Mobile Workers
(Software VPN Client)
Home Office LAN
Head Office LAN
Chassis
DSL
/ Cable / Dialup
ADSL
ADSL
Internet
Firewall /
VPN
ADSL
Router
Firewall /
VPN
ADSL
Router
SL2100
Figure 6-2 Virtual Private Network (VPN) Example
When IP address translation is applied to a VoIP packet, the application fails and the communication
path is broken. VoIP packets contain the IP address information and the ports used as part of its
payload. When NAT is applied, only the header parameter is changed, not the payload data that
affects the process of data packets within the VoIP switch and terminal.
The common scenario for remote IP deployment is:
• Implementation of an IP Phone with a public IP address talking with an NEC SL2100 behind NAT.
An example would be a telecommuter.
Implementation of an IP Phone behind a NAT, which connects to the Internet, terminates in a NEC
SL2100 behind a different NAT.
When selecting VPN equipment it is important to consider Quality of Service. Generally, VPN
hardware is connected to Internet connections which are unreliable and out of the control of the
customer. However, it is possible to set prioritization on some VPN units for voice traffic. This does
not solve the unreliability of the Internet, but helps to ensure that the data traffic to and from the LAN
do not impair the quality of the voice traffic. (Refer to
QoS on page 6-1
).
NEC strongly recommends that any VPN hardware used for VoIP has the facility to prioritize voice
traffic.
S
ECTION
5 CODEC AND BANDWIDTH
This section describes CODEC and bandwidth and their application with the NEC SL2100 system.
ISSUE 1.0
SL2100
Networking Manual
6-7
Содержание UNIVERGE SL2100
Страница 1: ...Networking Manual GVT 010798 141 00 GE4 ISSUE 1 0 May 2017...
Страница 10: ...MEMO SL2100 ISSUE 1 0 1 2 Introduction...
Страница 12: ...MEMO SL2100 ISSUE 1 0 2 2 General Information...
Страница 19: ...Figure 4 3 Testing the Network Connection ISSUE 1 0 SL2100 Networking Manual 4 5...
Страница 20: ...MEMO SL2100 ISSUE 1 0 4 6 General IP Configuration...
Страница 42: ...Conditions None Feature Cross Reference None SL2100 ISSUE 1 0 5 22 Program 15 Extension Basic Setup Program 15...
Страница 68: ...MEMO SL2100 ISSUE 1 0 6 22 Network Design Considerations...
Страница 144: ...MEMO SL2100 ISSUE 1 0 9 46 IP Multiline Station SIP...
Страница 195: ...MEMO ISSUE 1 0 SL2100 Networking Manual 13 33...
Страница 196: ...Networking Manual NEC Corporation ISSUE 1 0...