1. FEC SIMULATION IN NS-2
Zhuo Bin Wu (z )

2. FEC
Forward error correction (FEC) - Data transmission where sender adds systematically generated error-correcting code (ECC). Allows correction of a limited number of errors without need for retransmission:
Edge-to-edge (edge router ingress to edge router egress) - recover lost packets at edges
Packet-level
XOR scheme - simplicity & ease of implementation
Recover from loss when there is only one missing data packet
Very effective on TCP traffic

3. DUMBBELL TOPOLOGY Number of edge nodes: N FEC block-size: k
Core-link to edge-link ratio: RE/RC

4. PARAMETERS Core link, RC = 1Gbps; Edge link, RE = 100Mbps & 1000Mbps;
Number of edge nodes, N = 10;
FEC block-size, k = 1, 2, 3, 4, 5, 6, 8, 10 & 15;
Simulation time, t = 15s;
Load = 20% => 200Mbps;
Traffic modeled as a Poisson process;

5. ANALYSIS OF TRACE FILE
- Gawk: pattern scanning and processing language;
[action] [time] [from] [to] [type] [packet size] [source] [destination] [seq. number] [packet ID]

6. RESULTS

7. RESULTS (CONT.)