers. There is no server or client functionality. How can transport service primitives may be used to build such peer to peer applications?

Answer 1

Answer: In this case, as the peers are the two endpoints, so a separate mechanism is required that tells the endpoints at run time that which end will represent as server and which will represent as a client, including their addresses.

We can achieve this by having a different coordinator process that gives this information to the two endpoints before the connection between them is established.