Type about:config in the address bar, Then look for the following entries, and make the corresponding changes.

1. network.http.max-connections-per-server =32

2. network.http.max-persistent-connections-per-proxy =16

3. network.http.max-connections = 64

4. network.http.max-persistent-connections-per-server = 10

5. network.http.pipelining = true

6. network.http.pipelining.maxrequests = 200

7. network.http.request.max-start-delay = 0

8. network.http.proxy.pipelining = true

9. network.http.proxy.version = 1.0