Vodavi ip-7008d Guia Do Utilizador

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December, 2005  

 

Vodavi Telenium

Product Guide 

 

mobility ▪ presence ▪ collaboration ▪ convergence 

 

 

In order to assure good packet voice quality, the network must be engineered to provide 

prioritization for voice packets, and must have enough available bandwidth to carry the traffic 

load without excessive delay, jitter, or packet loss. Note that when the network used is the 

Internet, quality of service can not be assured, due to the lack of control available for Internet 

traffic.  
 

 

The amount of bandwidth taken by VoIP calls depends on the amount of conversation passing 
between the calling parties.  The figures below represent a constant packet data stream from 

constant audio on both sides: 

 

 

Number of simultaneous calls: 

2 4  6  8 

 

348.8 697.6 1046.4 1395.2 

(G.711) 

87.48 174.96 262.44 349.92 

(G.723.1) 

required bandwidth in Kbps 

 
 

These figures only represent the amount of bandwidth taken up by VoIP calls—they are not 

recommended bandwidth minimums. Factors that can add to overhead, increasing bandwidth 

consumption include: 

 

-  VPN – adds overhead and latency due to encryption and tunneling 

-  IPSEC –can increase latency due to encryption 

-  Older equipment – can add latency by requiring that frames be broken into smaller units 

before transmission to the next point on the route