NEC SL1100, Networking Manual

Page: 246 / 292

Issue 6.0 NEC SL1100
13 - 4 SL Net
Each system will require a VoIPDB, which by default will provide 16 channels to be
shared for all IP related devices (e.g. IP Phones, IP Trunks, SL Net). If more than 16
channels are required at any site, the system must have the following license: SL-IP-
CHANNEL-16 LIC (0042). With this license installed, the system will now have 32
channels to share for all IP devices. Every system that requires 32 ports must
purchase and install this license.
S
ECTION
3
N
ETWORK
R
EQUIREMENTS
The voice quality of VoIP depends on variables such as available bandwidth, network
latency, and quality of service initiatives (QoS), all of which are controlled by the
network and Internet service providers. Because these variables are not within NEC’s
control, the performance of the users IP-based voice solution cannot be guaranteed.
Therefore, NEC recommends connecting the VoIP equipment through a fully
managed data network with Quality of Service (QOS) implemented.
For a network to be suitable for VoIP it must pass specific requirements. The
requirements are:

One-way delay must not exceed 150ms

Round trip delay must not exceed 300ms

Packet loss must not exceed 1%

Data switches must be manageable

No half-duplex equipment may be present in the network

Routers must provide QOS

Depending upon how the QOS policies are built in the network, assignments may be
needed in the CPU (PRG 84-10).

Adequate bandwidth for the estimated VoIP traffic must be available

Refer to Table 13-1 Bandwidth per VoIP Call on page 13-5 for bandwidth calculations.