Chapter 7 Sip Trunking; Section 1 Voip; Section 2 Ip Networking; Section 3 Sip Trunking - NEC Sl2100 Networking Manual

SIP Trunking
S 1 V IP
ECTION O
VoIP (Voice over Internet Protocol or Voice over IP) allows the delivery of voice information using the
Internet protocol (sending data over the Internet using an IP address). This means that digital voice
information can be sent in packets over the Internet rather than using the traditional public switch
telephone network (CO lines). A major advantage of VoIP is that it avoids the tolls charged by ordinary
telephone service.
Using VoIP equipment at a gateway (a network point that acts as an entrance to another network), the
packetized voice transmissions from users in the company are received and routed to other parts of
the company intranet (local area or wide area network) or they can be sent over the Internet using CO
lines to another gateway.
**1
S 2 IP NETWORKING
ECTION
IP Networking uses VoIP technology to connect two or more telephone systems together. This allows
calls to be made between sites without using the public telephone network. This can save money and
make communication between sites much easier.
The following Networking modes are available on the NEC SL2100 system:
• SIP TIE lines
• SIP Trunks (to a SIP Trunk Provider)
S 3 SIP TRUNKING
ECTION
3.1 Introduction
SIP (Session Initiation Protocol) is used for Voice over IP. It is defined by the IETF (Internet
Engineering Task Force) in RFC2543 and RFC3261. SIP trunking is the term used for linking a PBX,
such as the NEC SL2100 system, to the public telephone network by means of VoIP. This provides the
ability for users to place and receive communications and services from any location and for networks
to identify the users wherever they are located.
SIP analyzes requests from clients and retrieves responses from servers then sets call parameters at
either end of the communication, handles call transfer and terminates.
The NEC SL2100 system implementation and programming for SIP are very similar. The call routing,
call features and speech handling (RTP) are the same. Only the signaling protocol is different.
**1. The voice quality of VoIP depends on variables such as available bandwidth, network latency and Quality
of Service (QoS) initiatives, all of which are controlled by the network and Internet Service Providers. Because
these variables are not in NEC control, it cannot guarantee the performance of the user's IP-based remote voice
solution. Therefore, NEC recommends connecting VoIP equipment through a local area network using a Private
IP address.
Networking Manual
7
7-1