Bandwidth - NEC SL1100 Networking Manual

Issue 6.0
13.7
9 - 40
3. Press 1 on the dial pad for Network Settings.
4. Press 6 on the dial pad for Advanced Settings.
5. Press 4 on the dial pad for Type of Service.
6. There are two options (1) is RTP and (2) is SIP.
7. Press 1 on the dial pad for RTP (voice packets), enter the hexadecimal
value, and then press the OK soft key.
8. Press 2 on the dial pad for SIP (Signaling packets), enter the
hexadecimal value, and then press the OK soft key.
9. If no more changes are to be made, press the Exit soft key three times,
and then press the Save soft key. The phone reboots.

Bandwidth

The bandwidth required for VoIP calls depends on the following factors.
Layer 2 media

CODEC

Packet Size

RTP Header Compression

Voice Activity Detection (VAD)

Number of simultaneous calls

Layer 2 media is concerned with moving data across the physical links in the
network. A few of the most common layer 2 media types are Ethernet, PPP,
and Frame Relay.
CODEC stands for Coder/Decoder and is the conversion of the TDM signal
into an IP signal and vice versa. A CODEC can also compress/decompress
the voice payload to save on bandwidth.
Packet Size is the amount of audio in each PDU (protocol data unit)
measured in milliseconds. The larger the packet the less bandwidth used. This
is because sending larger packets (more milliseconds of voice) requires,
overall, less packets to be sent. The downside of this practice is if a packet is
dropped/lost a larger piece of voice is missing from the conversation as the
system waits the additional delay for the next packet arrival.
NEC SL1100
IP Multiline Station (SIP)