Why ? VOIP Analysis using OPNET Objective Assume we have a pre-existing data network The network managers want to merge voice and data network into one Why ? Cost effective, easier to run, manage and maintain Questions to be asked Will my existing network support VoIP and satisfy the standardized QoS? If yes, how many simultaneous VoIP calls can be made without any hardware upgrade

End to End component of VoIP BANDWIDTH REQUIREMENTS ENCODER: Encoder used- PCM (G.711)= 64 Kbps 1 Packet = 20 msec of voice, Therefore 50 Packets/sec 64 Kbps/ 50 * 8= 160 Bytes / Packet PACKETIZER: -Header Information : 66 Bytes -Total Packet Size going through the network : 226 Bytes - 226 * 8 * 50 Packets= 90.4 Kbps BW required for one call DELAY REQUIREMENT D pack= A/D conversion (5 msec)+ Packetization at source (20 msec)= 25 msec D play= Jitter Buffer Delay + De-packetization (5 msec)= 45 msec Therefore the network delay = 150 msec ( Mouth- Ear delay QoS requirement) – 70 = 80 msec

Cisco 2512 Switch 2 Switch 1

Result= 0.80 msec delay in the packet is When 2 min 20 seconds- 50 seconds = 90 seconds And every two seconds three calls are generated, therefore 135 calls can be made in total

Topology

Wireless Delay

Wireless load

Wi-Fi throughput *Traffic received

OPNET academic edition