The equation for determining the download time for a peer-to-peer file sharing and client/server file sharing is given below. Dp2p ≥ max(F/us, F/dmin, NF/(us + Σ_{i=1}^{N} ui)) Dcs = max(NF/us, F/dmin) Match the following terms to what they represent i) F/us ii) F/dmin iii) NF/(us + Σ_{i=1}^{N} ui) iv) NF/us 1) Time needed for server to upload one copy of the file 2) Time for cooperating peers + server to upload a copy of the file to all peers 3) Time for server to upload file to all clients 4) Time for slowest peer to download one copy of the file
Try an answer before revealing the guidance below.
Key Concepts
- F: file size
- us: server upload rate
- dmin: slowest download rate
- Aggregate upload capacity
- N copies
Answer Approach
- Read each term as “data ÷ rate”.
- Decide who is uploading or downloading in each term.
- Decide whether one copy or N copies are being moved.
Full Answer
Answer status: Verified against study notes. Revision notes, not an official marking scheme.
i) F/us → 1 (server uploads one copy). ii) F/dmin → 4 (slowest peer downloads one copy). iii) NF/(us + Σui) → 2 (server and cooperating peers together upload a copy to all peers). iv) NF/us → 3 (server alone uploads the file to all clients).
D_p2p ≥ max(F/us, F/dmin, NF/(us + Σui))D_cs ≥ max(NF/us, F/dmin)Shortcuts: K concepts · A approach · F answer · R reviewed · B bookmark · ← / → previous / next