Abstract :
Voice over Internet Protocol (VoIP) is a technology for sending voice
information using the internet with information technology that will be converted
into packet data packets in digital form for the purpose. VoIP is sent on an IP basis,
it can intercept the data packets for later re-listen. Therefore it is necessary to close
the vulnerability. One of the countermeasures is to apply security technology
Virtual Private Network (VPN) on VoIP network. Softether is one of the open source
VPNs that has the advantages of multi platform VPN which means Softether can
accept connections from various VPN protocols. In this research, simulation test is
done by establishing VoIP and VPN connections then analyzing to design delay
parameters, jitter, throughput, and packet loss to determine QoS of VoIP service
on VPN network. The test used 5 scenarios with traffic variation value 0 kbps, 5000
kbps, 10000 kbps, 15000 kbps, and 20000 kbps. Then make an observation using
wireshark application during the call for 90 seconds. Sampling is done 30 times in
each scenario then search the average value for each parameter. Based on
TIPHON standardization the results show that the delay and jitter parameters are
included in good categories while for packet loss decreased quality. This is seen
from packet loss value in scenario with traffic load of 0 kbps and 5000 kbps
included in good category, but decrease in scenario with 10000 kbps traffic load
including medium category and scenario with traffic load 15000 kbps and 20000
kbps including bad category.
Keyword : VoIP, VPN, Softether, QoS, Delay, Throughput, Jitter, Packet Loss